Drop FK firstrevert-4ff91723

1 files changed, 37 insertions, 0 deletions

diff --git a/db/migrate/20181031190558_drop_fk_gcp_clusters_table.rb b/db/migrate/20181031190558_drop_fk_gcp_clusters_table.rb
new file mode 100644
index 00000000000..a7106111f46
--- /dev/null
+++ b/db/migrate/20181031190558_drop_fk_gcp_clusters_table.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+class DropFkGcpClustersTable < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    remove_foreign_key_if_exists :gcp_clusters, column: :project_id
+    remove_foreign_key_if_exists :gcp_clusters, column: :user_id
+    remove_foreign_key_if_exists :gcp_clusters, column: :service_id
+  end
+
+  def down
+    add_foreign_key_if_not_exists :gcp_clusters, :projects, column: :project_id, on_delete: :cascade
+    add_foreign_key_if_not_exists :gcp_clusters, :users, column: :user_id, on_delete: :nullify
+    add_foreign_key_if_not_exists :gcp_clusters, :services, column: :service_id, on_delete: :nullify
+  end
+
+  private
+
+  def add_foreign_key_if_not_exists(source, target, column:, on_delete:)
+    return unless table_exists?(source)
+    return if foreign_key_exists?(source, target, column: column)
+
+    add_concurrent_foreign_key(source, target, column: column, on_delete: on_delete)
+  end
+
+  def remove_foreign_key_if_exists(table, column:)
+    return unless table_exists?(table)
+    return unless foreign_key_exists?(table, column: column)
+
+    remove_foreign_key(table, column: column)
+  end
+end