Move ChatOps migrations to Core

ee/db/migrate/20180209115333_create_chatops_tables.rb → db/migrate/20180209115333_create_chatops_tables.rb

-# See http://doc.gitlab.com/ce/development/migration_style_guide.html
-# for more information on how to write migrations for GitLab.
+# frozen_string_literal: true
 
 class CreateChatopsTables < ActiveRecord::Migration[4.2]
   include Gitlab::Database::MigrationHelpers
 
-  # Set this constant to true if this migration requires downtime.
   DOWNTIME = false
 
   def change
@@ -16,6 +14,8 @@ class CreateChatopsTables < ActiveRecord::Migration[4.2]
       # A pipeline can only contain one row in this table, hence this index is
       # unique.
       t.index :pipeline_id, unique: true
+
+      t.index :chat_name_id
     end
 
     # rubocop:disable Migration/AddConcurrentForeignKey

ee/db/migrate/20181105122803_add_missing_indexes_for_foreign_keys_ee.rb

@@ -12,7 +12,11 @@ class AddMissingIndexesForForeignKeysEE < ActiveRecord::Migration[4.2]
     add_concurrent_index(:application_settings, :custom_project_templates_group_id)
     add_concurrent_index(:board_assignees, :assignee_id)
     add_concurrent_index(:board_labels, :label_id)
-    add_concurrent_index(:ci_pipeline_chat_data, :chat_name_id)
+
+    # This index has been hoisted up to `20180209115333_create_chatops_tables.rb`
+    # so that it could be ported to Core without breaking upgrades
+    add_concurrent_index(:ci_pipeline_chat_data, :chat_name_id) unless index_exists?(:ci_pipeline_chat_data, :chat_name_id)
+
     add_concurrent_index(:geo_node_namespace_links, :namespace_id)
     add_concurrent_index(:namespaces, :file_template_project_id)
     add_concurrent_index(:protected_branch_merge_access_levels, :group_id)
@@ -29,7 +33,6 @@ class AddMissingIndexesForForeignKeysEE < ActiveRecord::Migration[4.2]
     remove_concurrent_index(:application_settings, :custom_project_templates_group_id)
     remove_concurrent_index(:board_assignees, :assignee_id)
     remove_concurrent_index(:board_labels, :label_id)
-    remove_concurrent_index(:ci_pipeline_chat_data, :chat_name_id)
     remove_concurrent_index(:geo_node_namespace_links, :namespace_id)
     remove_concurrent_index(:namespaces, :file_template_project_id)
     remove_concurrent_index(:protected_branch_merge_access_levels, :group_id)