Varnish (Webproxy)

This role provides Varnish.

How we differ from what you are used to

Here is how we differ from what you already know from common Linux distributions and how you are used to configure, start, stop and maintain these packages.

• configuration file locations:

  Since we use NixOS, configuration files have to be edited in /etc/local/varnish, followed by a NixOS rebuild which copies them into the Nix store and activates the new configuration. To do so, run the command sudo fc-manage --build.

• service control:

  We use systemd to control processes. You can use familiar commands like sudo systemctl restart varnish to control services. However, remember that invoking sudo fc-manage --build is necessary to put configuration changes into effect. A simple restart is not sufficient. For further information, also see Local configuration.

Role configuration

Your custom configuration goes to /etc/local/varnish/default.vcl. Please note that all configuration has to be performed as a service user.

Monitoring

• We monitor that the varnishd process is running.

• Please add a custom http checks which suite your needs to to /etc/local/sensu-client, for instance:

  {
    "varnish": {
      "command": "check_http -H localhost -p 8080",
      "notification" : "varnish broken",
      "interval": 120,
      "standalone": true
    }
  }