Merge branch 'enable_pg_trgm_with_before_run' into 'master'

Chef 12.6 introduced :before, use it to enable extension before migration or database seed.

With gitlab-org/omnibus-gitlab!704 , Chef got upgraded to 12.6.

That version has a new feature to run a notification before resource is ran.

Use this feature to resolve gitlab-org/omnibus-gitlab#1189 
.(and similar)

See merge request !705

files/gitlab-cookbooks/gitlab/definitions/migrate_database.rb

@@ -26,6 +26,7 @@ define :migrate_database, :command => nil, :action => :run, :restarts => [] do
       exit ${PIPESTATUS[0]}
     EOH
     action params[:action]
+    notifies :run, 'execute[enable pg_trgm extension]', :before unless OmnibusHelper.not_listening?("posgresql") || !node['gitlab']['postgresql']['enable']
     notifies :run, "execute[clear the #{params[:name]} cache]", :immediately unless OmnibusHelper.not_listening?("redis")
     params[:restarts].each do |svc|
       notifies :restart, svc, :immediately

files/gitlab-cookbooks/gitlab/recipes/database_migrations.rb

@@ -25,6 +25,7 @@ execute "initialize gitlab-rails database" do
   command "/opt/gitlab/bin/gitlab-rake db:schema:load db:seed_fu"
   environment ({'GITLAB_ROOT_PASSWORD' => initial_root_password }) if initial_root_password
   action :nothing
+  notifies :run, 'execute[enable pg_trgm extension]', :before unless OmnibusHelper.not_listening?("posgresql") || !node['gitlab']['postgresql']['enable']
 end
 
 migrate_database 'gitlab-rails' do

files/gitlab-cookbooks/gitlab/recipes/gitlab-rails.rb

@@ -289,7 +289,6 @@ end
 # Only run `rake db:migrate` when the gitlab-rails version has changed
 remote_file File.join(gitlab_rails_dir, 'VERSION') do
   source "file:///opt/gitlab/embedded/service/gitlab-rails/VERSION"
-  notifies :run, 'execute[enable pg_trgm extension]', :immediately unless postgresql_not_listening || !node['gitlab']['postgresql']['enable']
   notifies :run, 'bash[migrate gitlab-rails database]' unless postgresql_not_listening
   notifies :run, 'execute[clear the gitlab-rails cache]' unless redis_not_listening
   notifies :run, 'bash[generate assets]' if node['gitlab']['gitlab-rails']['gitlab_relative_url']

files/gitlab-cookbooks/gitlab/recipes/postgresql.rb

@@ -154,7 +154,6 @@ if node['gitlab']['gitlab-rails']['enable']
     command "#{bin_dir}/createdb --port #{pg_port} -h #{postgresql_socket_dir} -O #{gitlab_sql_user} #{database_name}"
     user postgresql_user
     retries 30
-    notifies :run, "execute[enable pg_trgm extension]", :immediately
     notifies :run, "execute[initialize gitlab-rails database]", :immediately
     not_if { !pg_helper.is_running? || pg_helper.database_exists?(database_name) }
   end