Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.
This add-on integrates Varnish into your DDEV project.
Installation
ddev add-on get ddev/ddev-varnish
ddev restart
Note
Run ddev add-on get ddev/ddev-varnish after changes to name, additional_hostnames, additional_fqdns, or project_tld in .ddev/config.yaml so that .ddev/docker-compose.varnish_extras.yaml is regenerated.
After installation, make sure to commit the .ddev directory to version control.
Usage
The Varnish service inserts itself between ddev-router and the web container, so that calls to the web container are routed through Varnish first. The docker-compose.varnish.yaml installs Varnish and uses the default domain as its own host name.
A docker-compose.varnish_extras.yaml file is generated on install which replaces the VIRTUAL_HOST variable of the web container with a sub-domain of the website URL. For example, mysite.ddev.site, would be accessible via Varnish on mysite.ddev.site and directly on novarnish.mysite.ddev.site.
If you use a project_tld other than ddev.site or additional_fqdns DDEV will help add hosts entries for the hostnames automagically; however, you’ll need to add entries for the novarnish.* sub-domains yourself, e.g. ddev hostname novarnish.testaddfqdn.random.tld 127.0.0.1.
Helper Commands
This add-on also providers several helper commands. These helpers allow developers to run Varnish commands from the host, however, the commands are actually run inside the Varnish container.
Command
Description
ddev varnishd
Varnish-cli
ddev varnishadm
Control a running Varnish instance
ddev varnishhist
Display Varnish request histogram
ddev varnishlog
Display Varnish logs
ddev varnishncsa
Display Varnish logs in Apache / NCSA combined log format
You may want to edit the .ddev/varnish/default.vcl to meet your needs. Remember to remove #ddev-generated from the file if you want your changes to the file preserved.
To change the Docker image:
ddev dotenv set .ddev/.env.varnish --varnish-docker-image=varnish:6.0
ddev add-on get ddev/ddev-varnish
ddev restart
Make sure to commit the .ddev/.env.varnish file to version control.
