webcarrot / libvmod-imgdata

Varnish Imgdata Module

vmod_imgdata

Varnish Imgdata Module

Author

Wojciech Wierchola <[e-mail]>

Date

2014-07-26

Version

0.1

Manual section

3

SYNOPSIS

Basically based on Aivars Kalvans libvmod-rewrite.

Using CURL to download images and GNU coreutils base64 implementation.

DESCRIPTION

Varnish vmod that replace images urls with

"data:image/{EXT};base64,{IMAGE_DATA}".

Imgdata is performed only once and the rewritten document is stored in cache.

FUNCTIONS

imgdata_re

Prototype

imgdata_re(STRING POSTFIX_REGEX)

Return value

VOID

Description

Replace all parts of document matching

"https?://[^"' ]+\.(jpgpng|gif){POSTFIX_REGEX}"

with

"data:image/{EXT};base64,{IMAGE_DATA}"

INSTALLATION

Usage:

./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

In your VCL you could then use this vmod along the following lines:

import imgdata;

sub vcl_deliver {  
    if (
        resp.http.Content-Type ~ "text/html" ||
        resp.http.Content-Type ~ "text/css"  ||
        resp.http.Content-Type ~ "application/json"
    ) {
        imgdata.imgdata_re("\?inline=true");
    }
}

TODO

• Database/cache for base64 form of images
• Output compression
• Output content buffer updates optimization

COPYRIGHT

Wojciech Wierchola 2014

See LICENCE (GPLv3) for details.