Set gitlab.rb in Docker single image in order to make PostgreSQL start up properly

See gitlab-org/omnibus-gitlab#552

docker/single/Dockerfile

@@ -28,6 +28,7 @@ EXPOSE 80 22
 
 # Copy assets
 COPY assets/wrapper /usr/local/bin/
+COPY assets/gitlab.rb /etc/gitlab/
 
 # Wrapper to handle signal, trigger runit and reconfigure GitLab
 CMD ["/usr/local/bin/wrapper"]

docker/single/assets/gitlab.rb

+# External URL should be your Docker instance.
+# By default, GitLab will use the Docker container hostname.
+# Always use port 80 here to force the internal nginx to bind port 80,
+# even if you intend to use another port in Docker.
+# external_url "http://192.168.59.103/"
+
+# Prevent Postgres from trying to allocate 25% of total memory
+postgresql['shared_buffers'] = '1MB'
+
+# Configure GitLab to redirect PostgreSQL logs to the data volume
+postgresql['log_directory'] = '/var/log/gitlab/postgresql'
+
+# Some configuration of GitLab
+# You can find more at https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/README.md#configuration
+gitlab_rails['gitlab_email_from'] = 'gitlab@example.com'
+gitlab_rails['gitlab_support_email'] = 'support@example.com'
+gitlab_rails['time_zone'] = 'Europe/Paris'
+
+# SMTP settings
+# You must use an external server, the Docker container does not install an SMTP server
+gitlab_rails['smtp_enable'] = true
+gitlab_rails['smtp_address'] = "smtp.example.com"
+gitlab_rails['smtp_port'] = 587
+gitlab_rails['smtp_user_name'] = "user"
+gitlab_rails['smtp_password'] = "password"
+gitlab_rails['smtp_domain'] = "example.com"
+gitlab_rails['smtp_authentication'] = "plain"
+gitlab_rails['smtp_enable_starttls_auto'] = true
+
+# Enable LDAP authentication
+# gitlab_rails['ldap_enabled'] = true
+# gitlab_rails['ldap_host'] = 'ldap.example.com'
+# gitlab_rails['ldap_port'] = 389
+# gitlab_rails['ldap_method'] = 'plain' # 'ssl' or 'plain'
+# gitlab_rails['ldap_allow_username_or_email_login'] = false
+# gitlab_rails['ldap_uid'] = 'uid'
+# gitlab_rails['ldap_base'] = 'ou=users,dc=example,dc=com'