vmod_test304

Varnish test304 Module

Author

Dag Haavi Finstad

Date

2013-12-02

Version

1.0

Manual section

3

SYNOPSIS

import test304;

DESCRIPTION

Lets you detect if the current response will end up as a 304 Not Modified. Must only be used in vcl_deliver.

The 304 logic in Varnish depends on whether or not any of the relevant headers were altered in vcl_deliver, so in general we can't know until after vcl_deliver if this response will end up as a 304.

To rely on the result from the test304() function, you must not alter either of the following after the call:

req.http.if-modified-since
req.http.if-none-match

Varnish uses the headers of the fetched object (not the copy in resp.http.*) when deciding if it will do a 304, so stripping off resp.http.etag or resp.http.last-modified in vcl_deliver will prevent the client from seeing these, but will not prevent Varnish from serving a 304.

FUNCTIONS

test304

Prototype

test304()

Return value

BOOL

Description

Returns true if this response will end up as a 304. Do not invoke this from outside of vcl_deliver.

Example

:

sub vcl_deliver {

if (test304.test304()) {

set resp.http.foo = "this is a 304";

}

}

INSTALLATION

The source tree is based on autotools to configure the building, and does also have the necessary bits in place to do functional unit tests using the varnishtest tool.

Usage:

autoreconf -vif
./configure VARNISHSRC=DIR [VMODDIR=DIR]

VARNISHSRC is the directory of the Varnish source tree for which to compile your vmod. Both the VARNISHSRC and VARNISHSRC/include will be added to the include search paths for your module.

Optionally you can also set the vmod install directory by adding VMODDIR=DIR (defaults to the pkg-config discovered directory from your Varnish installation).

Make targets:

• make - builds the vmod
• make install - installs your vmod in VMODDIR
• make check - runs the unit tests in src/tests/*.vtc

COPYRIGHT

This document is licensed under the same license as the libvmod-example project. See LICENSE for details.

• Copyright (c) 2011 Varnish Software