[PATCH (cmogstored)] doc: document CMOGSTORED_FDS in the manpage

[Eric Wong <e@80x24.org>]

David Birdsong <david.birdsong -AT- gmail -DOT- com> wrote:
> On Wed, Nov 11, 2015 at 2:41 PM, Eric Wong <e@80x24.org> wrote:
> > It can't set environment variables?  I suppose you can use env(1) from
> > the command-line to launch cmogstored, as it always supported the
> > CMOGSTORED_FD environment.  Unlike LISTEN_FDS, CMOGSTORED_FD
> > does not validate $$ == LISTEN_PID like LISTEN_FDS does.  It
> > is comma-delimited, so it can use non-contiguous FDs:
> >
> >    env CMOGSTORED_FD=3,4 cmogstored ...
> >
> >
> it can set env, but i was thinking that the templating from the socket
> support doesn't extend into env. either way, a simple shell shm could do
> it, so yeah that's probably fine.

The env(1) command-line would be templated, actually::

	env CMOGSTORED_FD=%d,%d cmogstored ...

Just pushed the following out to cmogstored.git, too.  Thanks.

Subject: [PATCH] doc: document CMOGSTORED_FDS in the manpage

This has always been supported internally, and we can't stop
supporting it since we'll be supporting upgrades from old versions
indefinitely.  So document it, as it has some minor advantages over
the LISTEN_{FDS,PID} environment handling of systemd.
---
 cmogstored.x | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/cmogstored.x b/cmogstored.x
index a6b96e6..20eeb36 100644
--- a/cmogstored.x
+++ b/cmogstored.x
@@ -22,6 +22,12 @@ different sockets, the command line or config file must still specify
 which addresses to listen on.  This feature is available in cmogstored
 1.5.0 and later.
 
+CMOGSTORED_FD - a comma-delimited list of integer file descriptors.
+This is used internally for SIGUSR2 upgrades, but may be specified
+at startup (e.g. via env(1)) as it is not tied to LISTEN_PID
+like LISTEN_FDS is.  Unlike LISTEN_FDS, CMOGSTORED_FD does not rely
+on inherited file descriptors being contiguous.
+
 See MALLOC TUNING for environment variables which may affect memory
 usage.
 
-- 
EW