Enable pgbouncer application_name_add_host config by default

This setting makes it easier to debug which application is connecting
to pgbouncer. We've had it enabled on GitLab.com for a while.

Closes #2415

files/gitlab-config-template/gitlab.rb.template

@@ -1533,6 +1533,7 @@ external_url 'GENERATED_EXTERNAL_URL'
 # pgbouncer['listen_port'] = '6432'
 # pgbouncer['pool_mode'] = 'session'
 # pgbouncer['server_reset_query'] = 'DISCARD ALL'
+# pgbouncer['application_name_add_host'] = '1'
 # pgbouncer['max_client_conn'] = '100'
 # pgbouncer['default_pool_size'] = '20'
 # pgbouncer['min_pool_size'] = '0'

files/gitlab-cookbooks/gitlab-ee/attributes/default.rb

@@ -141,6 +141,7 @@ default['gitlab']['pgbouncer']['listen_port'] = 6432
 default['gitlab']['pgbouncer']['pool_mode'] = 'session'
 default['gitlab']['pgbouncer']['server_reset_query'] = 'DISCARD ALL'
 default['gitlab']['pgbouncer']['max_client_conn'] = 100
+default['gitlab']['pgbouncer']['application_name_add_host'] = 1
 default['gitlab']['pgbouncer']['default_pool_size'] = 20
 default['gitlab']['pgbouncer']['min_pool_size'] = 0
 default['gitlab']['pgbouncer']['reserve_pool_size'] = 0

files/gitlab-cookbooks/gitlab-ee/templates/default/pgbouncer.ini.erb

@@ -166,7 +166,7 @@ ignore_startup_parameters = <%= @ignore_startup_parameters %>
 ;server_check_delay = 30
 
 ;; Use <appname - host> as application_name on server.
-;application_name_add_host = 0
+application_name_add_host = <%= @application_name_add_host %>
 
 ;;;
 ;;; Connection limits

spec/chef/gitlab-ee/recipes/pgbouncer_spec.rb

@@ -67,6 +67,7 @@ describe 'gitlab-ee::pgbouncer' do
         expect(content).to match(/^listen_port = 6432$/)
         expect(content).to match(/^pool_mode = session$/)
         expect(content).to match(/^server_reset_query = DISCARD ALL$/)
+        expect(content).to match(/^application_name_add_host = 1$/)
         expect(content).to match(/^max_client_conn = 100$/)
         expect(content).to match(/^default_pool_size = 20$/)
         expect(content).to match(/^min_pool_size = 0$/)