GoCD agent configuration

The app-gocd-agent role maintains a number of scripts that facilitate the deployment process, enabling continuous delivery.

The scripts

All of the scripts are installed /usr/local/ubiquitous/bin:

• ubiquitous-info helps administrators understand the running state of a platform by describing the current configuration. It does so by examining three symbolic links:
  • The active nginx server {} entry in /etc/nginx/sites-enabled.d.
  • The active PHP-FPM pool entry in /etc/php-fpm/pools-enabled.d.
  • The current symlink in the user's home directory.
• ubiquitous-install-release copies new source files into a release directory ready for switching over.
• ubiquitous-set-current-release changes the active release by enabling the inactive FPM pool before altering each of the symbolic links and reloading the services as necessary.

These scripts use a configuration file maintained by the Salt states that describes the platforms installed on the application server. The format of /usr/local/ubiquitous/etc/ubiquitous-platforms is as follows:

<domain>:<basename>:<username>:<home>

Security and sudoers

In order to reload service configuration, the go user must be able to escalate its privileges. The admin state can be used to sudo for passwordless sudo:

sudoers:
  gocd:
    - '%go ALL=(ALL) NOPASSWD: /usr/bin/salt-call ubiquitous_platform.*'

Sample configuration

An example GoCD pipeline configuration for use with the Vagrant environment is provided in the /_vagrant/gocd directory. You can apply this by editing the cruise-config.xml file and restarting the go-server service.