Remove references to do_metadata_database (no longer in use)

config/app_config.yml.sample

@@ -823,12 +823,6 @@ development:
     critical: false # either the failure is considered an error or a warning
     timeout: 1 # socket timeout
     trigger_verbose: false
-  do_metadata_database:
-    host: 'localhost'
-    port: 5432
-    database: 'catalog'
-    username: ''
-    password: ''
 
 test:
   <<: *defaults
@@ -864,12 +858,6 @@ test:
     critical: false # either the failure is considered an error or a warning
     timeout: 1 # socket timeout
     trigger_verbose: false
-  do_metadata_database:
-    host: 'localhost'
-    port: 5432
-    database: 'carto_db_test'
-    username: 'postgres'
-    password: ''
 
 staging:
   <<: *defaults

config/app_config.yml.sample.py2

@@ -819,12 +819,6 @@ development:
     critical: false # either the failure is considered an error or a warning
     timeout: 1 # socket timeout
     trigger_verbose: false
-  do_metadata_database:
-    host: 'localhost'
-    port: 5432
-    database: 'catalog'
-    username: ''
-    password: ''
 
 test:
   <<: *defaults
@@ -860,12 +854,6 @@ test:
     critical: false # either the failure is considered an error or a warning
     timeout: 1 # socket timeout
     trigger_verbose: false
-  do_metadata_database:
-    host: 'localhost'
-    port: 5432
-    database: 'carto_db_test'
-    username: 'postgres'
-    password: ''
 
 staging:
   <<: *defaults

lib/carto/db/connection.rb

@@ -43,16 +43,6 @@ module Carto
           end
         end
 
-        def do_metadata_connection()
-          configuration = get_metadata_db_configuration()
-          $pool.fetch(configuration) do
-            get_database_without_search_path(configuration)
-          end
-        rescue StandardError => exception
-          CartoDB::report_exception(exception, "Cannot connect to DO Metadata database")
-          raise exception
-        end
-
         private
 
         def get_database(options, configuration)
@@ -150,18 +140,6 @@ module Carto
           end
         end
 
-        def get_metadata_db_configuration()
-          do_configuration = Cartodb.config[:do_metadata_database]
-          configuration = get_db_configuration_for(do_configuration['host'], do_configuration['database'], {})
-          configuration.merge(do_configuration)
-        end
-
-        def get_database_without_search_path(configuration)
-          resolver = ActiveRecord::ConnectionAdapters::ConnectionSpecification::Resolver.new([])
-          ActiveRecord::Base.connection_handler.establish_connection(
-            get_connection_name(:do_metadata_connection), resolver.spec(configuration)
-          ).connection
-        end
       end
     end
   end

spec/helpers/database_connection_helper.rb

@@ -28,11 +28,4 @@ module DatabaseConnectionHelper
     )
     with_connection options, &block
   end
-
-  def with_do_connection(&block)
-    do_configuration = Cartodb.config[:do_metadata_database].merge(
-      'adapter' => 'postgresql'
-    )
-    with_connection do_configuration, &block
-  end
 end