Move min schema version check to db:migrate

Rather than have it checked only as part of gitlab:db:configure, we will
instead have it as a pre-req for every db:migrate command

changelogs/unreleased/check-min-schema-migrate.yml

@@ -1,5 +1,5 @@
 ---
 title: Added a min schema version check to gitlab:db:configure
-merge_request:
+merge_request: 29882
 author:
 type: added

lib/gitlab/database.rb

@@ -14,6 +14,7 @@ module Gitlab
     # Minimum schema version from which migrations are be supported
     # Migrations before this version may have been removed
     MIN_SCHEMA_VERSION = 20190506135400
+    MIN_SCHEMA_GITLAB_VERSION = '11.11.0'
 
     def self.config
       ActiveRecord::Base.configurations[Rails.env]

lib/tasks/gitlab/db.rake

@@ -53,10 +53,6 @@ namespace :gitlab do
       # Check if we have existing db tables
       # The schema_migrations table will still exist if drop_tables was called
       if ActiveRecord::Base.connection.tables.count > 1
-        if ActiveRecord::Migrator.current_version < Gitlab::Database::MIN_SCHEMA_VERSION
-          raise "Your current database version is too old to be migrated. Please see https://docs.gitlab.com/ee/policy/maintenance.html#upgrade-recommendations"
-        end
-
         Rake::Task['db:migrate'].invoke
       else
         # Add post-migrate paths to ensure we mark all migrations as up

lib/tasks/migrate/schema_check.rake

@@ -0,0 +1,11 @@
+desc 'Configures the database by running migrate, or by loading the schema and seeding if needed'
+task schema_version_check: :environment do
+  if ActiveRecord::Migrator.current_version < Gitlab::Database::MIN_SCHEMA_VERSION
+    raise "Your current database version is too old to be migrated. " \
+          "You should upgrade to GitLab #{Gitlab::Database::MIN_SCHEMA_GITLAB_VERSION} before moving to this version. " \
+          "Please see https://docs.gitlab.com/ee/policy/maintenance.html#upgrade-recommendations"
+  end
+end
+
+# Ensure the check is a pre-requisite when running db:migrate
+Rake::Task["db:migrate"].enhance [:schema_version_check]

spec/tasks/gitlab/db_rake_spec.rb

@@ -31,7 +31,7 @@ describe 'gitlab:db namespace rake task' do
     it 'raises an when schema has been loaded, but version is too old to migrate' do
       allow(ActiveRecord::Base.connection).to receive(:tables).and_return(%w[table1 table2])
       allow(ActiveRecord::Migrator).to receive(:current_version).and_return(25)
-      expect { run_rake_task('gitlab:db:configure') }.to raise_error(RuntimeErrorm, /current database version is too old to be migrated/)
+      expect { run_rake_task('gitlab:db:configure') }.to raise_error(RuntimeError, /current database version is too old to be migrated/)
     end
 
     it 'invokes db:shema:load and db:seed_fu when schema is not loaded' do

spec/tasks/migrate/schema_check_rake_spec.rb

@@ -0,0 +1,27 @@
+require 'spec_helper'
+require 'rake'
+
+describe 'schema_version_check rake task' do
+  before :all do
+    Rake.application.rake_require 'active_record/railties/databases'
+
+    # empty task as env is already loaded
+    Rake::Task.define_task :environment
+  end
+
+  before do
+    # Stub out db tasks
+    allow(ActiveRecord::Tasks::DatabaseTasks).to receive(:migrate).and_return(true)
+    allow(ActiveRecord::Migrator).to receive(:current_version).and_return(Gitlab::Database::MIN_SCHEMA_VERSION)
+  end
+
+  it 'raises an error when schema version is too old to migrate' do
+    allow(ActiveRecord::Migrator).to receive(:current_version).and_return(25)
+    expect { run_rake_task('db:migrate') }.to raise_error(RuntimeError, /current database version is too old to be migrated/)
+  end
+
+  def run_rake_task(task_name)
+    Rake::Task[task_name].reenable
+    Rake.application.invoke_task task_name
+  end
+end