How to install Varnish on ubuntu

Step 1. Install varnish
sudo apt-get install varnish

Step 2. After successful installation of varnish edit /etc/varnish/default.vcl file

backend default {
.host = "127.0.0.1";
.port = "8080";
}

Step 3.Now edit the varnish configuration file /etc/default/varnish file

# Should we start varnishd at boot? Set to "yes" to enable.
START=yes

## 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. Use a 1GB
# fixed-size cache file.
#
DAEMON_OPTS="-a :80 \
-T localhost:6082 \
-f /etc/varnish/default.vcl \
-S /etc/varnish/secret \
-s file,/var/lib/varnish/$INSTANCE/varnish_storage.bin,128M"

Step 4. Configure your Apache according to varnish

a. edit /etc/apache/ports.conf
NameVirtualHost *:8080
Listen 8080

b. edit /etc/apache2/sites-available/default
NameVirtualHost *:8080
Listen 8080
-if you don't have above setting your file, leave as it is only modify the following line in this file

c. edit vhost file(Optional)
ServerName umarani.com

Step 5. Restart Apache and varnish.

a. Restart apache.
sudo /etc/init.d/apache2 restart OR
sudo service apache2 restart

b. Start varnish.
sudo /etc/init.d/varnish start OR
sudo service varnish start

You can check varnish log by "varnishlog" command
Also make sure your ports are listening properly by this command
netstat -anp --tcp --udp | grep LISTEN