cubicweb-varnish 1.0.0

Summary

This cubes enables a purge mechanism for a cubicweb website that is sitting behind a varnish cache.

Internals

The purge mechanism consists of sending purge commands to the administration backend of varnish (by default localhost:6082). Generally it is recommended to protect this management port with a secret file which can be configured in this cube. Multiple backends can be controlled in this manner in a distributed setup.

Out of the box, this cube will not purge any URLs. The logic of which pages should be “purged” has to be implemented in content cubes.

To configure which urls to purge, you have to implement an IVarnishAdapter, for example

.. sourcecode:: python

from cubes.varnish.entities import IVarnishAdapter

class BlogEntryVarnishAdapter(IVarnishAdapter):

__select__ = is_instance(‘BlogEntry’)

def urls_to_purge(self):

return (‘/’, #frontpage

self.entity.absolute_url(), #URL of blog post ‘/BlogEntry’ # list of blog entries)

Debugging : cubicweb-varnish will not crash when it cannot connect to the administrative port, it will silently log an error in the log.

Docker & Kubernetes

When deploying on docker or kubernetes, you can configure this with :

• CW_VARNISHCLI_HOSTS=fqdn:6082,IP:PORT (csv with host:port)

• CW_VARNISH_SECRETS=/etc/varnish_shared_secret_token (filename with token in it)

Dependencies

http://www.varnish-cache.org/

or apt-get install varnish (for debian derived distributions)