Thanks Robert for the corrections in the environment variables docs.

config/database.yml.env

 <%= ENV['RAILS_ENV'] %>:
-  adapter: <%= ENV['GITLAB_DATABASE_ADAPTER'] || 'postgresql'' %>
+  adapter: <%= ENV['GITLAB_DATABASE_ADAPTER'] || 'postgresql' %>
   encoding: <%= ENV['GITLAB_DATABASE_ENCODING'] || 'unicode' %>
   database: <%= ENV['GITLAB_DATABASE_DATABASE'] || "gitlab_#{ENV['RAILS_ENV']}" %>
   pool: <%= ENV['GITLAB_DATABASE_POOL'] || '10' %>

doc/administration/enviroment_variables.md

@@ -26,7 +26,7 @@ As explained in the [Heroku documentation](https://devcenter.heroku.com/articles
 - host
 - port
-To do set these please `cp config/database.yml.rb config/database.yml` and use the following variables:
+To do so please `cp config/database.yml.env config/database.yml` and use the following variables:
 Variable | Default
 --- | ---