Make CreateGeoNodeNamespaceLinks migration simpler

db/migrate/20170717213940_create_geo_node_namespace_links.rb

@@ -5,26 +5,14 @@ class CreateGeoNodeNamespaceLinks < ActiveRecord::Migration
 
   disable_ddl_transaction!
 
-  def up
+  def change
     create_table :geo_node_namespace_links do |t|
       t.references :geo_node, index: true, foreign_key: { on_delete: :cascade }, null: false
-      t.integer :namespace_id, null: false
-    end
-
-    add_timestamps_with_timezone :geo_node_namespace_links
-
-    add_concurrent_foreign_key :geo_node_namespace_links, :namespaces, column: :namespace_id, on_delete: :cascade
+      t.references :namespace, foreign_key: { on_delete: :cascade }, null: false
 
-    add_concurrent_index :geo_node_namespace_links, [:geo_node_id, :namespace_id], unique: true
+      t.index [:geo_node_id, :namespace_id], unique: true
     end
 
-  def down
-    remove_foreign_key :geo_node_namespace_links, column: :namespace_id
-
-    if index_exists?(:geo_node_namespace_links, [:geo_node_id, :namespace_id])
-      remove_concurrent_index :geo_node_namespace_links, [:geo_node_id, :namespace_id]
-    end
-
-    drop_table :geo_node_namespace_links
+    add_timestamps_with_timezone :geo_node_namespace_links
   end
 end

db/schema.rb

@@ -1993,7 +1993,7 @@ ActiveRecord::Schema.define(version: 20170803130232) do
   add_foreign_key "geo_event_log", "geo_repository_renamed_events", column: "repository_renamed_event_id", name: "fk_86c84214ec", on_delete: :cascade
   add_foreign_key "geo_event_log", "geo_repository_updated_events", column: "repository_updated_event_id", on_delete: :cascade
   add_foreign_key "geo_node_namespace_links", "geo_nodes", on_delete: :cascade
-  add_foreign_key "geo_node_namespace_links", "namespaces", name: "fk_41ff5fb854", on_delete: :cascade
+  add_foreign_key "geo_node_namespace_links", "namespaces", on_delete: :cascade
   add_foreign_key "geo_repositories_changed_events", "geo_nodes", on_delete: :cascade
   add_foreign_key "geo_repository_renamed_events", "projects", on_delete: :cascade
   add_foreign_key "geo_repository_updated_events", "projects", on_delete: :cascade