Support for systemd

[Tollef Fog Heen]

]] Ingvar Hagelund 

Hi Ingvar, thanks for raising this discussion,

| The last chapter in the saga of sysv init replacements is systemd
| (1). Fedora 15 has shipped with systemd (2). From what I've heard,
| Debian (3) and OpenSuSE (4) is migrating. Ubuntu has not made any
| public announcements on using systemd yet, but there is experimental
| support (5) .

Debian's supporting systemd, but the decision on whether to move to it
by default or not has in no way been taken.  (I'm part of the
discussion, as I maintain systemd in Debian.)

[...]

| Win: A common systemd unit file for many linux distributions may be
| distributed and maintained upstream.

Yup, would be good.

| Win: Interesting extra features; Some socket activation mechanism that
| might make varnishd restart completely without loosing
| connections. (No, I know absolutely nothing about how this works.)

This is somewhat harder to do, but in no way impossible, I think.

| A problem is the way varnish starts up, by reading its startup
| configuration from environment variables in
| /etc/{sysconfig|defaults}/varnish. systemd does support reading files
| with environment variables, but only as a list of VAR=val statements,
| and not the cumulative way the default sysconfig|defaults file is
| built up.
| 
| Easiest fix for me, most work for developers: Skip the shell based
| startup that is used by Red Hat, SuSE and Debian derivates, and make
| varnish itself read its configuration from a file (as an alternative
| to only support command line options startup).

I think this would be ok in any case, and it's not really that much
work.

-- 
Tollef Fog Heen
Varnish Software
t: +47 21 98 92 64