How to purge Squid /varnish stale/outdated pages programmatically

>>>For SQUID, you need to enable the Purge Request for IP and Send a Request to the Squid server using the PURGE http method.

squid.conf, enable Purge request from a given devices.

acl localnetwork 10.10.8.1/255.255.255.255.0 http_access allow PURGE localnetwork

you can use squidclient utility

squidclient -m Purge http://squidserver:2128/foo.html

Here is one C# code snippet.

string url = http://squidserver:3128/fooo.html; //Squid IP: Port  WebRequest req = HttpWebRequest.Create(url); req.Method = "PURGE"; try             { HttpWebResponse resp = (HttpWebResponse)req.GetResponse(); if (resp.StatusCode == HttpStatusCode.OK)                 { Console.WriteLine("PURGE Sucessful");                 } else                 { Console.WriteLine("PURGE Failed");                 }             } catch (WebException ex)             { Console.WriteLine("PURGE Failed" + ex.Message);             }

>>> Varnish , two ways.
option 1, send the purge directive from the admin console. (when you start the varnishd, add one –T for the admin port, i,e 7777)  varnishd –a 0.0.0.0:8888 –T 0.0.0.0:7777 –f  youvcl.vcl

then telnet to the 7777 admin port, enter “purge req.url ~ foo.html” , this will put a switch mark for all url matching the expression foo.htm

also, this process can be implemented in the C# code.

string url = "fooo.html"; //URL regular expression TcpClient t = new TcpClient(); t.Connect("varnishserver", 7777); //varnish admin port NetworkStream ns = t.GetStream(); StreamReader sr = new StreamReader(ns); System.Threading.ManualResetEvent mre = new ManualResetEvent(false); new Thread(                 (object obj) =>                 { while (true)                     { if (ns.DataAvailable)                         { Console.WriteLine(sr.ReadLine());                         } if (mre.WaitOne(TimeSpan.FromSeconds(3)) == true)                         { break;                         }                     }                 }                 ).Start(); StreamWriter sw = new StreamWriter(ns); sw.Write("purge req.url ~ " + url + sw.NewLine); sw.Flush(); ns.Flush(); mre.Set();

Option 2, put a logic in the recv VCL, intercept the PURGE method and call the purge method.

sub vcl_recv {         if (req.request == "PURGE") {                 if (!client.ip ~ purge) {                         error 405 "Not allowed.";                 }                 purge("req.url == " req.url );                 error 200 "Purged.";         } }

the code is the same like the squid options.