How do I make Varnish purge all variants of a URL? - varnish

Question

Varnish 2.1: I'm trying to use http PURGE to get Varnish to renew one cached URL.
While testing, I would get results that seemed strange until I read this bit in the documentation: "If there are several variants of the same URL in the cache however, only the matching variant will be purged. To purge a gzip variant of the same page the request would have to look like this:"
So now if I do these two commands:
curl -I http://example.com/my-url
curl -X PURGE http://example.com/my-url
I get back a 200 Purged response.
And if I do these two:
curl -I http://example.com/my-url -H "Accept-Encoding: gzip"
curl -X PURGE http://example.com/my-url -H "Accept-Encoding: gzip"
I also get a 200 Purged.
Now if I try:
curl -I http://example.com/my-url -H "Accept-Encoding: deflate"
I get back headers that indicate that the Content-Encoding: is "text/html;charset=utf-8", and it has age in the cache. That seems to indicate that "deflate" isn't being supported by my app, which is probably correct.
The page also has an Age: header indicating that it's being cached.
Now how do I purge that? (Am I asking a moot question?)
All of these attempts return "404 Not in cache":
curl -X PURGE http://example.com/my-url -H "Accept-Encoding: deflate"
curl -X PURGE http://example.com/my-url -H "Accept-Encoding: text/html;charset=utf-8"
curl -X PURGE http://example.com/my-url -H "Accept-Encoding: text/html"
Is there a magic way to purge all of the variants of a URL?

Answer 1

Aha, by applying some google-fu, I stumbled on a forum post, that suggests the following:
purge("req.url ~ ^" req.url "$");
i.e. using a regexp behind purge, to handle all Accept-Encoding headers.
More info here: http://www.gossamer-threads.com/lists/varnish/misc/15124
.. which means you need to modify your VCL though.

Answer 2

I think this is what u need:
acl purge {
"localhost";
"192.168.55.0"/24;
}
sub vcl_recv {
# allow PURGE from localhost and 192.168.55...
if (req.request == "PURGE") {
if (!client.ip ~ purge) {
error 405 "Not allowed.";
}
return (lookup);
}
}
sub vcl_hit {
if (req.request == "PURGE") {
purge;
error 200 "Purged.";
}
}
sub vcl_miss {
if (req.request == "PURGE") {
purge;
error 200 "Purged.";
}
}