Remove operations_feature_flags_clients.token column

Related to https://gitlab.com/gitlab-org/gitlab/issues/35697.

db/post_migrate/20191202031812_drop_operations_feature_flags_clients_token.rb

+# frozen_string_literal: true
+
+class DropOperationsFeatureFlagsClientsToken < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    # Ignored in 12.5 - https://gitlab.com/gitlab-org/gitlab/merge_requests/18923
+    remove_column :operations_feature_flags_clients, :token
+  end
+
+  def down
+    unless column_exists?(:operations_feature_flags_clients, :token)
+      add_column :operations_feature_flags_clients, :token, :string # rubocop:disable Migration/AddLimitToStringColumns
+    end
+
+    add_concurrent_index :operations_feature_flags_clients, [:project_id, :token], unique: true,
+      name: 'index_operations_feature_flags_clients_on_project_id_and_token'
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_11_25_140458) do
+ActiveRecord::Schema.define(version: 2019_12_02_031812) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_trgm"
@@ -2776,9 +2776,7 @@ ActiveRecord::Schema.define(version: 2019_11_25_140458) do
 
   create_table "operations_feature_flags_clients", force: :cascade do |t|
     t.integer "project_id", null: false
-    t.string "token"
     t.string "token_encrypted"
-    t.index ["project_id", "token"], name: "index_operations_feature_flags_clients_on_project_id_and_token", unique: true
     t.index ["project_id", "token_encrypted"], name: "index_feature_flags_clients_on_project_id_and_token_encrypted", unique: true
   end
 

ee/changelogs/unreleased/35697-drop-operations-feature-flags-clients-token.yml

+---
+title: Remove operations_feature_flags_clients.token column
+merge_request: 21016
+author:
+type: other