Setup Varnish and Apache2 on Ubuntu 17.04 / 17.10

Varnish is an opensource HTTP accelerator. It is usually configured to sit in front of webservers to quickly serve HTTP/HTTPS requests. Varnish can also be used as load balancer to distribute loads across multiple webservers.

This brief tutorial is going to show students and new users how to install and configure Varnish with Apache2 on Ubuntu 17.04 / 17.10. In this post, we’ll setup Varnish to be the doorway or front-end to Apache2 to quickly serve HTTP requests.

When you configure Varnish to be the font-end to Apache2 or other webservers, it can greatly enhance the server performance. This is because Varnish stores web caches in system’s memory ensuring faster retrieval in subsequent requests for the same resource.

To get this working, follow the steps below:

Step 1: Install Apache2

First run the commands below to install Apache2 webserver.

sudo apt-get update
sudo apt-get install apache2

After installing Apache2, the commands below can be used to stop, start and enable Apache2 to always startup everytime the server boots up.

sudo systemctl stop apache2.service
sudo systemctl start apache2.service
sudo systemctl enable apache2.service

By default apache2 HTTP service automatically is bond to port 80 and 443 for HTTPS. This

Step 2: Install Varnish

Now that Apache2 is installed, run the commands below to install Varnish

sudo apt-get install varnish

After installing Varnish, the commands below can be used to start, stop and enable Varnish to always start up when the server boots

sudo systemctl stop varnish.service
sudo systemctl start varnish.service
sudo systemctl enable varnish.service

Step 3: Switch Apache2 default post to 8080

Since we want Varnish to listen for all traffic coming to port 80 which is Apache2 default port, let’s configure Apache2 to use another port number. You can open Apache2 default port configuration file at /etc/apache2/ports.conf and change the Listen value to 8080.

To quickly change the port run the commands below to open Apache2 default port configuration file.

sudo nano /etc/apache2/ports.conf

Then make sure the file has these lines. Save when done.

# If you just change the port or add more ports here, you will likely also
# have to change the VirtualHost statement in
# /etc/apache2/sites-enabled/000-default.conf

NameVirtualHost 127.0.0.1:8080
Listen 127.0.0.1:8080

Next, open Apache2 default virtualhost config file.

sudo nano /etc/apache2/sites-available/000-default.conf

Then make the highlighted change below.

## Alternative 2, Configuration with VCL
#
# Listen on port 6081, administration on localhost:6082, and forward to
# one content server selected by the vcl file, based on the request.
#
DAEMON_OPTS="-a :80 
-T localhost:6082 
-f /etc/varnish/default.vcl 
-S /etc/varnish/secret 
-s malloc,256m"

# Default backend definition. Set this to point to your content server.
backend default {
.host = "127.0.0.1";
.port = "8080";
}

sudo systemctl restart apache2.service
sudo systemctl restart varnish.service

HTTP/1.1 200 OK
Date: Sun, 23 Jul 2017 17:45:49 GMT
Server: Apache/2.4.25 (Ubuntu)
Last-Modified: Sun, 23 Jul 2017 17:01:05 GMT
Vary: Accept-Encoding
Content-Type: text/html
X-Varnish: 10 3
Age: 9
Via: 1.1 varnish (Varnish/5.0)
ETag: W/"2aa6-554ff0b3c88c9-gzip"
Accept-Ranges: bytes
Connection: keep-alive