From b1c8d342bfd9fc46189b3f6ec0ee37828b8a751d Mon Sep 17 00:00:00 2001
From: Maciek Dubinski <maciek@dubinski.net>
Date: Fri, 20 May 2016 19:03:31 +0200
Subject: [PATCH] Servers sub task for doctor.

---
 CHANGELOG.md                                  |   1 +
 lib/capistrano/configuration.rb               |   8 +-
 lib/capistrano/configuration/server.rb        |   4 +
 lib/capistrano/doctor.rb                      |   1 +
 lib/capistrano/doctor/servers_doctor.rb       | 105 ++++++++++++++++++
 lib/capistrano/tasks/doctor.rake              |   7 +-
 .../capistrano/doctor/servers_doctor_spec.rb  |  85 ++++++++++++++
 7 files changed, 206 insertions(+), 5 deletions(-)
 create mode 100644 lib/capistrano/doctor/servers_doctor.rb
 create mode 100644 spec/lib/capistrano/doctor/servers_doctor_spec.rb

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 321f789a..cd6c2408 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ Reverse Chronological Order:
 
 https://github.com/capistrano/capistrano/compare/v3.5.0...HEAD
 
+  * Added a `doctor:servers` subtask that outputs a summary of servers, roles & properties (@irvingwashington)
   * Raise a better error when an ‘after’ hook isn’t found (@jdelStrother)
   * Restrict the uploaded git wrapper script permissions to 700 (@irvingwashington)
   * Make path to git wrapper script configurable (@thickpaddy)
diff --git a/lib/capistrano/configuration.rb b/lib/capistrano/configuration.rb
index fef90938..b88ce537 100644
--- a/lib/capistrano/configuration.rb
+++ b/lib/capistrano/configuration.rb
@@ -133,16 +133,16 @@ module Capistrano
       installer.install(plugin, load_hooks: load_hooks)
     end
 
+    def servers
+      @servers ||= Servers.new
+    end
+
     private
 
     def cmdline_filters
       @cmdline_filters ||= []
     end
 
-    def servers
-      @servers ||= Servers.new
-    end
-
     def installer
       @installer ||= PluginInstaller.new
     end
diff --git a/lib/capistrano/configuration/server.rb b/lib/capistrano/configuration/server.rb
index ca5f1547..bf7da8df 100644
--- a/lib/capistrano/configuration/server.rb
+++ b/lib/capistrano/configuration/server.rb
@@ -119,6 +119,10 @@ module Capistrano
           end
         end
 
+        def to_h
+          @properties
+        end
+
         private
 
         def lvalue(key)
diff --git a/lib/capistrano/doctor.rb b/lib/capistrano/doctor.rb
index f38af290..4fa42398 100644
--- a/lib/capistrano/doctor.rb
+++ b/lib/capistrano/doctor.rb
@@ -1,5 +1,6 @@
 require "capistrano/doctor/environment_doctor"
 require "capistrano/doctor/gems_doctor"
 require "capistrano/doctor/variables_doctor"
+require "capistrano/doctor/servers_doctor"
 
 load File.expand_path("../tasks/doctor.rake", __FILE__)
diff --git a/lib/capistrano/doctor/servers_doctor.rb b/lib/capistrano/doctor/servers_doctor.rb
new file mode 100644
index 00000000..645c18c1
--- /dev/null
+++ b/lib/capistrano/doctor/servers_doctor.rb
@@ -0,0 +1,105 @@
+require "capistrano/doctor/output_helpers"
+
+module Capistrano
+  module Doctor
+    class ServersDoctor
+      include Capistrano::Doctor::OutputHelpers
+
+      def initialize(env=Capistrano::Configuration.env)
+        @servers = env.servers.to_a
+      end
+
+      def call
+        title("Servers (#{servers.size})")
+        rwc = RoleWhitespaceChecker.new(servers)
+
+        table(servers) do |server, row|
+          sd = ServerDecorator.new(server)
+
+          row << sd.uri_form
+          row << sd.roles
+          row << sd.properties
+          row.yellow if rwc.any_has_whitespace?(server.roles)
+        end
+
+        if rwc.whitespace_roles.any?
+          warning "\nWhitespace detected in role(s) #{rwc.whitespace_roles_decorated}. " \
+            "This might be a result of a mistyped \"%w()\" array literal."
+        end
+        puts
+      end
+
+      private
+
+      attr_reader :servers
+
+      class RoleWhitespaceChecker
+        attr_reader :whitespace_roles, :servers
+
+        def initialize(servers)
+          @servers = servers
+          @whitespace_roles = find_whitespace_roles
+        end
+
+        def any_has_whitespace?(roles)
+          roles.any? { |role| include_whitespace?(role) }
+        end
+
+        def include_whitespace?(role)
+          role =~ /\s/
+        end
+
+        def whitespace_roles_decorated
+          whitespace_roles.map(&:inspect).join(", ")
+        end
+
+        private
+
+        def find_whitespace_roles
+          servers.map(&:roles).map(&:to_a).flatten.uniq
+                 .select { |role| include_whitespace?(role) }
+        end
+      end
+
+      class ServerDecorator
+        def initialize(server)
+          @server = server
+        end
+
+        def uri_form
+          [
+            server.user,
+            server.user && "@",
+            server.hostname,
+            server.port && ":",
+            server.port
+          ].compact.join
+        end
+
+        def roles
+          server.roles.to_a.inspect
+        end
+
+        def properties
+          return "" unless server.properties.keys.any?
+          pretty_inspect(server.properties.to_h)
+        end
+
+        private
+
+        attr_reader :server
+
+        # Hashes with proper padding
+        def pretty_inspect(element)
+          return element.inspect unless element.is_a?(Hash)
+
+          pairs_string = element.keys.map do |key|
+            [pretty_inspect(key), pretty_inspect(element.fetch(key))].join(" => ")
+          end.join(", ")
+
+          "{ #{pairs_string} }"
+        end
+      end
+    end
+  end
+end
diff --git a/lib/capistrano/tasks/doctor.rake b/lib/capistrano/tasks/doctor.rake
index dbddff48..e588a2e9 100644
--- a/lib/capistrano/tasks/doctor.rake
+++ b/lib/capistrano/tasks/doctor.rake
@@ -1,5 +1,5 @@
 desc "Display a Capistrano troubleshooting report (all doctor: tasks)"
-task doctor: ["doctor:environment", "doctor:gems", "doctor:variables"]
+task doctor: ["doctor:environment", "doctor:gems", "doctor:variables", "doctor:servers"]
 
 namespace :doctor do
   desc "Display Ruby environment details"
@@ -16,4 +16,9 @@ namespace :doctor do
   task :variables do
     Capistrano::Doctor::VariablesDoctor.new.call
   end
+
+  desc "Display the effective servers configuration"
+  task :servers do
+    Capistrano::Doctor::ServersDoctor.new.call
+  end
 end
diff --git a/spec/lib/capistrano/doctor/servers_doctor_spec.rb b/spec/lib/capistrano/doctor/servers_doctor_spec.rb
new file mode 100644
index 00000000..474ce0e0
--- /dev/null
+++ b/spec/lib/capistrano/doctor/servers_doctor_spec.rb
@@ -0,0 +1,85 @@
+require "spec_helper"
+require "capistrano/doctor/servers_doctor"
+
+module Capistrano
+  module Doctor
+    describe ServersDoctor do
+      include Capistrano::DSL
+      let(:doc) { ServersDoctor.new }
+
+      after { Capistrano::Configuration.reset! }
+
+      it "prints using 4-space indentation" do
+        expect { doc.call }.to output(/^ {4}/).to_stdout
+      end
+
+      it "prints the number of defined servers" do
+        role :app, %w(example.com)
+        server "www@example.com:22"
+
+        expect { doc.call }.to output(/Servers \(2\)/).to_stdout
+      end
+
+      describe "prints the server's details" do
+        it "including username" do
+          server "www@example.com"
+          expect { doc.call }.to output(/www@example.com/).to_stdout
+        end
+
+        it "including port" do
+          server "www@example.com:22"
+          expect { doc.call }.to output(/www@example.com:22/).to_stdout
+        end
+
+        it "including roles" do
+          role :app, %w(example.com)
+          expect { doc.call }.to output(/example.com\s+\[:app\]/).to_stdout
+        end
+
+        it "including empty roles" do
+          server "example.com"
+          expect { doc.call }.to output(/example.com\s+\[\]/).to_stdout
+        end
+
+        it "including properties" do
+          server "example.com", roles: %w(app db), primary: true
+          expect { doc.call }.to \
+            output(/example.com\s+\[:app, :db\]\s+\{ :primary => true \}/).to_stdout
+        end
+
+        it "including misleading role name alert" do
+          server "example.com", roles: ["web app db"]
+          warning_msg = 'Whitespace detected in role(s) :"web app db". ' \
+            'This might be a result of a mistyped "%w()" array literal'
+
+          expect { doc.call }.to output(/#{Regexp.escape(warning_msg)}/).to_stdout
+        end
+      end
+
+      it "doesn't fail for no servers" do
+        expect { doc.call }.to output("\nServers (0)\n    \n").to_stdout
+      end
+
+      describe "Rake" do
+        before do
+          load File.expand_path("../../../../../lib/capistrano/doctor.rb",
+                                __FILE__)
+        end
+
+        after do
+          Rake::Task.clear
+        end
+
+        it "has an doctor:servers task that calls ServersDoctor" do
+          ServersDoctor.any_instance.expects(:call)
+          Rake::Task["doctor:servers"].invoke
+        end
+
+        it "has a doctor task that depends on doctor:servers" do
+          expect(Rake::Task["doctor"].prerequisites).to \
+            include("doctor:servers")
+        end
+      end
+    end
+  end
+end