Squid server is a proxy distributed as free software. The principle of the proxy is to keep some items cached to increase the browsing speed of users. However, sometimes it can be awkward to keep some items cached, for example for a web developer wanting to view changes he has just made on a website. In the rest of this page, you will learn how to purge the elements for a selected site.

MODIFY SQUID CONFIGURATION TO ALLOW PURGE

As a first step, you need to modify the Squid configuration file (squid.conf) to allow the purge. To do this, edit the file /etc/squid/squid.conf

and add the following lines:

acl PURGE method purge
http_access allow purge localhost
http_access deny purge

You must now add a password for the cache manager (cache_mgr), always in the add a line configuration file:

cachemgr_passwd password objects

The objects option allows to limit the field of action to the manager, however it will be possible to purge the cache.

Finally, for your new configuration to be taken into account, in the console of your proxy enter the line:

squid -k reconfigure

MAKE A LIST OF OBJECTS THAT YOU WANT TO DELETE

To create a list “lst-obj”, which contains all the objects coming from the site linuxfr for example, you just have to enter the following line in the console of your proxy:

 

squidclient -p 8080 -U manager -W password mgr: objects | grep linuxen > lst-obj

 

You can view the lst-obj list with the following line:

more lst-obj
    GET http://linuxfr.org/2009/04/images/ecrire.png
    GET http://linuxfr.org/forums/images/ecrire.png
    GET http://linuxfr.org/backend/journals/rss20.rss
    GET http://linuxfr.org/~Zenitram/28107.html
    GET http://linuxfr.org/forums/10/9666.html
    GET http://linuxfr.org/forums/ 30/23427 .html
    GET http://linuxfr.org/2007/03/images/ecrire.png
    GET http://linuxfr.org/css/contrib/nightgrey.css
    GET http://linuxfr.org/css/linux_print.css
    GET http://linuxfr.org/2009/04/09/25285.html

PURGE OBJECTS IN THE LIST

 

You can now delete the objects you put in the lst-obj list, by running the following line:

cut -d "" -f2 lst-obj | xargs -n 1 squidclient -m PURGE -p 8080

The proxy then confirms the purge by displaying the list of deleted items.