GitLab

Created by: amtrack

Most apps today use environment variables for configuration. Background: http://12factor.net/config

Making GitLab and GitLab Shell configurable via environment variables would be a benefit for several use cases:

• Developing GitLab and GitLab Shell (see bkeepers/dotenv)
• Building debian packages (see crohr/pkgr)
• Building docker images (see sameersbn/docker-gitlab)
• PaaS Deployment (see amtrack/buildpack-gitlab)

@crohr, @sameersbn: Currently we're all using sed or patch for patching the config files, right? :-)

• https://github.com/gitlabhq/gitlabhq/blob/master/bin/pkgr_before_precompile.sh#L10-L14
• https://github.com/sameersbn/docker-gitlab/blob/master/assets/init#L340-L342
• https://github.com/amtrack/buildpack-gitlab/blob/master/bin/compile#L66-L67

Let's unite our forces here on GitLab upstream to benefit all!

For backwards compatibility i suggest still supporting config files, but values from environment variables should override values from config files.

For the first, i think the following environment variable would be a good start:

• DATABASE_URL (already implemented in rails > 4.1.0)
• REDIS_URL (right now only if config/resque.yml doesn't exist?)
• GITLAB_URL (should be shared with GitLab Shell)
• GIT_USER (should be shared with GitLab Shell)
• REPOS_PATH (should be shared with GitLab Shell)
• SMTP_URL
• What else?

A simple solution would be to read all config files through ERB, but

• you would still have to copy the example config files to the right location.
• it might be confusing for people who don't use environment variables

A better solution imho would be to implement it in the code directly (maybe here: https://github.com/gitlabhq/gitlabhq/blob/master/config/initializers/1_settings.rb and https://github.com/gitlabhq/gitlab-shell/blob/master/lib/gitlab_config.rb) This would make the overriding of the configuration more streamlined.

Which approach would you prefer? What else has to be done?