Adds migration to ensure all remote mirror columns get created

changelogs/unreleased/ensure-remote-mirror-columns-in-ce.yml

+---
+title: Fix remote mirror database inconsistencies when upgrading from EE to CE
+merge_request: 19196
+author:
+type: fixed

db/migrate/20180529093006_ensure_remote_mirror_columns.rb

+class EnsureRemoteMirrorColumns < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_column :remote_mirrors, :last_update_started_at, :datetime unless column_exists?(:remote_mirrors, :last_update_started_at)
+    add_column :remote_mirrors, :remote_name, :string unless column_exists?(:remote_mirrors, :remote_name)
+
+    unless column_exists?(:remote_mirrors, :only_protected_branches)
+      add_column_with_default(:remote_mirrors,
+                              :only_protected_branches,
+                              :boolean,
+                              default: false,
+                              allow_null: false)
+    end
+  end
+
+  def down
+    # db/migrate/20180503131624_create_remote_mirrors.rb will remove the table
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180524132016) do
+ActiveRecord::Schema.define(version: 20180529093006) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"