NAME

vmod_purge - Varnish Purge Module

SYNOPSIS

import purge [as name] [from "path"]
INT hard()
INT soft(DURATION ttl, DURATION grace, DURATION keep)

DESCRIPTION

vmod_purge contains functions that offer a finer-grained control than return(purge) from vcl_recv{}. The functions can only be called from vcl_hit{} or vcl_miss{} and they should in general be used in both to ensure that all variants of a same object are taken care of.

EXAMPLE

sub vcl_recv {
    if (req.method == "PURGE") {
        if (client.ip !~ purge_acl) {
            return (synth(405));
        }
        return (hash);
    }
}
sub my_purge {
    set req.http.purged = purge.hard();
    if (req.http.purged == "0") {
        return (synth(404));
    }
    else {
        return (synth(200));
    }
}
sub vcl_hit {
    if (req.method == "PURGE") {
        call my_purge;
    }
}
sub vcl_miss {
    if (req.method == "PURGE") {
        call my_purge;
    }
}
sub vcl_synth {
    if (req.method == "PURGE") {
        if (req.http.purged) {
            set resp.http.purged = req.http.purged;
        }
        return (deliver);
    }
}

INT hard()

This is equivalent to return(purge) but explicitly called from vcl_hit{} and vcl_miss{}. It returns the number of purged objects.

Example:

set req.http.purged = purge.hard();

INT soft(DURATION ttl, DURATION grace, DURATION keep)

INT soft(DURATION ttl=0, DURATION grace=-1, DURATION keep=-1)

Sets the ttl, grace and keep.

By default, ttl is set to 0 with grace and keep periods left untouched. Setting a negative value for grace or keep periods leaves them untouched. Setting all three parameters to 0 is equivalent to a hard purge. It can only be called from vcl_hit{} or vcl_miss{}. It returns the number of soft-purged objects.

COPYRIGHT

Copyright (c) 2017 Varnish Software AS
All rights reserved.
Author: Dridi Boukelmoune <dridi.boukelmoune@gmail.com>
SPDX-License-Identifier: BSD-2-Clause
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.