varnishctl?

[Tollef Fog Heen]

Hi all,

This got triggered by bug #1415 which asks for init scripts to be able
to verify you're not just breaking your cache on a restart.  I can see
the need for such a tool, but I think it should have a bit wider scope.

Problems:

- you don't want to restart Varnish when the configuration is
  obviously broken.

- it should be possible to reload configurations without having to
  fiddle with vcl.load, vcl.use.  Coming up with new names is
  surprisingly annoying.

- Duplication of logic between RH and Debian init scripts. Varnish
  should probably be able to read a parameter file in some reasonable
  format, which will also make the transition to non-sysvinit inits
  easier.

Suggestion 1:

Write something like to apachectl.  It knows how to run a config test,
start and stop the management process.  It makes it easy to run
multiple instances (something that's more important to apache than
us).  It's a bit like a distro-independent init script, but has custom
functions (configtest for instance)

Suggestion 2:

Extend varnishadm to not only be able to talk to varnishd, but also
start and stop the management process, do a config test and so on.
Probably also extend varnishd to be able to reload the VCL somehow and
make it able to read parameters from a file.

I'm willing to work on 1.  I think it'd be fairly easy to do and keeps
the existing tools doing one thing well.

Input, opinions, etc?

-- 
Tollef Fog Heen
Technical lead | Varnish Software AS
📞: +47 21 98 92 64
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