From 500e5227a08bd603a2943c3c7d2efcaf4a40cc15 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Mon, 13 Feb 2017 00:33:31 +0100
Subject: [PATCH 01/14] WIP SystemCheck library for executing checks from a
 rake task

---
 lib/system_check.rb                 | 12 +++++++++
 lib/system_check/base_check.rb      | 42 +++++++++++++++++++++++++++++
 lib/system_check/base_executor.rb   | 18 +++++++++++++
 lib/system_check/simple_executor.rb | 34 +++++++++++++++++++++++
 lib/tasks/gitlab/check.rake         |  5 ++++
 5 files changed, 111 insertions(+)
 create mode 100644 lib/system_check.rb
 create mode 100644 lib/system_check/base_check.rb
 create mode 100644 lib/system_check/base_executor.rb
 create mode 100644 lib/system_check/simple_executor.rb

diff --git a/lib/system_check.rb b/lib/system_check.rb
new file mode 100644
index 00000000000..1d09b57911a
--- /dev/null
+++ b/lib/system_check.rb
@@ -0,0 +1,12 @@
+module SystemCheck
+  def self.run(component, checks = {}, executor_klass = SimpleExecutor)
+    unless executor_klass.is_a? BaseExecutor
+      raise ArgumentError, 'Invalid executor'
+    end
+
+    executor = executor_klass.new(component)
+    executor.checks = checks.map do |check|
+      raise ArgumentError unless check.is_a? BaseCheck
+    end
+  end
+end
diff --git a/lib/system_check/base_check.rb b/lib/system_check/base_check.rb
new file mode 100644
index 00000000000..6e9f7e509a9
--- /dev/null
+++ b/lib/system_check/base_check.rb
@@ -0,0 +1,42 @@
+module SystemCheck
+  class BaseCheck
+    def check?
+      raise NotImplementedError
+    end
+
+    def show_error
+      raise NotImplementedError
+    end
+
+    def skip?
+      false
+    end
+
+    def skip_message
+    end
+
+    protected
+
+    def try_fixing_it(*steps)
+      steps = steps.shift if steps.first.is_a?(Array)
+
+      puts '  Try fixing it:'.color(:blue)
+      steps.each do |step|
+        puts "  #{step}"
+      end
+    end
+
+    def fix_and_rerun
+      puts '  Please fix the error above and rerun the checks.'.color(:red)
+    end
+
+    def for_more_information(*sources)
+      sources = sources.shift if sources.first.is_a?(Array)
+
+      puts '  For more information see:'.color(:blue)
+      sources.each do |source|
+        puts '  #{source}'
+      end
+    end
+  end
+end
diff --git a/lib/system_check/base_executor.rb b/lib/system_check/base_executor.rb
new file mode 100644
index 00000000000..18319843dea
--- /dev/null
+++ b/lib/system_check/base_executor.rb
@@ -0,0 +1,18 @@
+module SystemCheck
+  class BaseExecutor
+    attr_reader :checks
+    attr_reader :component
+
+    def initialize(component)
+      raise ArgumentError unless component.is_a? String
+
+      @component = component
+      @checks = Set.new
+    end
+
+    def <<(check)
+      raise ArgumentError unless check.is_a? BaseCheck
+      @checks << check
+    end
+  end
+end
diff --git a/lib/system_check/simple_executor.rb b/lib/system_check/simple_executor.rb
new file mode 100644
index 00000000000..2ffe837e326
--- /dev/null
+++ b/lib/system_check/simple_executor.rb
@@ -0,0 +1,34 @@
+module SystemCheck
+  class SimpleExecutor < BaseExecutor
+    def execute
+      start_checking(component)
+
+      @checks.each do |check|
+        print "#{check.name}"
+        if check.skip?
+          puts "skipped #{'('+skip_message+')' if skip_message}".color(:magenta)
+        elsif check.check?
+          puts 'yes'.color(:green)
+        else
+          puts 'no'.color(:red)
+          check.show_error
+        end
+      end
+
+      finished_checking(component)
+    end
+
+    private
+
+    def start_checking(component)
+      puts "Checking #{component.color(:yellow)} ..."
+      puts ''
+    end
+
+    def finished_checking(component)
+      puts ''
+      puts "Checking #{component.color(:yellow)} ... #{"Finished".color(:green)}"
+      puts ''
+    end
+  end
+end
diff --git a/lib/tasks/gitlab/check.rake b/lib/tasks/gitlab/check.rake
index f41c73154f5..88ec9cbc8cc 100644
--- a/lib/tasks/gitlab/check.rake
+++ b/lib/tasks/gitlab/check.rake
@@ -848,10 +848,12 @@ namespace :gitlab do
   # Helper methods
   ##########################
 
+  # @deprecated Please use SystemChecks
   def fix_and_rerun
     puts "  Please fix the error above and rerun the checks.".color(:red)
   end
 
+  # @deprecated Please use SystemChecks
   def for_more_information(*sources)
     sources = sources.shift if sources.first.is_a?(Array)
 
@@ -861,6 +863,7 @@ namespace :gitlab do
     end
   end
 
+  # @deprecated Please use SystemChecks
   def finished_checking(component)
     puts ""
     puts "Checking #{component.color(:yellow)} ... #{"Finished".color(:green)}"
@@ -883,11 +886,13 @@ namespace :gitlab do
     Gitlab.config.gitlab.user
   end
 
+  # @deprecated Please use SystemChecks
   def start_checking(component)
     puts "Checking #{component.color(:yellow)} ..."
     puts ""
   end
 
+  # @deprecated Please use SystemChecks
   def try_fixing_it(*steps)
     steps = steps.shift if steps.first.is_a?(Array)
 

From f182ea4ea5fe76349a584da12e5d4a9f681a8401 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Mon, 13 Feb 2017 09:45:39 +0100
Subject: [PATCH 02/14] Some code-style fixes and documentation

---
 lib/system_check.rb                 | 17 +++++++++---
 lib/system_check/base_check.rb      | 40 +++++++++++++++++++++++++----
 lib/system_check/base_executor.rb   |  6 +++++
 lib/system_check/simple_executor.rb | 30 +++++++++++++++-------
 4 files changed, 76 insertions(+), 17 deletions(-)

diff --git a/lib/system_check.rb b/lib/system_check.rb
index 1d09b57911a..79603dfc7cb 100644
--- a/lib/system_check.rb
+++ b/lib/system_check.rb
@@ -1,12 +1,23 @@
+# Library to perform System Checks
+#
+# Every Check is implemented as its own class inherited from SystemCheck::BaseCheck
+# Execution coordination and boilerplate output is done by the SystemCheck::SimpleExecutor
+#
+# This structure decouples checks from Rake tasks and facilitates unit-testing
 module SystemCheck
-  def self.run(component, checks = {}, executor_klass = SimpleExecutor)
+  # Executes a bunch of checks for specified component
+  #
+  # @param [String] component name of the component relative to the checks being executed
+  # @param [Array<BaseCheck>] checks classes of corresponding checks to be executed in the same order
+  # @param [BaseExecutor] executor_klass optionally specifiy a different executor class
+  def self.run(component, checks = [], executor_klass = SimpleExecutor)
     unless executor_klass.is_a? BaseExecutor
       raise ArgumentError, 'Invalid executor'
     end
 
     executor = executor_klass.new(component)
-    executor.checks = checks.map do |check|
-      raise ArgumentError unless check.is_a? BaseCheck
+    checks.each do |check|
+      executor << check
     end
   end
 end
diff --git a/lib/system_check/base_check.rb b/lib/system_check/base_check.rb
index 6e9f7e509a9..d465711d719 100644
--- a/lib/system_check/base_check.rb
+++ b/lib/system_check/base_check.rb
@@ -1,41 +1,71 @@
 module SystemCheck
+  # Base class for Checks. You must inherit from here
+  # and implement the methods below when necessary
   class BaseCheck
+    # This is where you should implement the main logic that will return
+    # a boolean at the end
+    #
+    # You should not print any output to STDOUT here, use the specific methods instead
+    #
+    # @return [Boolean] whether the check passed or not
     def check?
       raise NotImplementedError
     end
 
+    # This is where you should print detailed information for any error found during #check?
+    #
+    # You may use helper methods to help format the output:
+    #
+    # @see #try_fixing_it
+    # @see #fix_and_rerun
+    # @see #for_more_infromation
     def show_error
       raise NotImplementedError
     end
 
+    # If skip returns true, than no other method on this check will be executed
+    #
+    # @return [Boolean] whether or not this check should be skipped
     def skip?
       false
     end
 
+    # If you enabled #skip? here is where you define a custom message explaining why
+    #
+    # Do not print anything to STDOUT, return a string.
+    #
+    # @return [String] message why this check was skipped
     def skip_message
     end
 
     protected
 
+    # Display a formatted list of instructions on how to fix the issue identified by the #check?
+    #
+    # @param [Array<String>] steps one or short sentences with help how to fix the issue
     def try_fixing_it(*steps)
       steps = steps.shift if steps.first.is_a?(Array)
 
-      puts '  Try fixing it:'.color(:blue)
+      $stdout.puts '  Try fixing it:'.color(:blue)
       steps.each do |step|
-        puts "  #{step}"
+        $stdout.puts "  #{step}"
       end
     end
 
+    # Display a message telling to fix and rerun the checks
     def fix_and_rerun
-      puts '  Please fix the error above and rerun the checks.'.color(:red)
+      $stdout.puts '  Please fix the error above and rerun the checks.'.color(:red)
     end
 
+    # Display a formatted list of references (documentation or links) where to find more information
+    #
+    # @param [Array<String>] sources one or more references (documentation or links)
     def for_more_information(*sources)
       sources = sources.shift if sources.first.is_a?(Array)
 
-      puts '  For more information see:'.color(:blue)
+      $stdout.puts '  For more information see:'.color(:blue)
       sources.each do |source|
-        puts '  #{source}'
+        $stdout.puts '  #{source}'
       end
     end
   end
diff --git a/lib/system_check/base_executor.rb b/lib/system_check/base_executor.rb
index 18319843dea..2c2b33461d9 100644
--- a/lib/system_check/base_executor.rb
+++ b/lib/system_check/base_executor.rb
@@ -1,8 +1,11 @@
 module SystemCheck
+  # @attr_reader [Array<BaseCheck>] checks classes of corresponding checks to be executed in the same order
+  # @attr_reader [String] component name of the component relative to the checks being executed
   class BaseExecutor
     attr_reader :checks
     attr_reader :component
 
+    # @param [String] component name of the component relative to the checks being executed
     def initialize(component)
       raise ArgumentError unless component.is_a? String
 
@@ -10,6 +13,9 @@ module SystemCheck
       @checks = Set.new
     end
 
+    # Add a check to be executed
+    #
+    # @param [BaseCheck] check class
     def <<(check)
       raise ArgumentError unless check.is_a? BaseCheck
       @checks << check
diff --git a/lib/system_check/simple_executor.rb b/lib/system_check/simple_executor.rb
index 2ffe837e326..fc07f09dcb2 100644
--- a/lib/system_check/simple_executor.rb
+++ b/lib/system_check/simple_executor.rb
@@ -1,16 +1,22 @@
 module SystemCheck
+  # Simple Executor is current default executor for GitLab
+  # It is a simple port from display logic in the old check.rake
+  #
+  # There is no concurrency level and the output is progressively
+  # printed into the STDOUT
   class SimpleExecutor < BaseExecutor
+    # Executes defined checks in the specified order and outputs confirmation or error information
     def execute
       start_checking(component)
 
       @checks.each do |check|
-        print "#{check.name}"
+        $stdout.print "#{check.name}"
         if check.skip?
-          puts "skipped #{'('+skip_message+')' if skip_message}".color(:magenta)
+          $stdout.puts "skipped #{'(' + skip_message + ')' if skip_message}".color(:magenta)
         elsif check.check?
-          puts 'yes'.color(:green)
+          $stdout.puts 'yes'.color(:green)
         else
-          puts 'no'.color(:red)
+          $stdout.puts 'no'.color(:red)
           check.show_error
         end
       end
@@ -20,15 +26,21 @@ module SystemCheck
 
     private
 
+    # Prints header content for the series of checks to be executed for this component
+    #
+    # @param [String] component name of the component relative to the checks being executed
     def start_checking(component)
-      puts "Checking #{component.color(:yellow)} ..."
-      puts ''
+      $stdout.puts "Checking #{component.color(:yellow)} ..."
+      $stdout.puts ''
     end
 
+    # Prints footer content for the series of checks executed for this component
+    #
+    # @param [String] component name of the component relative to the checks being executed
     def finished_checking(component)
-      puts ''
-      puts "Checking #{component.color(:yellow)} ... #{"Finished".color(:green)}"
-      puts ''
+      $stdout.puts ''
+      $stdout.puts "Checking #{component.color(:yellow)} ... #{'Finished'.color(:green)}"
+      $stdout.puts ''
     end
   end
 end

From 442735978ca8f3e074a282edfc65c110bd06e079 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Mon, 13 Feb 2017 12:19:28 +0100
Subject: [PATCH 03/14] Move rainbow monkey patch to String to spec_helper

---
 spec/db/production/settings.rb | 1 -
 spec/spec_helper.rb            | 3 +++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/spec/db/production/settings.rb b/spec/db/production/settings.rb
index 007b35bbb77..3cbb173c4cc 100644
--- a/spec/db/production/settings.rb
+++ b/spec/db/production/settings.rb
@@ -1,5 +1,4 @@
 require 'spec_helper'
-require 'rainbow/ext/string'
 
 describe 'seed production settings', lib: true do
   include StubENV
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 4c2eba8fa46..994c7dcbb46 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -26,6 +26,9 @@ if ENV['CI'] && !ENV['NO_KNAPSACK']
   Knapsack::Adapters::RSpecAdapter.bind
 end
 
+# require rainbow gem String monkeypatch, so we can test SystemChecks
+require 'rainbow/ext/string'
+
 # Requires supporting ruby files with custom matchers and macros, etc,
 # in spec/support/ and its subdirectories.
 Dir[Rails.root.join("spec/support/**/*.rb")].each { |f| require f }

From a4460f420bbbac30fbcec3395261c89749b52bbd Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Mon, 13 Feb 2017 12:20:56 +0100
Subject: [PATCH 04/14] Fix a few method signature checks

---
 lib/system_check.rb               | 2 +-
 lib/system_check/base_executor.rb | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/system_check.rb b/lib/system_check.rb
index 79603dfc7cb..ba22a40f5af 100644
--- a/lib/system_check.rb
+++ b/lib/system_check.rb
@@ -11,7 +11,7 @@ module SystemCheck
   # @param [Array<BaseCheck>] checks classes of corresponding checks to be executed in the same order
   # @param [BaseExecutor] executor_klass optionally specifiy a different executor class
   def self.run(component, checks = [], executor_klass = SimpleExecutor)
-    unless executor_klass.is_a? BaseExecutor
+    unless executor_klass < BaseExecutor
       raise ArgumentError, 'Invalid executor'
     end
 
diff --git a/lib/system_check/base_executor.rb b/lib/system_check/base_executor.rb
index 2c2b33461d9..f76f44f3a28 100644
--- a/lib/system_check/base_executor.rb
+++ b/lib/system_check/base_executor.rb
@@ -17,7 +17,7 @@ module SystemCheck
     #
     # @param [BaseCheck] check class
     def <<(check)
-      raise ArgumentError unless check.is_a? BaseCheck
+      raise ArgumentError unless check < BaseCheck
       @checks << check
     end
   end

From bc6d131b74ba4cdf7acadea5a5b7d23f083f47ed Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Mon, 13 Feb 2017 12:21:12 +0100
Subject: [PATCH 05/14] Added specs for SystemCheck and custom matcher

---
 lib/system_check.rb                    |  7 +++++
 spec/lib/system_check_spec.rb          | 39 ++++++++++++++++++++++++++
 spec/support/matchers/execute_check.rb | 19 +++++++++++++
 3 files changed, 65 insertions(+)
 create mode 100644 spec/lib/system_check_spec.rb
 create mode 100644 spec/support/matchers/execute_check.rb

diff --git a/lib/system_check.rb b/lib/system_check.rb
index ba22a40f5af..e9cbf6b8258 100644
--- a/lib/system_check.rb
+++ b/lib/system_check.rb
@@ -15,9 +15,16 @@ module SystemCheck
       raise ArgumentError, 'Invalid executor'
     end
 
+    prepare(component, checks, executor_klass).execute
+  end
+
+  def self.prepare(component, checks = [], executor_klass = SimpleExecutor)
     executor = executor_klass.new(component)
     checks.each do |check|
       executor << check
     end
+
+    executor
   end
+  private_class_method :prepare
 end
diff --git a/spec/lib/system_check_spec.rb b/spec/lib/system_check_spec.rb
new file mode 100644
index 00000000000..399a492ea2e
--- /dev/null
+++ b/spec/lib/system_check_spec.rb
@@ -0,0 +1,39 @@
+require 'spec_helper'
+
+describe SystemCheck, lib: true do
+  subject { SystemCheck }
+
+  describe '.run' do
+    it 'requires custom executor to be a BasicExecutor' do
+      expect { subject.run('Component', [], SystemCheck::SimpleExecutor) }.not_to raise_error
+    end
+
+    context 'custom matcher' do
+      class SimpleCheck < SystemCheck::BaseCheck
+        def check?
+          true
+        end
+      end
+
+      class OtherCheck < SystemCheck::BaseCheck
+        def check?
+          false
+        end
+      end
+
+      subject { SystemCheck }
+
+      it 'detects execution of SimpleCheck' do
+        is_expected.to execute_check(SimpleCheck)
+
+        SystemCheck.run('Test', [SimpleCheck])
+      end
+
+      it 'detects exclusion of OtherCheck in execution' do
+        is_expected.not_to execute_check(OtherCheck)
+
+        SystemCheck.run('Test', [SimpleCheck])
+      end
+    end
+  end
+end
diff --git a/spec/support/matchers/execute_check.rb b/spec/support/matchers/execute_check.rb
new file mode 100644
index 00000000000..9664eb3879d
--- /dev/null
+++ b/spec/support/matchers/execute_check.rb
@@ -0,0 +1,19 @@
+RSpec::Matchers.define :execute_check do |expected|
+  match do |actual|
+    expect(actual).to eq(SystemCheck)
+    expect(actual).to receive(:run) do |*args|
+      expect(args[1]).to include(expected)
+    end
+  end
+
+  match_when_negated do |actual|
+    expect(actual).to eq(SystemCheck)
+    expect(actual).to receive(:run) do |*args|
+      expect(args[1]).not_to include(expected)
+    end
+  end
+
+  failure_message do |actual|
+    return 'This matcher must be used with SystemCheck' unless actual == SystemCheck
+  end
+end

From 45378bdd3aae75cb155677d91be61e3d39f5f515 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Mon, 20 Feb 2017 14:01:37 +0100
Subject: [PATCH 06/14] Added specs for BaseExecutor

---
 spec/lib/system_check/base_executor_spec.rb | 51 +++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 spec/lib/system_check/base_executor_spec.rb

diff --git a/spec/lib/system_check/base_executor_spec.rb b/spec/lib/system_check/base_executor_spec.rb
new file mode 100644
index 00000000000..139f7f3248f
--- /dev/null
+++ b/spec/lib/system_check/base_executor_spec.rb
@@ -0,0 +1,51 @@
+require 'spec_helper'
+
+describe SystemCheck::BaseExecutor, lib: true do
+  class SimpleCheck < SystemCheck::BaseCheck
+    def check?
+      true
+    end
+  end
+
+  class OtherCheck < SystemCheck::BaseCheck
+    def check?
+      false
+    end
+  end
+
+  subject { described_class.new('Test') }
+
+  describe '#component' do
+    it 'returns stored component name' do
+      expect(subject.component).to eq('Test')
+    end
+  end
+
+  describe '#checks' do
+    before do
+      subject << SimpleCheck
+    end
+
+    it 'returns an array of classes' do
+      expect(subject.checks).to include(SimpleCheck)
+    end
+  end
+
+  describe '#<<' do
+    before do
+      subject << SimpleCheck
+    end
+
+    it 'appends a new check to the Set' do
+      subject << OtherCheck
+      stored_checks = subject.checks.to_a
+      expect(stored_checks.first).to eq(SimpleCheck)
+      expect(stored_checks.last).to eq(OtherCheck)
+    end
+
+    it 'inserts unique itens only' do
+      subject << SimpleCheck
+      expect(subject.checks.size).to eq(1)
+    end
+  end
+end

From 13e88c93956b5b350515b919ef7217a3dccf28ff Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Thu, 25 May 2017 16:16:25 +0200
Subject: [PATCH 07/14] Refactor gitlab:app:checks to use SystemCheck

---
 .../app/database_config_exists_check.rb       |  31 ++
 lib/system_check/app/git_config_check.rb      |  50 ++
 lib/system_check/app/git_version_check.rb     |  29 ++
 .../app/gitlab_config_exists_check.rb         |  24 +
 .../app/gitlab_config_not_outdated_check.rb   |  32 ++
 .../app/init_script_exists_check.rb           |  27 +
 .../app/init_script_up_to_date_check.rb       |  44 ++
 lib/system_check/app/log_writable_check.rb    |  28 +
 .../app/migrations_are_up_check.rb            |  20 +
 .../app/orphaned_group_members_check.rb       |  20 +
 .../app/projects_have_namespace_check.rb      |  37 ++
 lib/system_check/app/redis_version_check.rb   |  25 +
 lib/system_check/app/ruby_version_check.rb    |  27 +
 lib/system_check/app/tmp_writable_check.rb    |  28 +
 .../app/uploads_directory_exists_check.rb     |  21 +
 .../app/uploads_path_permission_check.rb      |  36 ++
 .../app/uploads_path_tmp_permission_check.rb  |  40 ++
 lib/system_check/base_check.rb                | 138 +++--
 lib/system_check/helpers.rb                   |  80 +++
 lib/system_check/simple_executor.rb           |  49 +-
 lib/tasks/gitlab/check.rake                   | 493 ++----------------
 lib/tasks/gitlab/task_helpers.rb              |   1 +
 22 files changed, 777 insertions(+), 503 deletions(-)
 create mode 100644 lib/system_check/app/database_config_exists_check.rb
 create mode 100644 lib/system_check/app/git_config_check.rb
 create mode 100644 lib/system_check/app/git_version_check.rb
 create mode 100644 lib/system_check/app/gitlab_config_exists_check.rb
 create mode 100644 lib/system_check/app/gitlab_config_not_outdated_check.rb
 create mode 100644 lib/system_check/app/init_script_exists_check.rb
 create mode 100644 lib/system_check/app/init_script_up_to_date_check.rb
 create mode 100644 lib/system_check/app/log_writable_check.rb
 create mode 100644 lib/system_check/app/migrations_are_up_check.rb
 create mode 100644 lib/system_check/app/orphaned_group_members_check.rb
 create mode 100644 lib/system_check/app/projects_have_namespace_check.rb
 create mode 100644 lib/system_check/app/redis_version_check.rb
 create mode 100644 lib/system_check/app/ruby_version_check.rb
 create mode 100644 lib/system_check/app/tmp_writable_check.rb
 create mode 100644 lib/system_check/app/uploads_directory_exists_check.rb
 create mode 100644 lib/system_check/app/uploads_path_permission_check.rb
 create mode 100644 lib/system_check/app/uploads_path_tmp_permission_check.rb
 create mode 100644 lib/system_check/helpers.rb

diff --git a/lib/system_check/app/database_config_exists_check.rb b/lib/system_check/app/database_config_exists_check.rb
new file mode 100644
index 00000000000..d557cee47b4
--- /dev/null
+++ b/lib/system_check/app/database_config_exists_check.rb
@@ -0,0 +1,31 @@
+module SystemCheck
+  module App
+    class DatabaseConfigExistsCheck < SystemCheck::BaseCheck
+      set_name 'Database config exists?'
+
+      def check?
+        database_config_file = Rails.root.join('config', 'database.yml')
+
+        File.exist?(database_config_file)
+      end
+
+      def show_error
+        try_fixing_it(
+          'Copy config/database.yml.<your db> to config/database.yml',
+          'Check that the information in config/database.yml is correct'
+        )
+        for_more_information(
+          see_database_guide,
+          'http://guides.rubyonrails.org/getting_started.html#configuring-a-database'
+        )
+        fix_and_rerun
+      end
+
+      private
+
+      def see_database_guide
+        'doc/install/databases.md'
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/git_config_check.rb b/lib/system_check/app/git_config_check.rb
new file mode 100644
index 00000000000..7f0c792eb35
--- /dev/null
+++ b/lib/system_check/app/git_config_check.rb
@@ -0,0 +1,50 @@
+module SystemCheck
+  module App
+    class GitConfigCheck < SystemCheck::BaseCheck
+      OPTIONS = {
+        'core.autocrlf' => 'input'
+      }.freeze
+
+      set_name 'Git configured with autocrlf=input?'
+
+      def check?
+        correct_options = OPTIONS.map do |name, value|
+          run_command(%W(#{Gitlab.config.git.bin_path} config --global --get #{name})).try(:squish) == value
+        end
+
+        correct_options.all?
+      end
+
+      def repair!
+        auto_fix_git_config(OPTIONS)
+      end
+
+      def show_error
+        try_fixing_it(
+          sudo_gitlab("\"#{Gitlab.config.git.bin_path}\" config --global core.autocrlf \"#{OPTIONS['core.autocrlf']}\"")
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+      end
+
+      private
+
+      # Tries to configure git itself
+      #
+      # Returns true if all subcommands were successfull (according to their exit code)
+      # Returns false if any or all subcommands failed.
+      def auto_fix_git_config(options)
+        if !@warned_user_not_gitlab
+          command_success = options.map do |name, value|
+            system(*%W(#{Gitlab.config.git.bin_path} config --global #{name} #{value}))
+          end
+
+          command_success.all?
+        else
+          false
+        end
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/git_version_check.rb b/lib/system_check/app/git_version_check.rb
new file mode 100644
index 00000000000..3a128f00911
--- /dev/null
+++ b/lib/system_check/app/git_version_check.rb
@@ -0,0 +1,29 @@
+module SystemCheck
+  module App
+    class GitVersionCheck < SystemCheck::BaseCheck
+      set_name -> { "Git version >= #{self.required_version} ?" }
+      set_check_pass -> { "yes (#{self.current_version})" }
+
+      def self.required_version
+        @required_version ||= Gitlab::VersionInfo.new(2, 7, 3)
+      end
+
+      def self.current_version
+        @current_version ||= Gitlab::VersionInfo.parse(run_command(%W(#{Gitlab.config.git.bin_path} --version)))
+      end
+
+      def check?
+        self.class.current_version.valid? && self.class.required_version <= self.class.current_version
+      end
+
+      def show_error
+        puts "Your git bin path is \"#{Gitlab.config.git.bin_path}\""
+
+        try_fixing_it(
+          "Update your git to a version >= #{self.class.required_version} from #{self.class.current_version}"
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/gitlab_config_exists_check.rb b/lib/system_check/app/gitlab_config_exists_check.rb
new file mode 100644
index 00000000000..247aa0994e4
--- /dev/null
+++ b/lib/system_check/app/gitlab_config_exists_check.rb
@@ -0,0 +1,24 @@
+module SystemCheck
+  module App
+    class GitlabConfigExistsCheck < SystemCheck::BaseCheck
+      set_name 'GitLab config exists?'
+
+      def check?
+        gitlab_config_file = Rails.root.join('config', 'gitlab.yml')
+
+        File.exist?(gitlab_config_file)
+      end
+
+      def show_error
+        try_fixing_it(
+          'Copy config/gitlab.yml.example to config/gitlab.yml',
+          'Update config/gitlab.yml to match your setup'
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/gitlab_config_not_outdated_check.rb b/lib/system_check/app/gitlab_config_not_outdated_check.rb
new file mode 100644
index 00000000000..8a4d7b29977
--- /dev/null
+++ b/lib/system_check/app/gitlab_config_not_outdated_check.rb
@@ -0,0 +1,32 @@
+module SystemCheck
+  module App
+    class GitlabConfigNotOutdatedCheck < SystemCheck::BaseCheck
+      set_name 'GitLab config outdated?'
+      set_check_pass 'no'
+      set_check_fail 'yes'
+      set_skip_reason "can't check because of previous errors"
+
+      def skip?
+        gitlab_config_file = Rails.root.join('config', 'gitlab.yml')
+        !File.exist?(gitlab_config_file)
+      end
+
+      def check?
+        # omniauth or ldap could have been deleted from the file
+        !Gitlab.config['git_host']
+      end
+
+      def show_error
+        try_fixing_it(
+          'Backup your config/gitlab.yml',
+          'Copy config/gitlab.yml.example to config/gitlab.yml',
+          'Update config/gitlab.yml to match your setup'
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/init_script_exists_check.rb b/lib/system_check/app/init_script_exists_check.rb
new file mode 100644
index 00000000000..d246e058e86
--- /dev/null
+++ b/lib/system_check/app/init_script_exists_check.rb
@@ -0,0 +1,27 @@
+module SystemCheck
+  module App
+    class InitScriptExistsCheck < SystemCheck::BaseCheck
+      set_name 'Init script exists?'
+      set_skip_reason 'skipped (omnibus-gitlab has no init script)'
+
+      def skip?
+        omnibus_gitlab?
+      end
+
+      def check?
+        script_path = '/etc/init.d/gitlab'
+        File.exist?(script_path)
+      end
+
+      def show_error
+        try_fixing_it(
+          'Install the init script'
+        )
+        for_more_information(
+          see_installation_guide_section 'Install Init Script'
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/init_script_up_to_date_check.rb b/lib/system_check/app/init_script_up_to_date_check.rb
new file mode 100644
index 00000000000..28c1451b8d2
--- /dev/null
+++ b/lib/system_check/app/init_script_up_to_date_check.rb
@@ -0,0 +1,44 @@
+module SystemCheck
+  module App
+    class InitScriptUpToDateCheck < SystemCheck::BaseCheck
+      SCRIPT_PATH = '/etc/init.d/gitlab'.freeze
+
+      set_name 'Init script up-to-date?'
+      set_skip_reason 'skipped (omnibus-gitlab has no init script)'
+
+      def skip?
+        omnibus_gitlab?
+      end
+
+      def multi_check
+        recipe_path = Rails.root.join('lib/support/init.d/', 'gitlab')
+
+        unless File.exist?(SCRIPT_PATH)
+          puts "can't check because of previous errors".color(:magenta)
+          return
+        end
+
+        recipe_content = File.read(recipe_path)
+        script_content = File.read(SCRIPT_PATH)
+
+        if recipe_content == script_content
+          puts 'yes'.color(:green)
+        else
+          puts 'no'.color(:red)
+          show_error
+        end
+      end
+
+
+      def show_error
+        try_fixing_it(
+          'Re-download the init script'
+        )
+        for_more_information(
+          see_installation_guide_section 'Install Init Script'
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/log_writable_check.rb b/lib/system_check/app/log_writable_check.rb
new file mode 100644
index 00000000000..3e0c436d6ee
--- /dev/null
+++ b/lib/system_check/app/log_writable_check.rb
@@ -0,0 +1,28 @@
+module SystemCheck
+  module App
+    class LogWritableCheck < SystemCheck::BaseCheck
+      set_name 'Log directory writable?'
+
+      def check?
+        File.writable?(log_path)
+      end
+
+      def show_error
+        try_fixing_it(
+          "sudo chown -R gitlab #{log_path}",
+          "sudo chmod -R u+rwX #{log_path}"
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+        fix_and_rerun
+      end
+
+      private
+
+      def log_path
+        Rails.root.join('log')
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/migrations_are_up_check.rb b/lib/system_check/app/migrations_are_up_check.rb
new file mode 100644
index 00000000000..5eedbacce77
--- /dev/null
+++ b/lib/system_check/app/migrations_are_up_check.rb
@@ -0,0 +1,20 @@
+module SystemCheck
+  module App
+    class MigrationsAreUpCheck < SystemCheck::BaseCheck
+      set_name 'All migrations up?'
+
+      def check?
+        migration_status, _ = Gitlab::Popen.popen(%w(bundle exec rake db:migrate:status))
+
+        migration_status !~ /down\s+\d{14}/
+      end
+
+      def show_error
+        try_fixing_it(
+          sudo_gitlab('bundle exec rake db:migrate RAILS_ENV=production')
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/orphaned_group_members_check.rb b/lib/system_check/app/orphaned_group_members_check.rb
new file mode 100644
index 00000000000..2b46d36fe51
--- /dev/null
+++ b/lib/system_check/app/orphaned_group_members_check.rb
@@ -0,0 +1,20 @@
+module SystemCheck
+  module App
+    class OrphanedGroupMembersCheck < SystemCheck::BaseCheck
+      set_name 'Database contains orphaned GroupMembers?'
+      set_check_pass 'no'
+      set_check_fail 'yes'
+
+      def check?
+        !GroupMember.where('user_id not in (select id from users)').exists?
+      end
+
+      def show_error
+        try_fixing_it(
+          'You can delete the orphaned records using something along the lines of:',
+          sudo_gitlab("bundle exec rails runner -e production 'GroupMember.where(\"user_id NOT IN (SELECT id FROM users)\").delete_all'")
+        )
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/projects_have_namespace_check.rb b/lib/system_check/app/projects_have_namespace_check.rb
new file mode 100644
index 00000000000..d21ae225b0b
--- /dev/null
+++ b/lib/system_check/app/projects_have_namespace_check.rb
@@ -0,0 +1,37 @@
+module SystemCheck
+  module App
+    class ProjectsHaveNamespaceCheck < SystemCheck::BaseCheck
+      set_name 'projects have namespace: '
+      set_skip_reason "can't check, you have no projects"
+
+      def skip?
+        !Project.exists?
+      end
+
+      def multi_check
+        puts ''
+
+        Project.find_each(batch_size: 100) do |project|
+          print sanitized_message(project)
+
+          if project.namespace
+            puts 'yes'.color(:green)
+          else
+            puts 'no'.color(:red)
+            show_error
+          end
+        end
+      end
+
+      def show_error
+        try_fixing_it(
+          "Migrate global projects"
+        )
+        for_more_information(
+          "doc/update/5.4-to-6.0.md in section \"#global-projects\""
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/redis_version_check.rb b/lib/system_check/app/redis_version_check.rb
new file mode 100644
index 00000000000..a0610e73576
--- /dev/null
+++ b/lib/system_check/app/redis_version_check.rb
@@ -0,0 +1,25 @@
+module SystemCheck
+  module App
+    class RedisVersionCheck < SystemCheck::BaseCheck
+      MIN_REDIS_VERSION = '2.8.0'.freeze
+      set_name "Redis version >= #{MIN_REDIS_VERSION}?"
+
+      def check?
+        redis_version = run_command(%w(redis-cli --version))
+        redis_version = redis_version.try(:match, /redis-cli (\d+\.\d+\.\d+)/)
+
+        redis_version && (Gem::Version.new(redis_version[1]) > Gem::Version.new(MIN_REDIS_VERSION))
+      end
+
+      def show_error
+        try_fixing_it(
+          "Update your redis server to a version >= #{MIN_REDIS_VERSION}"
+        )
+        for_more_information(
+          'gitlab-public-wiki/wiki/Trouble-Shooting-Guide in section sidekiq'
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/ruby_version_check.rb b/lib/system_check/app/ruby_version_check.rb
new file mode 100644
index 00000000000..37b4d24aa55
--- /dev/null
+++ b/lib/system_check/app/ruby_version_check.rb
@@ -0,0 +1,27 @@
+module SystemCheck
+  module App
+    class RubyVersionCheck < SystemCheck::BaseCheck
+      set_name -> { "Ruby version >= #{self.required_version} ?" }
+      set_check_pass -> { "yes (#{self.current_version})" }
+
+      def self.required_version
+        @required_version ||= Gitlab::VersionInfo.new(2, 1, 0)
+      end
+
+      def self.current_version
+        @current_version ||= Gitlab::VersionInfo.parse(run_command(%w(ruby --version)))
+      end
+
+      def check?
+        self.class.current_version.valid? && self.class.required_version <= self.class.current_version
+      end
+
+      def show_error
+        try_fixing_it(
+          "Update your ruby to a version >= #{self.class.required_version} from #{self.class.current_version}"
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/tmp_writable_check.rb b/lib/system_check/app/tmp_writable_check.rb
new file mode 100644
index 00000000000..99a75e57abf
--- /dev/null
+++ b/lib/system_check/app/tmp_writable_check.rb
@@ -0,0 +1,28 @@
+module SystemCheck
+  module App
+    class TmpWritableCheck < SystemCheck::BaseCheck
+      set_name 'Tmp directory writable?'
+
+      def check?
+        File.writable?(tmp_path)
+      end
+
+      def show_error
+        try_fixing_it(
+          "sudo chown -R gitlab #{tmp_path}",
+          "sudo chmod -R u+rwX #{tmp_path}"
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+        fix_and_rerun
+      end
+
+      private
+
+      def tmp_path
+        Rails.root.join('tmp')
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/uploads_directory_exists_check.rb b/lib/system_check/app/uploads_directory_exists_check.rb
new file mode 100644
index 00000000000..7026d0ba075
--- /dev/null
+++ b/lib/system_check/app/uploads_directory_exists_check.rb
@@ -0,0 +1,21 @@
+module SystemCheck
+  module App
+    class UploadsDirectoryExistsCheck < SystemCheck::BaseCheck
+      set_name 'Uploads directory exists?'
+
+      def check?
+        File.directory?(Rails.root.join('public/uploads'))
+      end
+
+      def show_error
+        try_fixing_it(
+          "sudo -u #{gitlab_user} mkdir #{Rails.root}/public/uploads"
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+        fix_and_rerun
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/uploads_path_permission_check.rb b/lib/system_check/app/uploads_path_permission_check.rb
new file mode 100644
index 00000000000..7df6c060254
--- /dev/null
+++ b/lib/system_check/app/uploads_path_permission_check.rb
@@ -0,0 +1,36 @@
+module SystemCheck
+  module App
+    class UploadsPathPermissionCheck < SystemCheck::BaseCheck
+      set_name 'Uploads directory has correct permissions?'
+      set_skip_reason 'skipped (no uploads folder found)'
+
+      def skip?
+        !File.directory?(rails_uploads_path)
+      end
+
+      def check?
+        File.stat(uploads_fullpath).mode == 040700
+      end
+
+      def show_error
+        try_fixing_it(
+          "sudo chmod 700 #{uploads_fullpath}"
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+        fix_and_rerun
+      end
+
+      private
+
+      def rails_uploads_path
+        Rails.root.join('public/uploads')
+      end
+
+      def uploads_fullpath
+        File.realpath(rails_uploads_path)
+      end
+    end
+  end
+end
diff --git a/lib/system_check/app/uploads_path_tmp_permission_check.rb b/lib/system_check/app/uploads_path_tmp_permission_check.rb
new file mode 100644
index 00000000000..b276a81eac1
--- /dev/null
+++ b/lib/system_check/app/uploads_path_tmp_permission_check.rb
@@ -0,0 +1,40 @@
+module SystemCheck
+  module App
+    class UploadsPathTmpPermissionCheck < SystemCheck::BaseCheck
+      set_name 'Uploads directory tmp has correct permissions?'
+      set_skip_reason 'skipped (no tmp uploads folder yet)'
+
+      def skip?
+        !File.directory?(uploads_fullpath) || !Dir.exist?(upload_path_tmp)
+      end
+
+      def check?
+        # If tmp upload dir has incorrect permissions, assume others do as well
+        # Verify drwx------ permissions
+        File.stat(upload_path_tmp).mode == 040700 && File.owned?(upload_path_tmp)
+      end
+
+      def show_error
+        try_fixing_it(
+          "sudo chown -R #{gitlab_user} #{uploads_fullpath}",
+          "sudo find #{uploads_fullpath} -type f -exec chmod 0644 {} \\;",
+          "sudo find #{uploads_fullpath} -type d -not -path #{uploads_fullpath} -exec chmod 0700 {} \\;"
+        )
+        for_more_information(
+          see_installation_guide_section 'GitLab'
+        )
+        fix_and_rerun
+      end
+
+      private
+
+      def upload_path_tmp
+        File.join(uploads_fullpath, 'tmp')
+      end
+
+      def uploads_fullpath
+        File.realpath(Rails.root.join('public/uploads'))
+      end
+    end
+  end
+end
diff --git a/lib/system_check/base_check.rb b/lib/system_check/base_check.rb
index d465711d719..aff830f54d7 100644
--- a/lib/system_check/base_check.rb
+++ b/lib/system_check/base_check.rb
@@ -2,16 +2,103 @@ module SystemCheck
   # Base class for Checks. You must inherit from here
   # and implement the methods below when necessary
   class BaseCheck
+    include ::Gitlab::TaskHelpers
+    include Helpers
+
+    # Define a custom term for when check passed
+    #
+    # @param [String] term used when check passed (default: 'yes')
+    def self.set_check_pass(term)
+      @check_pass = term
+    end
+
+    # Define a custom term for when check failed
+    #
+    # @param [String] term used when check failed (default: 'no')
+    def self.set_check_fail(term)
+      @check_fail = term
+    end
+
+    # Define the name of the SystemCheck that will be displayed during execution
+    #
+    # @param [String] name of the check
+    def self.set_name(name)
+      @name = name
+    end
+
+    # Define the reason why we skipped the SystemCheck
+    #
+    # This is only used if subclass implements `#skip?`
+    #
+    # @param [String] reason to be displayed
+    def self.set_skip_reason(reason)
+      @skip_reason = reason
+    end
+
+    # Term to be displayed when check passed
+    #
+    # @return [String] term when check passed ('yes' if not re-defined in a subclass)
+    def self.check_pass
+      call_or_return(@check_pass) || 'yes'
+    end
+
+    ## Term to be displayed when check failed
+    #
+    # @return [String] term when check failed ('no' if not re-defined in a subclass)
+    def self.check_fail
+      call_or_return(@check_fail) || 'no'
+    end
+
+    # Name of the SystemCheck defined by the subclass
+    #
+    # @return [String] the name
+    def self.display_name
+      call_or_return(@name) || self.name
+    end
+
+    # Skip reason defined by the subclass
+    #
+    # @return [String] the reason
+    def self.skip_reason
+      call_or_return(@skip_reason) || 'skipped'
+    end
+
+    # Does the check support automatically repair routine?
+    #
+    # @return [Boolean] whether check implemented `#repair!` method or not
+    def can_repair?
+      self.class.instance_methods(false).include?(:repair!)
+    end
+
+    def can_skip?
+      self.class.instance_methods(false).include?(:skip?)
+    end
+
+    def is_multi_check?
+      self.class.instance_methods(false).include?(:multi_check)
+    end
+
+    # Execute the check routine
+    #
     # This is where you should implement the main logic that will return
     # a boolean at the end
     #
     # You should not print any output to STDOUT here, use the specific methods instead
     #
-    # @return [Boolean] whether the check passed or not
+    # @return [Boolean] whether check passed or failed
     def check?
       raise NotImplementedError
     end
 
+    # Execute a custom check that cover multiple unities
+    #
+    # When using multi_check you have to provide the output yourself
+    def multi_check
+      raise NotImplementedError
+    end
+
+    # Prints troubleshooting instructions
+    #
     # This is where you should print detailed information for any error found during #check?
     #
     # You may use helper methods to help format the output:
@@ -23,50 +110,21 @@ module SystemCheck
       raise NotImplementedError
     end
 
-    # If skip returns true, than no other method on this check will be executed
+    # When implemented by a subclass, will attempt to fix the issue automatically
+    def repair!
+      raise NotImplementedError
+    end
+
+    # When implemented by a subclass, will evaluate whether check should be skipped or not
     #
     # @return [Boolean] whether or not this check should be skipped
     def skip?
-      false
+      raise NotImplementedError
     end
 
-    # If you enabled #skip? here is where you define a custom message explaining why
-    #
-    # Do not print anything to STDOUT, return a string.
-    #
-    # @return [String] message why this check was skipped
-    def skip_message
-    end
-
-    protected
-
-    # Display a formatted list of instructions on how to fix the issue identified by the #check?
-    #
-    # @param [Array<String>] steps one or short sentences with help how to fix the issue
-    def try_fixing_it(*steps)
-      steps = steps.shift if steps.first.is_a?(Array)
-
-      $stdout.puts '  Try fixing it:'.color(:blue)
-      steps.each do |step|
-        $stdout.puts "  #{step}"
-      end
-    end
-
-    # Display a message telling to fix and rerun the checks
-    def fix_and_rerun
-      $stdout.puts '  Please fix the error above and rerun the checks.'.color(:red)
-    end
-
-    # Display a formatted list of references (documentation or links) where to find more information
-    #
-    # @param [Array<String>] sources one or more references (documentation or links)
-    def for_more_information(*sources)
-      sources = sources.shift if sources.first.is_a?(Array)
-
-      $stdout.puts '  For more information see:'.color(:blue)
-      sources.each do |source|
-        $stdout.puts '  #{source}'
-      end
+    def self.call_or_return(input)
+      input.respond_to?(:call) ? input.call : input
     end
+    private_class_method :call_or_return
   end
 end
diff --git a/lib/system_check/helpers.rb b/lib/system_check/helpers.rb
new file mode 100644
index 00000000000..91454c99838
--- /dev/null
+++ b/lib/system_check/helpers.rb
@@ -0,0 +1,80 @@
+module SystemCheck
+  module Helpers
+    # Display a message telling to fix and rerun the checks
+    def fix_and_rerun
+      $stdout.puts '  Please fix the error above and rerun the checks.'.color(:red)
+    end
+
+    # Display a formatted list of references (documentation or links) where to find more information
+    #
+    # @param [Array<String>] sources one or more references (documentation or links)
+    def for_more_information(*sources)
+      sources = sources.shift if sources.first.is_a?(Array)
+
+      $stdout.puts '  For more information see:'.color(:blue)
+      sources.each do |source|
+        $stdout.puts "  #{source}"
+      end
+    end
+
+    def see_installation_guide_section(section)
+      "doc/install/installation.md in section \"#{section}\""
+    end
+
+    # @deprecated This will no longer be used when all checks were executed using SystemCheck
+    def finished_checking(component)
+      $stdout.puts ''
+      $stdout.puts "Checking #{component.color(:yellow)} ... #{'Finished'.color(:green)}"
+      $stdout.puts ''
+    end
+
+    # @deprecated This will no longer be used when all checks were executed using SystemCheck
+    def start_checking(component)
+      $stdout.puts "Checking #{component.color(:yellow)} ..."
+      $stdout.puts ''
+    end
+
+    # Display a formatted list of instructions on how to fix the issue identified by the #check?
+    #
+    # @param [Array<String>] steps one or short sentences with help how to fix the issue
+    def try_fixing_it(*steps)
+      steps = steps.shift if steps.first.is_a?(Array)
+
+      $stdout.puts '  Try fixing it:'.color(:blue)
+      steps.each do |step|
+        $stdout.puts "  #{step}"
+      end
+    end
+
+    def sanitized_message(project)
+      if should_sanitize?
+        "#{project.namespace_id.to_s.color(:yellow)}/#{project.id.to_s.color(:yellow)} ... "
+      else
+        "#{project.name_with_namespace.color(:yellow)} ... "
+      end
+    end
+
+    def should_sanitize?
+      if ENV['SANITIZE'] == 'true'
+        true
+      else
+        false
+      end
+    end
+
+    def omnibus_gitlab?
+      Dir.pwd == '/opt/gitlab/embedded/service/gitlab-rails'
+    end
+
+    def gitlab_user
+      Gitlab.config.gitlab.user
+    end
+
+    def sudo_gitlab(command)
+      "sudo -u #{gitlab_user} -H #{command}"
+    end
+  end
+end
+
+
+
diff --git a/lib/system_check/simple_executor.rb b/lib/system_check/simple_executor.rb
index fc07f09dcb2..7a5042047ab 100644
--- a/lib/system_check/simple_executor.rb
+++ b/lib/system_check/simple_executor.rb
@@ -10,20 +10,51 @@ module SystemCheck
       start_checking(component)
 
       @checks.each do |check|
-        $stdout.print "#{check.name}"
-        if check.skip?
-          $stdout.puts "skipped #{'(' + skip_message + ')' if skip_message}".color(:magenta)
-        elsif check.check?
-          $stdout.puts 'yes'.color(:green)
-        else
-          $stdout.puts 'no'.color(:red)
-          check.show_error
-        end
+        run_check(check)
       end
 
       finished_checking(component)
     end
 
+    # Executes a single check
+    #
+    # @param [SystemCheck::BaseCheck] check
+    def run_check(check)
+      $stdout.print "#{check.display_name} ... "
+
+      c = check.new
+
+      # When implements a multi check, we don't control the output
+      if c.is_multi_check?
+        c.multi_check
+        return
+      end
+
+      # When implements skip method, we run it first, and if true, skip the check
+      if c.can_skip? && c.skip?
+        $stdout.puts check.skip_reason.color(:magenta)
+        return
+      end
+
+      if c.check?
+        $stdout.puts check.check_pass.color(:green)
+      else
+        $stdout.puts check.check_fail.color(:red)
+
+        if c.can_repair?
+          $stdout.print 'Trying to fix error automatically. ...'
+          if c.repair!
+            $stdout.puts 'Success'.color(:green)
+            return
+          else
+            $stdout.puts 'Failed'.color(:red)
+          end
+        end
+
+        c.show_error
+      end
+    end
+
     private
 
     # Prints header content for the series of checks to be executed for this component
diff --git a/lib/tasks/gitlab/check.rake b/lib/tasks/gitlab/check.rake
index 88ec9cbc8cc..0d177663066 100644
--- a/lib/tasks/gitlab/check.rake
+++ b/lib/tasks/gitlab/check.rake
@@ -1,5 +1,9 @@
+# Temporary hack, until we migrate all checks to SystemCheck format
+require 'system_check'
+require 'system_check/helpers'
+
 namespace :gitlab do
-  desc "GitLab | Check the configuration of GitLab and its environment"
+  desc 'GitLab | Check the configuration of GitLab and its environment'
   task check: %w{gitlab:gitlab_shell:check
                  gitlab:sidekiq:check
                  gitlab:incoming_email:check
@@ -7,331 +11,38 @@ namespace :gitlab do
                  gitlab:app:check}
 
   namespace :app do
-    desc "GitLab | Check the configuration of the GitLab Rails app"
+    desc 'GitLab | Check the configuration of the GitLab Rails app'
     task check: :environment  do
       warn_user_is_not_gitlab
-      start_checking "GitLab"
 
-      check_git_config
-      check_database_config_exists
-      check_migrations_are_up
-      check_orphaned_group_members
-      check_gitlab_config_exists
-      check_gitlab_config_not_outdated
-      check_log_writable
-      check_tmp_writable
-      check_uploads
-      check_init_script_exists
-      check_init_script_up_to_date
-      check_projects_have_namespace
-      check_redis_version
-      check_ruby_version
-      check_git_version
+      checks = [
+        SystemCheck::App::GitConfigCheck,
+        SystemCheck::App::DatabaseConfigExistsCheck,
+        SystemCheck::App::MigrationsAreUpCheck,
+        SystemCheck::App::OrphanedGroupMembersCheck,
+        SystemCheck::App::GitlabConfigExistsCheck,
+        SystemCheck::App::GitlabConfigNotOutdatedCheck,
+        SystemCheck::App::LogWritableCheck,
+        SystemCheck::App::TmpWritableCheck,
+        SystemCheck::App::UploadsDirectoryExistsCheck,
+        SystemCheck::App::UploadsPathPermissionCheck,
+        SystemCheck::App::UploadsPathTmpPermissionCheck,
+        SystemCheck::App::InitScriptExistsCheck,
+        SystemCheck::App::InitScriptUpToDateCheck,
+        SystemCheck::App::ProjectsHaveNamespaceCheck,
+        SystemCheck::App::RedisVersionCheck,
+        SystemCheck::App::RubyVersionCheck,
+        SystemCheck::App::GitVersionCheck
+      ]
+
+      SystemCheck.run('GitLab', checks)
       check_active_users
-
-      finished_checking "GitLab"
-    end
-
-    # Checks
-    ########################
-
-    def check_git_config
-      print "Git configured with autocrlf=input? ... "
-
-      options = {
-        "core.autocrlf" => "input"
-      }
-
-      correct_options = options.map do |name, value|
-        run_command(%W(#{Gitlab.config.git.bin_path} config --global --get #{name})).try(:squish) == value
-      end
-
-      if correct_options.all?
-        puts "yes".color(:green)
-      else
-        print "Trying to fix Git error automatically. ..."
-
-        if auto_fix_git_config(options)
-          puts "Success".color(:green)
-        else
-          puts "Failed".color(:red)
-          try_fixing_it(
-            sudo_gitlab("\"#{Gitlab.config.git.bin_path}\" config --global core.autocrlf \"#{options["core.autocrlf"]}\"")
-          )
-          for_more_information(
-            see_installation_guide_section "GitLab"
-          )
-        end
-      end
-    end
-
-    def check_database_config_exists
-      print "Database config exists? ... "
-
-      database_config_file = Rails.root.join("config", "database.yml")
-
-      if File.exist?(database_config_file)
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "Copy config/database.yml.<your db> to config/database.yml",
-          "Check that the information in config/database.yml is correct"
-        )
-        for_more_information(
-          see_database_guide,
-          "http://guides.rubyonrails.org/getting_started.html#configuring-a-database"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_gitlab_config_exists
-      print "GitLab config exists? ... "
-
-      gitlab_config_file = Rails.root.join("config", "gitlab.yml")
-
-      if File.exist?(gitlab_config_file)
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "Copy config/gitlab.yml.example to config/gitlab.yml",
-          "Update config/gitlab.yml to match your setup"
-        )
-        for_more_information(
-          see_installation_guide_section "GitLab"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_gitlab_config_not_outdated
-      print "GitLab config outdated? ... "
-
-      gitlab_config_file = Rails.root.join("config", "gitlab.yml")
-      unless File.exist?(gitlab_config_file)
-        puts "can't check because of previous errors".color(:magenta)
-      end
-
-      # omniauth or ldap could have been deleted from the file
-      unless Gitlab.config['git_host']
-        puts "no".color(:green)
-      else
-        puts "yes".color(:red)
-        try_fixing_it(
-          "Backup your config/gitlab.yml",
-          "Copy config/gitlab.yml.example to config/gitlab.yml",
-          "Update config/gitlab.yml to match your setup"
-        )
-        for_more_information(
-          see_installation_guide_section "GitLab"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_init_script_exists
-      print "Init script exists? ... "
-
-      if omnibus_gitlab?
-        puts 'skipped (omnibus-gitlab has no init script)'.color(:magenta)
-        return
-      end
-
-      script_path = "/etc/init.d/gitlab"
-
-      if File.exist?(script_path)
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "Install the init script"
-        )
-        for_more_information(
-          see_installation_guide_section "Install Init Script"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_init_script_up_to_date
-      print "Init script up-to-date? ... "
-
-      if omnibus_gitlab?
-        puts 'skipped (omnibus-gitlab has no init script)'.color(:magenta)
-        return
-      end
-
-      recipe_path = Rails.root.join("lib/support/init.d/", "gitlab")
-      script_path = "/etc/init.d/gitlab"
-
-      unless File.exist?(script_path)
-        puts "can't check because of previous errors".color(:magenta)
-        return
-      end
-
-      recipe_content = File.read(recipe_path)
-      script_content = File.read(script_path)
-
-      if recipe_content == script_content
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "Redownload the init script"
-        )
-        for_more_information(
-          see_installation_guide_section "Install Init Script"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_migrations_are_up
-      print "All migrations up? ... "
-
-      migration_status, _ = Gitlab::Popen.popen(%w(bundle exec rake db:migrate:status))
-
-      unless migration_status =~ /down\s+\d{14}/
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          sudo_gitlab("bundle exec rake db:migrate RAILS_ENV=production")
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_orphaned_group_members
-      print "Database contains orphaned GroupMembers? ... "
-      if GroupMember.where("user_id not in (select id from users)").count > 0
-        puts "yes".color(:red)
-        try_fixing_it(
-          "You can delete the orphaned records using something along the lines of:",
-          sudo_gitlab("bundle exec rails runner -e production 'GroupMember.where(\"user_id NOT IN (SELECT id FROM users)\").delete_all'")
-        )
-      else
-        puts "no".color(:green)
-      end
-    end
-
-    def check_log_writable
-      print "Log directory writable? ... "
-
-      log_path = Rails.root.join("log")
-
-      if File.writable?(log_path)
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "sudo chown -R gitlab #{log_path}",
-          "sudo chmod -R u+rwX #{log_path}"
-        )
-        for_more_information(
-          see_installation_guide_section "GitLab"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_tmp_writable
-      print "Tmp directory writable? ... "
-
-      tmp_path = Rails.root.join("tmp")
-
-      if File.writable?(tmp_path)
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "sudo chown -R gitlab #{tmp_path}",
-          "sudo chmod -R u+rwX #{tmp_path}"
-        )
-        for_more_information(
-          see_installation_guide_section "GitLab"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_uploads
-      print "Uploads directory setup correctly? ... "
-
-      unless File.directory?(Rails.root.join('public/uploads'))
-        puts "no".color(:red)
-        try_fixing_it(
-          "sudo -u #{gitlab_user} mkdir #{Rails.root}/public/uploads"
-        )
-        for_more_information(
-          see_installation_guide_section "GitLab"
-        )
-        fix_and_rerun
-        return
-      end
-
-      upload_path = File.realpath(Rails.root.join('public/uploads'))
-      upload_path_tmp = File.join(upload_path, 'tmp')
-
-      if File.stat(upload_path).mode == 040700
-        unless Dir.exist?(upload_path_tmp)
-          puts 'skipped (no tmp uploads folder yet)'.color(:magenta)
-          return
-        end
-
-        # If tmp upload dir has incorrect permissions, assume others do as well
-        # Verify drwx------ permissions
-        if File.stat(upload_path_tmp).mode == 040700 && File.owned?(upload_path_tmp)
-          puts "yes".color(:green)
-        else
-          puts "no".color(:red)
-          try_fixing_it(
-            "sudo chown -R #{gitlab_user} #{upload_path}",
-            "sudo find #{upload_path} -type f -exec chmod 0644 {} \\;",
-            "sudo find #{upload_path} -type d -not -path #{upload_path} -exec chmod 0700 {} \\;"
-          )
-          for_more_information(
-            see_installation_guide_section "GitLab"
-          )
-          fix_and_rerun
-        end
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "sudo chmod 700 #{upload_path}"
-        )
-        for_more_information(
-          see_installation_guide_section "GitLab"
-        )
-        fix_and_rerun
-      end
-    end
-
-    def check_redis_version
-      min_redis_version = "2.8.0"
-      print "Redis version >= #{min_redis_version}? ... "
-
-      redis_version = run_command(%w(redis-cli --version))
-      redis_version = redis_version.try(:match, /redis-cli (\d+\.\d+\.\d+)/)
-      if redis_version &&
-          (Gem::Version.new(redis_version[1]) > Gem::Version.new(min_redis_version))
-        puts "yes".color(:green)
-      else
-        puts "no".color(:red)
-        try_fixing_it(
-          "Update your redis server to a version >= #{min_redis_version}"
-        )
-        for_more_information(
-          "gitlab-public-wiki/wiki/Trouble-Shooting-Guide in section sidekiq"
-        )
-        fix_and_rerun
-      end
     end
   end
 
   namespace :gitlab_shell do
+    include SystemCheck::Helpers
+
     desc "GitLab | Check the configuration of GitLab Shell"
     task check: :environment  do
       warn_user_is_not_gitlab
@@ -513,33 +224,6 @@ namespace :gitlab do
       end
     end
 
-    def check_projects_have_namespace
-      print "projects have namespace: ... "
-
-      unless Project.count > 0
-        puts "can't check, you have no projects".color(:magenta)
-        return
-      end
-      puts ""
-
-      Project.find_each(batch_size: 100) do |project|
-        print sanitized_message(project)
-
-        if project.namespace
-          puts "yes".color(:green)
-        else
-          puts "no".color(:red)
-          try_fixing_it(
-            "Migrate global projects"
-          )
-          for_more_information(
-            "doc/update/5.4-to-6.0.md in section \"#global-projects\""
-          )
-          fix_and_rerun
-        end
-      end
-    end
-
     # Helper methods
     ########################
 
@@ -565,6 +249,8 @@ namespace :gitlab do
   end
 
   namespace :sidekiq do
+    include SystemCheck::Helpers
+
     desc "GitLab | Check the configuration of Sidekiq"
     task check: :environment  do
       warn_user_is_not_gitlab
@@ -623,6 +309,8 @@ namespace :gitlab do
   end
 
   namespace :incoming_email do
+    include SystemCheck::Helpers
+
     desc "GitLab | Check the configuration of Reply by email"
     task check: :environment  do
       warn_user_is_not_gitlab
@@ -757,6 +445,8 @@ namespace :gitlab do
   end
 
   namespace :ldap do
+    include SystemCheck::Helpers
+
     task :check, [:limit] => :environment do |_, args|
       # Only show up to 100 results because LDAP directories can be very big.
       # This setting only affects the `rake gitlab:check` script.
@@ -812,6 +502,8 @@ namespace :gitlab do
   end
 
   namespace :repo do
+    include SystemCheck::Helpers
+
     desc "GitLab | Check the integrity of the repositories managed by GitLab"
     task check: :environment do
       Gitlab.config.repositories.storages.each do |name, repository_storage|
@@ -826,6 +518,8 @@ namespace :gitlab do
   end
 
   namespace :user do
+    include SystemCheck::Helpers
+
     desc "GitLab | Check the integrity of a specific user's repositories"
     task :check_repos, [:username] => :environment do |t, args|
       username = args[:username] || prompt("Check repository integrity for fsername? ".color(:blue))
@@ -848,60 +542,6 @@ namespace :gitlab do
   # Helper methods
   ##########################
 
-  # @deprecated Please use SystemChecks
-  def fix_and_rerun
-    puts "  Please fix the error above and rerun the checks.".color(:red)
-  end
-
-  # @deprecated Please use SystemChecks
-  def for_more_information(*sources)
-    sources = sources.shift if sources.first.is_a?(Array)
-
-    puts "  For more information see:".color(:blue)
-    sources.each do |source|
-      puts "  #{source}"
-    end
-  end
-
-  # @deprecated Please use SystemChecks
-  def finished_checking(component)
-    puts ""
-    puts "Checking #{component.color(:yellow)} ... #{"Finished".color(:green)}"
-    puts ""
-  end
-
-  def see_database_guide
-    "doc/install/databases.md"
-  end
-
-  def see_installation_guide_section(section)
-    "doc/install/installation.md in section \"#{section}\""
-  end
-
-  def sudo_gitlab(command)
-    "sudo -u #{gitlab_user} -H #{command}"
-  end
-
-  def gitlab_user
-    Gitlab.config.gitlab.user
-  end
-
-  # @deprecated Please use SystemChecks
-  def start_checking(component)
-    puts "Checking #{component.color(:yellow)} ..."
-    puts ""
-  end
-
-  # @deprecated Please use SystemChecks
-  def try_fixing_it(*steps)
-    steps = steps.shift if steps.first.is_a?(Array)
-
-    puts "  Try fixing it:".color(:blue)
-    steps.each do |step|
-      puts "  #{step}"
-    end
-  end
-
   def check_gitlab_shell
     required_version = Gitlab::VersionInfo.new(gitlab_shell_major_version, gitlab_shell_minor_version, gitlab_shell_patch_version)
     current_version = Gitlab::VersionInfo.parse(gitlab_shell_version)
@@ -914,65 +554,10 @@ namespace :gitlab do
     end
   end
 
-  def check_ruby_version
-    required_version = Gitlab::VersionInfo.new(2, 1, 0)
-    current_version = Gitlab::VersionInfo.parse(run_command(%w(ruby --version)))
-
-    print "Ruby version >= #{required_version} ? ... "
-
-    if current_version.valid? && required_version <= current_version
-      puts "yes (#{current_version})".color(:green)
-    else
-      puts "no".color(:red)
-      try_fixing_it(
-        "Update your ruby to a version >= #{required_version} from #{current_version}"
-      )
-      fix_and_rerun
-    end
-  end
-
-  def check_git_version
-    required_version = Gitlab::VersionInfo.new(2, 7, 3)
-    current_version = Gitlab::VersionInfo.parse(run_command(%W(#{Gitlab.config.git.bin_path} --version)))
-
-    puts "Your git bin path is \"#{Gitlab.config.git.bin_path}\""
-    print "Git version >= #{required_version} ? ... "
-
-    if current_version.valid? && required_version <= current_version
-      puts "yes (#{current_version})".color(:green)
-    else
-      puts "no".color(:red)
-      try_fixing_it(
-        "Update your git to a version >= #{required_version} from #{current_version}"
-      )
-      fix_and_rerun
-    end
-  end
-
   def check_active_users
     puts "Active users: #{User.active.count}"
   end
 
-  def omnibus_gitlab?
-    Dir.pwd == '/opt/gitlab/embedded/service/gitlab-rails'
-  end
-
-  def sanitized_message(project)
-    if should_sanitize?
-      "#{project.namespace_id.to_s.color(:yellow)}/#{project.id.to_s.color(:yellow)} ... "
-    else
-      "#{project.name_with_namespace.color(:yellow)} ... "
-    end
-  end
-
-  def should_sanitize?
-    if ENV['SANITIZE'] == "true"
-      true
-    else
-      false
-    end
-  end
-
   def check_repo_integrity(repo_dir)
     puts "\nChecking repo at #{repo_dir.color(:yellow)}"
 
diff --git a/lib/tasks/gitlab/task_helpers.rb b/lib/tasks/gitlab/task_helpers.rb
index e3c9d3b491c..e38e21b149f 100644
--- a/lib/tasks/gitlab/task_helpers.rb
+++ b/lib/tasks/gitlab/task_helpers.rb
@@ -113,6 +113,7 @@ module Gitlab
       end
     end
 
+    # TODO: MIGRATED
     # Tries to configure git itself
     #
     # Returns true if all subcommands were successfull (according to their exit code)

From 27e632758feed94d8b3ff065b7c8928a854cecc5 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Fri, 26 May 2017 01:46:30 +0200
Subject: [PATCH 08/14] Add ActiveUsers Check

---
 lib/system_check/app/active_users_check.rb | 17 +++++++++++++++++
 lib/tasks/gitlab/check.rake                |  8 ++------
 2 files changed, 19 insertions(+), 6 deletions(-)
 create mode 100644 lib/system_check/app/active_users_check.rb

diff --git a/lib/system_check/app/active_users_check.rb b/lib/system_check/app/active_users_check.rb
new file mode 100644
index 00000000000..1d72c8d6903
--- /dev/null
+++ b/lib/system_check/app/active_users_check.rb
@@ -0,0 +1,17 @@
+module SystemCheck
+  module App
+    class ActiveUsersCheck < SystemCheck::BaseCheck
+      set_name 'Active users:'
+
+      def multi_check
+        active_users = User.active.count
+
+        if active_users > 0
+          $stdout.puts active_users.to_s.color(:green)
+        else
+          $stdout.puts active_users.to_s.color(:red)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/tasks/gitlab/check.rake b/lib/tasks/gitlab/check.rake
index 0d177663066..973517c99dd 100644
--- a/lib/tasks/gitlab/check.rake
+++ b/lib/tasks/gitlab/check.rake
@@ -32,11 +32,11 @@ namespace :gitlab do
         SystemCheck::App::ProjectsHaveNamespaceCheck,
         SystemCheck::App::RedisVersionCheck,
         SystemCheck::App::RubyVersionCheck,
-        SystemCheck::App::GitVersionCheck
+        SystemCheck::App::GitVersionCheck,
+        SystemCheck::App::ActiveUsersCheck
       ]
 
       SystemCheck.run('GitLab', checks)
-      check_active_users
     end
   end
 
@@ -554,10 +554,6 @@ namespace :gitlab do
     end
   end
 
-  def check_active_users
-    puts "Active users: #{User.active.count}"
-  end
-
   def check_repo_integrity(repo_dir)
     puts "\nChecking repo at #{repo_dir.color(:yellow)}"
 

From ecdbde3d95b7abf11bae47d3a3b05693d84c27cc Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Fri, 26 May 2017 01:46:54 +0200
Subject: [PATCH 09/14] Improve Specs and some fixes

---
 lib/system_check/base_check.rb                |   4 +-
 lib/system_check/simple_executor.rb           |  12 +-
 lib/tasks/gitlab/task_helpers.rb              |   1 -
 spec/lib/system_check/simple_executor_spec.rb | 179 ++++++++++++++++++
 spec/lib/system_check_spec.rb                 |   5 +
 spec/support/rake_helpers.rb                  |   5 +
 6 files changed, 198 insertions(+), 8 deletions(-)
 create mode 100644 spec/lib/system_check/simple_executor_spec.rb

diff --git a/lib/system_check/base_check.rb b/lib/system_check/base_check.rb
index aff830f54d7..63b7eea5add 100644
--- a/lib/system_check/base_check.rb
+++ b/lib/system_check/base_check.rb
@@ -1,9 +1,11 @@
+require 'tasks/gitlab/task_helpers'
+
 module SystemCheck
   # Base class for Checks. You must inherit from here
   # and implement the methods below when necessary
   class BaseCheck
     include ::Gitlab::TaskHelpers
-    include Helpers
+    include ::SystemCheck::Helpers
 
     # Define a custom term for when check passed
     #
diff --git a/lib/system_check/simple_executor.rb b/lib/system_check/simple_executor.rb
index 7a5042047ab..ad2f549b3fb 100644
--- a/lib/system_check/simple_executor.rb
+++ b/lib/system_check/simple_executor.rb
@@ -24,17 +24,17 @@ module SystemCheck
 
       c = check.new
 
-      # When implements a multi check, we don't control the output
-      if c.is_multi_check?
-        c.multi_check
-        return
-      end
-
       # When implements skip method, we run it first, and if true, skip the check
       if c.can_skip? && c.skip?
         $stdout.puts check.skip_reason.color(:magenta)
         return
       end
+      
+      # When implements a multi check, we don't control the output
+      if c.is_multi_check?
+        c.multi_check
+        return
+      end
 
       if c.check?
         $stdout.puts check.check_pass.color(:green)
diff --git a/lib/tasks/gitlab/task_helpers.rb b/lib/tasks/gitlab/task_helpers.rb
index e38e21b149f..e3c9d3b491c 100644
--- a/lib/tasks/gitlab/task_helpers.rb
+++ b/lib/tasks/gitlab/task_helpers.rb
@@ -113,7 +113,6 @@ module Gitlab
       end
     end
 
-    # TODO: MIGRATED
     # Tries to configure git itself
     #
     # Returns true if all subcommands were successfull (according to their exit code)
diff --git a/spec/lib/system_check/simple_executor_spec.rb b/spec/lib/system_check/simple_executor_spec.rb
new file mode 100644
index 00000000000..f6ba437b71a
--- /dev/null
+++ b/spec/lib/system_check/simple_executor_spec.rb
@@ -0,0 +1,179 @@
+require 'spec_helper'
+require 'rake_helper'
+
+describe SystemCheck::SimpleExecutor, lib: true do
+  class SimpleCheck < SystemCheck::BaseCheck
+    set_name 'my simple check'
+
+    def check?
+      true
+    end
+  end
+
+  class OtherCheck < SystemCheck::BaseCheck
+    set_name 'other check'
+
+    def check?
+      false
+    end
+
+    def show_error
+      $stdout.puts 'this is an error text'
+    end
+  end
+
+  class SkipCheck < SystemCheck::BaseCheck
+    set_name 'skip check'
+    set_skip_reason 'this is a skip reason'
+
+    def skip?
+      true
+    end
+
+    def check?
+      raise 'should not execute this'
+    end
+  end
+
+  class MultiCheck < SystemCheck::BaseCheck
+    set_name 'multi check'
+
+    def multi_check
+      $stdout.puts 'this is a multi output check'
+    end
+
+    def check?
+      raise 'should not execute this'
+    end
+  end
+
+  class SkipMultiCheck < SystemCheck::BaseCheck
+    set_name 'skip multi check'
+
+    def skip?
+      true
+    end
+
+    def multi_check
+      raise 'should not execute this'
+    end
+  end
+
+  class RepairCheck < SystemCheck::BaseCheck
+    set_name 'repair check'
+
+    def check?
+      false
+    end
+
+    def repair!
+      true
+    end
+
+    def show_error
+      $stdout.puts 'this is an error message'
+    end
+  end
+
+  subject { described_class.new('Test') }
+
+  describe '#execute' do
+    before do
+      silence_output
+
+      subject << SimpleCheck
+      subject << OtherCheck
+    end
+
+    it 'runs included checks' do
+      expect(subject).to receive(:run_check).with(SimpleCheck)
+      expect(subject).to receive(:run_check).with(OtherCheck)
+
+      subject.execute
+    end
+  end
+
+  describe '#run_check' do
+    it 'prints check name' do
+      expect(SimpleCheck).to receive(:display_name).and_call_original
+      expect { subject.run_check(SimpleCheck) }.to output(/my simple check/).to_stdout
+    end
+
+    context 'when check pass' do
+      it 'prints yes' do
+        expect_any_instance_of(SimpleCheck).to receive(:check?).and_call_original
+        expect { subject.run_check(SimpleCheck) }.to output(/ \.\.\. yes/).to_stdout
+      end
+    end
+
+    context 'when check fails' do
+      it 'prints no' do
+        expect_any_instance_of(OtherCheck).to receive(:check?).and_call_original
+        expect { subject.run_check(OtherCheck) }.to output(/ \.\.\. no/).to_stdout
+      end
+
+      it 'displays error message from #show_error' do
+        expect_any_instance_of(OtherCheck).to receive(:show_error).and_call_original
+        expect { subject.run_check(OtherCheck) }.to output(/this is an error text/).to_stdout
+      end
+
+      context 'when check implements #repair!' do
+        it 'executes #repair!' do
+          expect_any_instance_of(RepairCheck).to receive(:repair!)
+          subject.run_check(RepairCheck)
+        end
+
+        context 'when repair succeeds' do
+          it 'does not execute #show_error' do
+            expect_any_instance_of(RepairCheck).to receive(:repair!).and_call_original
+            expect_any_instance_of(RepairCheck).not_to receive(:show_error)
+            subject.run_check(RepairCheck)
+          end
+        end
+
+        context 'when repair fails' do
+          it 'does not execute #show_error' do
+            expect_any_instance_of(RepairCheck).to receive(:repair!) { false }
+            expect_any_instance_of(RepairCheck).to receive(:show_error)
+            subject.run_check(RepairCheck)
+          end
+        end
+      end
+    end
+
+    context 'when check implements skip?' do
+      it 'executes #skip? method' do
+        expect_any_instance_of(SkipCheck).to receive(:skip?).and_call_original
+        subject.run_check(SkipCheck)
+      end
+
+      it 'displays #skip_reason' do
+        expect { subject.run_check(SkipCheck) }.to output(/this is a skip reason/).to_stdout
+      end
+
+      it 'does not execute #check when #skip? is true' do
+        expect_any_instance_of(SkipCheck).not_to receive(:check?)
+        subject.run_check(SkipCheck)
+      end
+    end
+
+    context 'when implements a #multi_check' do
+      it 'executes #multi_check method' do
+        expect_any_instance_of(MultiCheck).to receive(:multi_check)
+        subject.run_check(MultiCheck)
+      end
+
+      it 'does not execute #check method' do
+        expect_any_instance_of(MultiCheck).not_to receive(:check)
+        subject.run_check(MultiCheck)
+      end
+
+      context 'when check implements #skip?' do
+        it 'executes #skip? method' do
+          expect_any_instance_of(SkipMultiCheck).to receive(:skip?).and_call_original
+          subject.run_check(SkipMultiCheck)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/system_check_spec.rb b/spec/lib/system_check_spec.rb
index 399a492ea2e..d2087ad2d83 100644
--- a/spec/lib/system_check_spec.rb
+++ b/spec/lib/system_check_spec.rb
@@ -1,8 +1,13 @@
 require 'spec_helper'
+require 'rake_helper'
 
 describe SystemCheck, lib: true do
   subject { SystemCheck }
 
+  before do
+    silence_output
+  end
+
   describe '.run' do
     it 'requires custom executor to be a BasicExecutor' do
       expect { subject.run('Component', [], SystemCheck::SimpleExecutor) }.not_to raise_error
diff --git a/spec/support/rake_helpers.rb b/spec/support/rake_helpers.rb
index 4a8158ed79b..5cb415111d2 100644
--- a/spec/support/rake_helpers.rb
+++ b/spec/support/rake_helpers.rb
@@ -7,4 +7,9 @@ module RakeHelpers
   def stub_warn_user_is_not_gitlab
     allow_any_instance_of(Object).to receive(:warn_user_is_not_gitlab)
   end
+
+  def silence_output
+    allow($stdout).to receive(:puts)
+    allow($stdout).to receive(:print)
+  end
 end

From bca5603740f77667dda6355c457ad1791b4fa42e Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Fri, 26 May 2017 02:34:25 +0200
Subject: [PATCH 10/14] Fix codestyle

---
 lib/system_check/app/git_version_check.rb             | 2 +-
 lib/system_check/app/init_script_up_to_date_check.rb  | 7 +++----
 lib/system_check/app/projects_have_namespace_check.rb | 8 ++++----
 lib/system_check/helpers.rb                           | 3 ---
 4 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/lib/system_check/app/git_version_check.rb b/lib/system_check/app/git_version_check.rb
index 3a128f00911..c388682dfb4 100644
--- a/lib/system_check/app/git_version_check.rb
+++ b/lib/system_check/app/git_version_check.rb
@@ -17,7 +17,7 @@ module SystemCheck
       end
 
       def show_error
-        puts "Your git bin path is \"#{Gitlab.config.git.bin_path}\""
+        $stdout.puts "Your git bin path is \"#{Gitlab.config.git.bin_path}\""
 
         try_fixing_it(
           "Update your git to a version >= #{self.class.required_version} from #{self.class.current_version}"
diff --git a/lib/system_check/app/init_script_up_to_date_check.rb b/lib/system_check/app/init_script_up_to_date_check.rb
index 28c1451b8d2..015c7ed1731 100644
--- a/lib/system_check/app/init_script_up_to_date_check.rb
+++ b/lib/system_check/app/init_script_up_to_date_check.rb
@@ -14,7 +14,7 @@ module SystemCheck
         recipe_path = Rails.root.join('lib/support/init.d/', 'gitlab')
 
         unless File.exist?(SCRIPT_PATH)
-          puts "can't check because of previous errors".color(:magenta)
+          $stdout.puts "can't check because of previous errors".color(:magenta)
           return
         end
 
@@ -22,14 +22,13 @@ module SystemCheck
         script_content = File.read(SCRIPT_PATH)
 
         if recipe_content == script_content
-          puts 'yes'.color(:green)
+          $stdout.puts 'yes'.color(:green)
         else
-          puts 'no'.color(:red)
+          $stdout.puts 'no'.color(:red)
           show_error
         end
       end
 
-
       def show_error
         try_fixing_it(
           'Re-download the init script'
diff --git a/lib/system_check/app/projects_have_namespace_check.rb b/lib/system_check/app/projects_have_namespace_check.rb
index d21ae225b0b..c70633a6d4f 100644
--- a/lib/system_check/app/projects_have_namespace_check.rb
+++ b/lib/system_check/app/projects_have_namespace_check.rb
@@ -9,15 +9,15 @@ module SystemCheck
       end
 
       def multi_check
-        puts ''
+        $stdout.puts ''
 
         Project.find_each(batch_size: 100) do |project|
-          print sanitized_message(project)
+          $stdout.print sanitized_message(project)
 
           if project.namespace
-            puts 'yes'.color(:green)
+            $stdout.puts 'yes'.color(:green)
           else
-            puts 'no'.color(:red)
+            $stdout.puts 'no'.color(:red)
             show_error
           end
         end
diff --git a/lib/system_check/helpers.rb b/lib/system_check/helpers.rb
index 91454c99838..0a6be42a7d1 100644
--- a/lib/system_check/helpers.rb
+++ b/lib/system_check/helpers.rb
@@ -75,6 +75,3 @@ module SystemCheck
     end
   end
 end
-
-
-

From 3f187751d40a687ab9b76857c04849bab0f84357 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Tue, 30 May 2017 19:06:58 +0200
Subject: [PATCH 11/14] Fixed and improved some existing checks and SystemCheck
 library

---
 lib/system_check.rb                           | 15 ++-------
 .../app/database_config_exists_check.rb       |  8 +----
 lib/system_check/app/git_config_check.rb      | 32 +++++++------------
 ...k.rb => gitlab_config_up_to_date_check.rb} |  8 ++---
 .../app/projects_have_namespace_check.rb      |  2 +-
 lib/system_check/app/ruby_version_check.rb    |  2 +-
 lib/system_check/base_check.rb                |  3 --
 lib/system_check/helpers.rb                   | 13 ++++++--
 lib/system_check/simple_executor.rb           | 30 ++++++++---------
 lib/tasks/gitlab/check.rake                   |  2 +-
 lib/tasks/gitlab/task_helpers.rb              | 19 +++++------
 spec/lib/system_check/base_executor_spec.rb   |  4 ++-
 12 files changed, 61 insertions(+), 77 deletions(-)
 rename lib/system_check/app/{gitlab_config_not_outdated_check.rb => gitlab_config_up_to_date_check.rb} (77%)

diff --git a/lib/system_check.rb b/lib/system_check.rb
index e9cbf6b8258..466c39904fa 100644
--- a/lib/system_check.rb
+++ b/lib/system_check.rb
@@ -9,22 +9,13 @@ module SystemCheck
   #
   # @param [String] component name of the component relative to the checks being executed
   # @param [Array<BaseCheck>] checks classes of corresponding checks to be executed in the same order
-  # @param [BaseExecutor] executor_klass optionally specifiy a different executor class
-  def self.run(component, checks = [], executor_klass = SimpleExecutor)
-    unless executor_klass < BaseExecutor
-      raise ArgumentError, 'Invalid executor'
-    end
+  def self.run(component, checks = [])
+    executor = SimpleExecutor.new(component)
 
-    prepare(component, checks, executor_klass).execute
-  end
-
-  def self.prepare(component, checks = [], executor_klass = SimpleExecutor)
-    executor = executor_klass.new(component)
     checks.each do |check|
       executor << check
     end
 
-    executor
+    executor.execute
   end
-  private_class_method :prepare
 end
diff --git a/lib/system_check/app/database_config_exists_check.rb b/lib/system_check/app/database_config_exists_check.rb
index d557cee47b4..d1fae192350 100644
--- a/lib/system_check/app/database_config_exists_check.rb
+++ b/lib/system_check/app/database_config_exists_check.rb
@@ -15,17 +15,11 @@ module SystemCheck
           'Check that the information in config/database.yml is correct'
         )
         for_more_information(
-          see_database_guide,
+          'doc/install/databases.md',
           'http://guides.rubyonrails.org/getting_started.html#configuring-a-database'
         )
         fix_and_rerun
       end
-
-      private
-
-      def see_database_guide
-        'doc/install/databases.md'
-      end
     end
   end
 end
diff --git a/lib/system_check/app/git_config_check.rb b/lib/system_check/app/git_config_check.rb
index 7f0c792eb35..198867f7ac6 100644
--- a/lib/system_check/app/git_config_check.rb
+++ b/lib/system_check/app/git_config_check.rb
@@ -5,7 +5,7 @@ module SystemCheck
         'core.autocrlf' => 'input'
       }.freeze
 
-      set_name 'Git configured with autocrlf=input?'
+      set_name 'Git configured correctly?'
 
       def check?
         correct_options = OPTIONS.map do |name, value|
@@ -15,8 +15,18 @@ module SystemCheck
         correct_options.all?
       end
 
+      # Tries to configure git itself
+      #
+      # Returns true if all subcommands were successful (according to their exit code)
+      # Returns false if any or all subcommands failed.
       def repair!
-        auto_fix_git_config(OPTIONS)
+        return false unless is_gitlab_user?
+
+        command_success = OPTIONS.map do |name, value|
+          system(*%W(#{Gitlab.config.git.bin_path} config --global #{name} #{value}))
+        end
+
+        command_success.all?
       end
 
       def show_error
@@ -27,24 +37,6 @@ module SystemCheck
           see_installation_guide_section 'GitLab'
         )
       end
-
-      private
-
-      # Tries to configure git itself
-      #
-      # Returns true if all subcommands were successfull (according to their exit code)
-      # Returns false if any or all subcommands failed.
-      def auto_fix_git_config(options)
-        if !@warned_user_not_gitlab
-          command_success = options.map do |name, value|
-            system(*%W(#{Gitlab.config.git.bin_path} config --global #{name} #{value}))
-          end
-
-          command_success.all?
-        else
-          false
-        end
-      end
     end
   end
 end
diff --git a/lib/system_check/app/gitlab_config_not_outdated_check.rb b/lib/system_check/app/gitlab_config_up_to_date_check.rb
similarity index 77%
rename from lib/system_check/app/gitlab_config_not_outdated_check.rb
rename to lib/system_check/app/gitlab_config_up_to_date_check.rb
index 8a4d7b29977..c609e48e133 100644
--- a/lib/system_check/app/gitlab_config_not_outdated_check.rb
+++ b/lib/system_check/app/gitlab_config_up_to_date_check.rb
@@ -1,9 +1,7 @@
 module SystemCheck
   module App
-    class GitlabConfigNotOutdatedCheck < SystemCheck::BaseCheck
-      set_name 'GitLab config outdated?'
-      set_check_pass 'no'
-      set_check_fail 'yes'
+    class GitlabConfigUpToDateCheck < SystemCheck::BaseCheck
+      set_name 'GitLab config up to date?'
       set_skip_reason "can't check because of previous errors"
 
       def skip?
@@ -18,7 +16,7 @@ module SystemCheck
 
       def show_error
         try_fixing_it(
-          'Backup your config/gitlab.yml',
+          'Back-up your config/gitlab.yml',
           'Copy config/gitlab.yml.example to config/gitlab.yml',
           'Update config/gitlab.yml to match your setup'
         )
diff --git a/lib/system_check/app/projects_have_namespace_check.rb b/lib/system_check/app/projects_have_namespace_check.rb
index c70633a6d4f..a6ec9f7665c 100644
--- a/lib/system_check/app/projects_have_namespace_check.rb
+++ b/lib/system_check/app/projects_have_namespace_check.rb
@@ -1,7 +1,7 @@
 module SystemCheck
   module App
     class ProjectsHaveNamespaceCheck < SystemCheck::BaseCheck
-      set_name 'projects have namespace: '
+      set_name 'Projects have namespace:'
       set_skip_reason "can't check, you have no projects"
 
       def skip?
diff --git a/lib/system_check/app/ruby_version_check.rb b/lib/system_check/app/ruby_version_check.rb
index 37b4d24aa55..fd82f5f8a4a 100644
--- a/lib/system_check/app/ruby_version_check.rb
+++ b/lib/system_check/app/ruby_version_check.rb
@@ -5,7 +5,7 @@ module SystemCheck
       set_check_pass -> { "yes (#{self.current_version})" }
 
       def self.required_version
-        @required_version ||= Gitlab::VersionInfo.new(2, 1, 0)
+        @required_version ||= Gitlab::VersionInfo.new(2, 3, 3)
       end
 
       def self.current_version
diff --git a/lib/system_check/base_check.rb b/lib/system_check/base_check.rb
index 63b7eea5add..5dcb3f0886b 100644
--- a/lib/system_check/base_check.rb
+++ b/lib/system_check/base_check.rb
@@ -1,10 +1,7 @@
-require 'tasks/gitlab/task_helpers'
-
 module SystemCheck
   # Base class for Checks. You must inherit from here
   # and implement the methods below when necessary
   class BaseCheck
-    include ::Gitlab::TaskHelpers
     include ::SystemCheck::Helpers
 
     # Define a custom term for when check passed
diff --git a/lib/system_check/helpers.rb b/lib/system_check/helpers.rb
index 0a6be42a7d1..cd54baa494f 100644
--- a/lib/system_check/helpers.rb
+++ b/lib/system_check/helpers.rb
@@ -1,5 +1,9 @@
+require 'tasks/gitlab/task_helpers'
+
 module SystemCheck
   module Helpers
+    include ::Gitlab::TaskHelpers
+
     # Display a message telling to fix and rerun the checks
     def fix_and_rerun
       $stdout.puts '  Please fix the error above and rerun the checks.'.color(:red)
@@ -9,8 +13,6 @@ module SystemCheck
     #
     # @param [Array<String>] sources one or more references (documentation or links)
     def for_more_information(*sources)
-      sources = sources.shift if sources.first.is_a?(Array)
-
       $stdout.puts '  For more information see:'.color(:blue)
       sources.each do |source|
         $stdout.puts "  #{source}"
@@ -73,5 +75,12 @@ module SystemCheck
     def sudo_gitlab(command)
       "sudo -u #{gitlab_user} -H #{command}"
     end
+
+    def is_gitlab_user?
+      return @is_gitlab_user unless @is_gitlab_user.nil?
+
+      current_user = run_command(%w(whoami)).chomp
+      @is_gitlab_user = current_user == gitlab_user
+    end
   end
 end
diff --git a/lib/system_check/simple_executor.rb b/lib/system_check/simple_executor.rb
index ad2f549b3fb..c5403693f7a 100644
--- a/lib/system_check/simple_executor.rb
+++ b/lib/system_check/simple_executor.rb
@@ -18,32 +18,32 @@ module SystemCheck
 
     # Executes a single check
     #
-    # @param [SystemCheck::BaseCheck] check
-    def run_check(check)
-      $stdout.print "#{check.display_name} ... "
+    # @param [SystemCheck::BaseCheck] check_klass
+    def run_check(check_klass)
+      $stdout.print "#{check_klass.display_name} ... "
 
-      c = check.new
+      check = check_klass.new
 
       # When implements skip method, we run it first, and if true, skip the check
-      if c.can_skip? && c.skip?
-        $stdout.puts check.skip_reason.color(:magenta)
+      if check.can_skip? && check.skip?
+        $stdout.puts check_klass.skip_reason.color(:magenta)
         return
       end
-      
+
       # When implements a multi check, we don't control the output
-      if c.is_multi_check?
-        c.multi_check
+      if check.is_multi_check?
+        check.multi_check
         return
       end
 
-      if c.check?
-        $stdout.puts check.check_pass.color(:green)
+      if check.check?
+        $stdout.puts check_klass.check_pass.color(:green)
       else
-        $stdout.puts check.check_fail.color(:red)
+        $stdout.puts check_klass.check_fail.color(:red)
 
-        if c.can_repair?
+        if check.can_repair?
           $stdout.print 'Trying to fix error automatically. ...'
-          if c.repair!
+          if check.repair!
             $stdout.puts 'Success'.color(:green)
             return
           else
@@ -51,7 +51,7 @@ module SystemCheck
           end
         end
 
-        c.show_error
+        check.show_error
       end
     end
 
diff --git a/lib/tasks/gitlab/check.rake b/lib/tasks/gitlab/check.rake
index 973517c99dd..63c5e9b9c83 100644
--- a/lib/tasks/gitlab/check.rake
+++ b/lib/tasks/gitlab/check.rake
@@ -21,7 +21,7 @@ namespace :gitlab do
         SystemCheck::App::MigrationsAreUpCheck,
         SystemCheck::App::OrphanedGroupMembersCheck,
         SystemCheck::App::GitlabConfigExistsCheck,
-        SystemCheck::App::GitlabConfigNotOutdatedCheck,
+        SystemCheck::App::GitlabConfigUpToDateCheck,
         SystemCheck::App::LogWritableCheck,
         SystemCheck::App::TmpWritableCheck,
         SystemCheck::App::UploadsDirectoryExistsCheck,
diff --git a/lib/tasks/gitlab/task_helpers.rb b/lib/tasks/gitlab/task_helpers.rb
index e3c9d3b491c..e2307e41be1 100644
--- a/lib/tasks/gitlab/task_helpers.rb
+++ b/lib/tasks/gitlab/task_helpers.rb
@@ -99,16 +99,17 @@ module Gitlab
     end
 
     def warn_user_is_not_gitlab
-      unless @warned_user_not_gitlab
-        gitlab_user = Gitlab.config.gitlab.user
+      return if @warned_user_not_gitlab
+
+      unless is_gitlab_user?
         current_user = run_command(%w(whoami)).chomp
-        unless current_user == gitlab_user
-          puts " Warning ".color(:black).background(:yellow)
-          puts "  You are running as user #{current_user.color(:magenta)}, we hope you know what you are doing."
-          puts "  Things may work\/fail for the wrong reasons."
-          puts "  For correct results you should run this as user #{gitlab_user.color(:magenta)}."
-          puts ""
-        end
+
+        puts " Warning ".color(:black).background(:yellow)
+        puts "  You are running as user #{current_user.color(:magenta)}, we hope you know what you are doing."
+        puts "  Things may work\/fail for the wrong reasons."
+        puts "  For correct results you should run this as user #{gitlab_user.color(:magenta)}."
+        puts ""
+
         @warned_user_not_gitlab = true
       end
     end
diff --git a/spec/lib/system_check/base_executor_spec.rb b/spec/lib/system_check/base_executor_spec.rb
index 139f7f3248f..4b379392da0 100644
--- a/spec/lib/system_check/base_executor_spec.rb
+++ b/spec/lib/system_check/base_executor_spec.rb
@@ -26,7 +26,7 @@ describe SystemCheck::BaseExecutor, lib: true do
       subject << SimpleCheck
     end
 
-    it 'returns an array of classes' do
+    it 'returns a set of classes' do
       expect(subject.checks).to include(SimpleCheck)
     end
   end
@@ -39,12 +39,14 @@ describe SystemCheck::BaseExecutor, lib: true do
     it 'appends a new check to the Set' do
       subject << OtherCheck
       stored_checks = subject.checks.to_a
+
       expect(stored_checks.first).to eq(SimpleCheck)
       expect(stored_checks.last).to eq(OtherCheck)
     end
 
     it 'inserts unique itens only' do
       subject << SimpleCheck
+
       expect(subject.checks.size).to eq(1)
     end
   end

From 23f9e95e8a7dfa3371f0c60a90a4cffc300c0f72 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Tue, 30 May 2017 19:07:06 +0200
Subject: [PATCH 12/14] Changelog

---
 changelogs/unreleased/28080-system-checks.yml | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 changelogs/unreleased/28080-system-checks.yml

diff --git a/changelogs/unreleased/28080-system-checks.yml b/changelogs/unreleased/28080-system-checks.yml
new file mode 100644
index 00000000000..7d83014279a
--- /dev/null
+++ b/changelogs/unreleased/28080-system-checks.yml
@@ -0,0 +1,4 @@
+---
+title: Refactored gitlab:app:check into SystemCheck liberary and improve some checks
+merge_request: 9173
+author:

From d219f9a691973708f70d9517765a2ec926d6d903 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Wed, 31 May 2017 11:32:11 +0200
Subject: [PATCH 13/14] Fix BasicExecutor specs

---
 lib/system_check/helpers.rb      | 11 -----------
 lib/tasks/gitlab/task_helpers.rb | 27 +++++++++++----------------
 spec/lib/system_check_spec.rb    |  4 ----
 3 files changed, 11 insertions(+), 31 deletions(-)

diff --git a/lib/system_check/helpers.rb b/lib/system_check/helpers.rb
index cd54baa494f..c42ae4fe4c4 100644
--- a/lib/system_check/helpers.rb
+++ b/lib/system_check/helpers.rb
@@ -68,19 +68,8 @@ module SystemCheck
       Dir.pwd == '/opt/gitlab/embedded/service/gitlab-rails'
     end
 
-    def gitlab_user
-      Gitlab.config.gitlab.user
-    end
-
     def sudo_gitlab(command)
       "sudo -u #{gitlab_user} -H #{command}"
     end
-
-    def is_gitlab_user?
-      return @is_gitlab_user unless @is_gitlab_user.nil?
-
-      current_user = run_command(%w(whoami)).chomp
-      @is_gitlab_user = current_user == gitlab_user
-    end
   end
 end
diff --git a/lib/tasks/gitlab/task_helpers.rb b/lib/tasks/gitlab/task_helpers.rb
index e2307e41be1..964aa0fe1bc 100644
--- a/lib/tasks/gitlab/task_helpers.rb
+++ b/lib/tasks/gitlab/task_helpers.rb
@@ -98,6 +98,17 @@ module Gitlab
       end
     end
 
+    def gitlab_user
+      Gitlab.config.gitlab.user
+    end
+
+    def is_gitlab_user?
+      return @is_gitlab_user unless @is_gitlab_user.nil?
+
+      current_user = run_command(%w(whoami)).chomp
+      @is_gitlab_user = current_user == gitlab_user
+    end
+
     def warn_user_is_not_gitlab
       return if @warned_user_not_gitlab
 
@@ -114,22 +125,6 @@ module Gitlab
       end
     end
 
-    # Tries to configure git itself
-    #
-    # Returns true if all subcommands were successfull (according to their exit code)
-    # Returns false if any or all subcommands failed.
-    def auto_fix_git_config(options)
-      if !@warned_user_not_gitlab
-        command_success = options.map do |name, value|
-          system(*%W(#{Gitlab.config.git.bin_path} config --global #{name} #{value}))
-        end
-
-        command_success.all?
-      else
-        false
-      end
-    end
-
     def all_repos
       Gitlab.config.repositories.storages.each_value do |repository_storage|
         IO.popen(%W(find #{repository_storage['path']} -mindepth 2 -maxdepth 2 -type d -name *.git)) do |find|
diff --git a/spec/lib/system_check_spec.rb b/spec/lib/system_check_spec.rb
index d2087ad2d83..01679282f87 100644
--- a/spec/lib/system_check_spec.rb
+++ b/spec/lib/system_check_spec.rb
@@ -9,10 +9,6 @@ describe SystemCheck, lib: true do
   end
 
   describe '.run' do
-    it 'requires custom executor to be a BasicExecutor' do
-      expect { subject.run('Component', [], SystemCheck::SimpleExecutor) }.not_to raise_error
-    end
-
     context 'custom matcher' do
       class SimpleCheck < SystemCheck::BaseCheck
         def check?

From 0d4d9a6a63b2ac60ffeeeaef389295919c3119f4 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <brodock@gmail.com>
Date: Wed, 31 May 2017 20:45:00 +0200
Subject: [PATCH 14/14] Refactor and move things around to improve in YAGNI
 perspective

---
 lib/system_check/base_executor.rb             | 24 ---------
 lib/system_check/simple_executor.rb           | 24 ++++++++-
 spec/lib/system_check/base_executor_spec.rb   | 53 -------------------
 spec/lib/system_check/simple_executor_spec.rb | 44 +++++++++++++++
 spec/lib/system_check_spec.rb                 | 42 +++++++--------
 spec/support/matchers/execute_check.rb        |  6 ++-
 6 files changed, 91 insertions(+), 102 deletions(-)
 delete mode 100644 lib/system_check/base_executor.rb
 delete mode 100644 spec/lib/system_check/base_executor_spec.rb

diff --git a/lib/system_check/base_executor.rb b/lib/system_check/base_executor.rb
deleted file mode 100644
index f76f44f3a28..00000000000
--- a/lib/system_check/base_executor.rb
+++ /dev/null
@@ -1,24 +0,0 @@
-module SystemCheck
-  # @attr_reader [Array<BaseCheck>] checks classes of corresponding checks to be executed in the same order
-  # @attr_reader [String] component name of the component relative to the checks being executed
-  class BaseExecutor
-    attr_reader :checks
-    attr_reader :component
-
-    # @param [String] component name of the component relative to the checks being executed
-    def initialize(component)
-      raise ArgumentError unless component.is_a? String
-
-      @component = component
-      @checks = Set.new
-    end
-
-    # Add a check to be executed
-    #
-    # @param [BaseCheck] check class
-    def <<(check)
-      raise ArgumentError unless check < BaseCheck
-      @checks << check
-    end
-  end
-end
diff --git a/lib/system_check/simple_executor.rb b/lib/system_check/simple_executor.rb
index c5403693f7a..dc2d4643a01 100644
--- a/lib/system_check/simple_executor.rb
+++ b/lib/system_check/simple_executor.rb
@@ -4,7 +4,29 @@ module SystemCheck
   #
   # There is no concurrency level and the output is progressively
   # printed into the STDOUT
-  class SimpleExecutor < BaseExecutor
+  #
+  # @attr_reader [Array<BaseCheck>] checks classes of corresponding checks to be executed in the same order
+  # @attr_reader [String] component name of the component relative to the checks being executed
+  class SimpleExecutor
+    attr_reader :checks
+    attr_reader :component
+
+    # @param [String] component name of the component relative to the checks being executed
+    def initialize(component)
+      raise ArgumentError unless component.is_a? String
+
+      @component = component
+      @checks = Set.new
+    end
+
+    # Add a check to be executed
+    #
+    # @param [BaseCheck] check class
+    def <<(check)
+      raise ArgumentError unless check < BaseCheck
+      @checks << check
+    end
+
     # Executes defined checks in the specified order and outputs confirmation or error information
     def execute
       start_checking(component)
diff --git a/spec/lib/system_check/base_executor_spec.rb b/spec/lib/system_check/base_executor_spec.rb
deleted file mode 100644
index 4b379392da0..00000000000
--- a/spec/lib/system_check/base_executor_spec.rb
+++ /dev/null
@@ -1,53 +0,0 @@
-require 'spec_helper'
-
-describe SystemCheck::BaseExecutor, lib: true do
-  class SimpleCheck < SystemCheck::BaseCheck
-    def check?
-      true
-    end
-  end
-
-  class OtherCheck < SystemCheck::BaseCheck
-    def check?
-      false
-    end
-  end
-
-  subject { described_class.new('Test') }
-
-  describe '#component' do
-    it 'returns stored component name' do
-      expect(subject.component).to eq('Test')
-    end
-  end
-
-  describe '#checks' do
-    before do
-      subject << SimpleCheck
-    end
-
-    it 'returns a set of classes' do
-      expect(subject.checks).to include(SimpleCheck)
-    end
-  end
-
-  describe '#<<' do
-    before do
-      subject << SimpleCheck
-    end
-
-    it 'appends a new check to the Set' do
-      subject << OtherCheck
-      stored_checks = subject.checks.to_a
-
-      expect(stored_checks.first).to eq(SimpleCheck)
-      expect(stored_checks.last).to eq(OtherCheck)
-    end
-
-    it 'inserts unique itens only' do
-      subject << SimpleCheck
-
-      expect(subject.checks.size).to eq(1)
-    end
-  end
-end
diff --git a/spec/lib/system_check/simple_executor_spec.rb b/spec/lib/system_check/simple_executor_spec.rb
index f6ba437b71a..a5c6170cd7d 100644
--- a/spec/lib/system_check/simple_executor_spec.rb
+++ b/spec/lib/system_check/simple_executor_spec.rb
@@ -75,6 +75,42 @@ describe SystemCheck::SimpleExecutor, lib: true do
     end
   end
 
+  describe '#component' do
+    it 'returns stored component name' do
+      expect(subject.component).to eq('Test')
+    end
+  end
+
+  describe '#checks' do
+    before do
+      subject << SimpleCheck
+    end
+
+    it 'returns a set of classes' do
+      expect(subject.checks).to include(SimpleCheck)
+    end
+  end
+
+  describe '#<<' do
+    before do
+      subject << SimpleCheck
+    end
+
+    it 'appends a new check to the Set' do
+      subject << OtherCheck
+      stored_checks = subject.checks.to_a
+
+      expect(stored_checks.first).to eq(SimpleCheck)
+      expect(stored_checks.last).to eq(OtherCheck)
+    end
+
+    it 'inserts unique itens only' do
+      subject << SimpleCheck
+
+      expect(subject.checks.size).to eq(1)
+    end
+  end
+
   subject { described_class.new('Test') }
 
   describe '#execute' do
@@ -120,6 +156,7 @@ describe SystemCheck::SimpleExecutor, lib: true do
       context 'when check implements #repair!' do
         it 'executes #repair!' do
           expect_any_instance_of(RepairCheck).to receive(:repair!)
+
           subject.run_check(RepairCheck)
         end
 
@@ -127,6 +164,7 @@ describe SystemCheck::SimpleExecutor, lib: true do
           it 'does not execute #show_error' do
             expect_any_instance_of(RepairCheck).to receive(:repair!).and_call_original
             expect_any_instance_of(RepairCheck).not_to receive(:show_error)
+
             subject.run_check(RepairCheck)
           end
         end
@@ -135,6 +173,7 @@ describe SystemCheck::SimpleExecutor, lib: true do
           it 'does not execute #show_error' do
             expect_any_instance_of(RepairCheck).to receive(:repair!) { false }
             expect_any_instance_of(RepairCheck).to receive(:show_error)
+
             subject.run_check(RepairCheck)
           end
         end
@@ -144,6 +183,7 @@ describe SystemCheck::SimpleExecutor, lib: true do
     context 'when check implements skip?' do
       it 'executes #skip? method' do
         expect_any_instance_of(SkipCheck).to receive(:skip?).and_call_original
+
         subject.run_check(SkipCheck)
       end
 
@@ -153,6 +193,7 @@ describe SystemCheck::SimpleExecutor, lib: true do
 
       it 'does not execute #check when #skip? is true' do
         expect_any_instance_of(SkipCheck).not_to receive(:check?)
+
         subject.run_check(SkipCheck)
       end
     end
@@ -160,17 +201,20 @@ describe SystemCheck::SimpleExecutor, lib: true do
     context 'when implements a #multi_check' do
       it 'executes #multi_check method' do
         expect_any_instance_of(MultiCheck).to receive(:multi_check)
+
         subject.run_check(MultiCheck)
       end
 
       it 'does not execute #check method' do
         expect_any_instance_of(MultiCheck).not_to receive(:check)
+
         subject.run_check(MultiCheck)
       end
 
       context 'when check implements #skip?' do
         it 'executes #skip? method' do
           expect_any_instance_of(SkipMultiCheck).to receive(:skip?).and_call_original
+
           subject.run_check(SkipMultiCheck)
         end
       end
diff --git a/spec/lib/system_check_spec.rb b/spec/lib/system_check_spec.rb
index 01679282f87..23d9beddb08 100644
--- a/spec/lib/system_check_spec.rb
+++ b/spec/lib/system_check_spec.rb
@@ -2,39 +2,35 @@ require 'spec_helper'
 require 'rake_helper'
 
 describe SystemCheck, lib: true do
-  subject { SystemCheck }
+  class SimpleCheck < SystemCheck::BaseCheck
+    def check?
+      true
+    end
+  end
+
+  class OtherCheck < SystemCheck::BaseCheck
+    def check?
+      false
+    end
+  end
 
   before do
     silence_output
   end
 
   describe '.run' do
-    context 'custom matcher' do
-      class SimpleCheck < SystemCheck::BaseCheck
-        def check?
-          true
-        end
-      end
+    subject { SystemCheck }
 
-      class OtherCheck < SystemCheck::BaseCheck
-        def check?
-          false
-        end
-      end
+    it 'detects execution of SimpleCheck' do
+      is_expected.to execute_check(SimpleCheck)
 
-      subject { SystemCheck }
+      subject.run('Test', [SimpleCheck])
+    end
 
-      it 'detects execution of SimpleCheck' do
-        is_expected.to execute_check(SimpleCheck)
+    it 'detects exclusion of OtherCheck in execution' do
+      is_expected.not_to execute_check(OtherCheck)
 
-        SystemCheck.run('Test', [SimpleCheck])
-      end
-
-      it 'detects exclusion of OtherCheck in execution' do
-        is_expected.not_to execute_check(OtherCheck)
-
-        SystemCheck.run('Test', [SimpleCheck])
-      end
+      subject.run('Test', [SimpleCheck])
     end
   end
 end
diff --git a/spec/support/matchers/execute_check.rb b/spec/support/matchers/execute_check.rb
index 9664eb3879d..7232fad52fb 100644
--- a/spec/support/matchers/execute_check.rb
+++ b/spec/support/matchers/execute_check.rb
@@ -14,6 +14,10 @@ RSpec::Matchers.define :execute_check do |expected|
   end
 
   failure_message do |actual|
-    return 'This matcher must be used with SystemCheck' unless actual == SystemCheck
+    'This matcher must be used with SystemCheck' unless actual == SystemCheck
+  end
+
+  failure_message_when_negated do |actual|
+    'This matcher must be used with SystemCheck' unless actual == SystemCheck
   end
 end