Varnish is an amazing frontend cache that is useful for serving static pages and reducing load on your server. In periods of high server activity and traffic, Varnish can be a life saver. Also, Varnish is extremely fast and effective at reducing your page load times, which helps with your SERPs and improves user experience.
1. Add the Varnish Repository
Varnish can be installed by adding the Varnish repository to your sources and using apt-get to install it.
To add the repository, run the following command:
$ sudo curl http://repo.varnish-cache.org/debian/GPG-key.txt | sudo apt-key add -
2. Edit List of apt Sources
Open the /etc/apt/sources.list in your favorite text editor so we can add the Varnish repository.
$ sudo vim /etc/apt/sources.list
Next, add the Varnish repository at the end of the file.
$ deb http://repo.varnish-cache.org/ubuntu/ lucid varnish-3.0
Save your work and exit out to the command line.
3. Install Varnish
Use the usual apt-get to install Varnish.
$ sudo apt-get update $ sudo apt-get install varnish
4. Configure Varnish DAEMON_OPTS
Now it is time to configure Varnish. This process will vary depending upon your CMS and/or framework and how your site is set up, but we will get you started with a basic configuration.
Open the /etc/default/varnish file:
$ sudo vim /etc/default/varnish
Look for “alternative 2” and uncomment the following code. Change the ports as necessary.
DAEMON_OPTS="-a :80 \ -T localhost:6082 \ -f /etc/varnish/default.vcl \ -S /etc/varnish/secret \ -s malloc,256m"
Basically, we are setting Varnish to use Port 80, using /etc/varnish/default.vcl as our configuration file, and allocating 256MB of memory.
5. Varnish VCL Configuration
The VCL file in Varnish is extremely important and allows for very specific configurations indicating which pages to cache, how to treat cookies, what to do about different user-agents, and so on.
The basics will be covered here, but you will need to look closely at the VCL file in the future to get optimal performance. Don’t worry because it’s straightforward and you can do it!
Open the VCL file:
$ sudo vim /etc/varnish/default.vcl
Now we have to tell Varnish where to grab content for your site. Here we are using the same server and we will set up Apache on port 8888.
backend default { .host = “127.0.0.1”; .post = “8888”; } Save and exit the file.
6. Change the Apache Ports
By default, Apache is configured to run on Port 80. We will change the port to be 8888.
Open the Apache ports file:
$ sudo vim /etc/apache2/ports.conf
Now look for the NameVirtualHost and Listen lines and change them to Port 8888.
NameVirtualHost 127.0.0.1:8888 Listen 127.0.0.1:8888
7. In the Virtual Host, Change the Port to 8888
In the settings for your virtual host, you will need to tell Apache to look on Port 8888.
$ sudo vim /etc/apache2/sites-available/default
Now change the port:
Save the file.
8. Restart Apache and Varnish
$ sudo service apache2 restart $ sudo service varnish restart
9. Watch in Amazement at the Details of your Varnish Server Running
You can check in on Varnish with its built-in stats readout.
$ varnishstat
You are done! That was easy wasn’t it? Now you are well on your way to having a fast and efficient server configuration.
