Merge branch 'drop_db_before_restore' into 'master'

Reload the schema before restoring a database backup

If a user tries to downgrade and restore after a failed upgrade,
the database may still contain newer tables. Reload the older
schema before restoring the database to avoid future upgrade
problems. Also, add a rake task to help users add migration
versions to the database so it's easier to recover from these
errors if they do occur. Fixes #13419

See merge request !2807

2 files changed, 61 insertions, 8 deletions

diff --git a/lib/tasks/gitlab/backup.rake b/lib/tasks/gitlab/backup.rake
index cb4abe13799..402bb338f27 100644
--- a/lib/tasks/gitlab/backup.rake
+++ b/lib/tasks/gitlab/backup.rake
@@ -22,7 +22,7 @@ namespace :gitlab do
     end
 
     # Restore backup of GitLab system
-    desc "GitLab | Restore a previously created backup"
+    desc 'GitLab | Restore a previously created backup'
     task restore: :environment do
       warn_user_is_not_gitlab
       configure_cron_mode
@@ -30,13 +30,31 @@ namespace :gitlab do
       backup = Backup::Manager.new
       backup.unpack
 
-      Rake::Task["gitlab:backup:db:restore"].invoke unless backup.skipped?("db")
-      Rake::Task["gitlab:backup:repo:restore"].invoke unless backup.skipped?("repositories")
-      Rake::Task["gitlab:backup:uploads:restore"].invoke unless backup.skipped?("uploads")
-      Rake::Task["gitlab:backup:builds:restore"].invoke unless backup.skipped?("builds")
-      Rake::Task["gitlab:backup:artifacts:restore"].invoke unless backup.skipped?("artifacts")
-      Rake::Task["gitlab:backup:lfs:restore"].invoke unless backup.skipped?("lfs")
-      Rake::Task["gitlab:shell:setup"].invoke
+      unless backup.skipped?('db')
+        unless ENV['force'] == 'yes'
+          warning = warning = <<-MSG.strip_heredoc
+            Before restoring the database we recommend removing all existing
+            tables to avoid future upgrade problems. Be aware that if you have
+            custom tables in the GitLab database these tables and all data will be
+            removed.
+          MSG
+          ask_to_continue
+          puts 'Removing all tables. Press `Ctrl-C` within 5 seconds to abort'.yellow
+          sleep(5)
+        end
+        # Drop all tables Load the schema to ensure we don't have any newer tables
+        # hanging out from a failed upgrade
+        $progress.puts 'Cleaning the database ... '.blue
+        Rake::Task['gitlab:db:drop_tables'].invoke
+        $progress.puts 'done'.green
+        Rake::Task['gitlab:backup:db:restore'].invoke
+      end
+      Rake::Task['gitlab:backup:repo:restore'].invoke unless backup.skipped?('repositories')
+      Rake::Task['gitlab:backup:uploads:restore'].invoke unless backup.skipped?('uploads')
+      Rake::Task['gitlab:backup:builds:restore'].invoke unless backup.skipped?('builds')
+      Rake::Task['gitlab:backup:artifacts:restore'].invoke unless backup.skipped?('artifacts')
+      Rake::Task['gitlab:backup:lfs:restore'].invoke unless backup.skipped?('lfs')
+      Rake::Task['gitlab:shell:setup'].invoke
 
       backup.cleanup
     end
diff --git a/lib/tasks/gitlab/db.rake b/lib/tasks/gitlab/db.rake
new file mode 100644
index 00000000000..4921c6e0bcf
--- /dev/null
+++ b/lib/tasks/gitlab/db.rake
@@ -0,0 +1,35 @@
+namespace :gitlab do
+  namespace :db do
+    desc 'GitLab | Manually insert schema migration version'
+    task :mark_migration_complete, [:version] => :environment do |_, args|
+      unless args[:version]
+        puts "Must specify a migration version as an argument".red
+        exit 1
+      end
+
+      version = args[:version].to_i
+      if version == 0
+        puts "Version '#{args[:version]}' must be a non-zero integer".red
+        exit 1
+      end
+
+      sql = "INSERT INTO schema_migrations (version) VALUES (#{version})"
+      begin
+        ActiveRecord::Base.connection.execute(sql)
+        puts "Successfully marked '#{version}' as complete".green
+      rescue ActiveRecord::RecordNotUnique
+        puts "Migration version '#{version}' is already marked complete".yellow
+      end
+    end
+
+    desc 'Drop all tables'
+    task :drop_tables => :environment do
+      connection = ActiveRecord::Base.connection
+      tables = connection.tables
+      tables.delete 'schema_migrations'
+      # Truncate schema_migrations to ensure migrations re-run
+      connection.execute('TRUNCATE schema_migrations')
+      tables.each { |t| connection.execute("DROP TABLE #{t}") }
+    end
+  end
+end