varnish configtest

Question

Is there a way to check varnish configuration syntax without actually using the new version?

I'm searching for a native varnish equivalent of apache2ctl configtest

Answer 1

You can ask Varnish to compile your VLC file to a temporary file. This is part of our script that loads a new configuration into our varnish servers:

tmpfile=$(mktemp)
trap 'rm -f $tmpfile' 0
varnishd -C -f /srv/web/fe/varnish/default.vcl > $tmpfile
echo

if [ ! -s $tmpfile ]; then
    echo "ERROR: There are errors in the varnish configuration." >&2
    exit 1
fi

This works because varnishd -C will not generate any output on stdout if there are errors in the VCL.

Answer 2

What's about varnish_reload_vcl?

Some examples:

1. Without problems in your VCL file

   $ varnish_reload_vcl
   Loading vcl from /etc/varnish/default.vcl
   Current running config name is reload_2016-01-28T15:18:23
   Using new config name reload_2016-01-28T15:19:57
   VCL compiled.
   VCL 'reload_2016-01-28T15:19:57' now active
   available       0 boot
   available       0 reload_2016-01-28T14:40:04
   available       0 reload_2016-01-28T14:42:07
   available       0 reload_2016-01-28T14:42:32
   available       0 reload_2016-01-28T14:47:45
   available       0 reload_2016-01-28T14:48:45
   available       0 reload_2016-01-28T14:50:26
   available       0 reload_2016-01-28T14:55:55
   available       0 reload_2016-01-28T15:18:23
   active          0 reload_2016-01-28T15:19:57
   
   Done
   

2. With an error in your VCL file

   $ varnish_reload_vcl
   Loading vcl from /etc/varnish/default.vcl
   Current running config name is reload_2016-01-28T15:19:57
   Using new config name reload_2016-01-28T15:21:51
   Message from VCC-compiler:
   Symbol not found: 'b1' (expected type BACKEND):
   ('input' Line 77 Pos 32)
           set req.backend_hint = b1;
   -------------------------------##-
   
   Running VCC-compiler failed, exited with 2
   VCL compilation failed
   Command failed with error code 106
   varnishadm -S /etc/varnish/secret -T 127.0.0.1:6082 vcl.load failed