Check supported version when migrating

Set the mininum supported migration version to be the schema version as
of 11.11.0, and errors you if that is not detected during
gitlab:db:configure

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

+---
+title: Added a min schema version check to gitlab:db:configure
+merge_request:
+author:
+type: added

doc/update/upgrading_from_source.md

@@ -324,7 +324,7 @@ sudo -u git -H bundle install --deployment --without development test mysql aws
 sudo -u git -H bundle clean
 
 # Run database migrations
-sudo -u git -H bundle exec rake db:migrate RAILS_ENV=production
+sudo -u git -H bundle exec rake gitlab:db:configure RAILS_ENV=production
 
 # Compile GetText PO files
 

lib/gitlab/database.rb

@@ -11,6 +11,10 @@ module Gitlab
     # https://dev.mysql.com/doc/refman/5.7/en/datetime.html
     MAX_TIMESTAMP_VALUE = Time.at((1 << 31) - 1).freeze
 
+    # Minimum schema version from which migrations are be supported
+    # Migrations before this version may have been removed
+    MIN_SCHEMA_VERSION = 20190506135400
+
     def self.config
       ActiveRecord::Base.configurations[Rails.env]
     end

lib/tasks/gitlab/db.rake

@@ -53,6 +53,10 @@ 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

spec/tasks/gitlab/db_rake_spec.rb

@@ -16,6 +16,7 @@ describe 'gitlab:db namespace rake task' do
     allow(Rake::Task['db:migrate']).to receive(:invoke).and_return(true)
     allow(Rake::Task['db:schema:load']).to receive(:invoke).and_return(true)
     allow(Rake::Task['db:seed_fu']).to receive(:invoke).and_return(true)
+    allow(ActiveRecord::Migrator).to receive(:current_version).and_return(Gitlab::Database::MIN_SCHEMA_VERSION)
   end
 
   describe 'configure' do
@@ -27,6 +28,12 @@ describe 'gitlab:db namespace rake task' do
       expect { run_rake_task('gitlab:db:configure') }.not_to raise_error
     end
 
+    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/)
+    end
+
     it 'invokes db:shema:load and db:seed_fu when schema is not loaded' do
       allow(ActiveRecord::Base.connection).to receive(:tables).and_return([])
       expect(Rake::Task['db:schema:load']).to receive(:invoke)