[ovs-dev] [PATCH 4 of 5] Clear stale configuration keys on boot

[Ian Campbell]

On Wed, 2009-09-30 at 21:20 +0100, Ben Pfaff wrote:
> Ian Campbell <ian.campbell at citrix.com> writes:
> 
> > diff -r 655d69fcd68a -r aa941ec68c03 xenserver/etc_init.d_vswitch
> > --- a/xenserver/etc_init.d_vswitch	Wed Sep 30 11:17:45 2009 +0100
> > +++ b/xenserver/etc_init.d_vswitch	Wed Sep 30 11:38:22 2009 +0100
> > @@ -264,6 +264,12 @@
> >      if [ ! -e "$VSWITCHD_CONF" ]; then
> >          warning "$VSWITCHD_CONF does not exist"
> >          action "Creating empty $VSWITCHD_CONF" touch "$VSWITCHD_CONF"
> > +    else
> > +	/usr/bin/ovs-cfg-mod '-vANY:console:emer' -F "$VSWITCHD_CONF" \
> > +	    '--del-match=bridge.*' \
> > +	    '--del-match=port.*' \
> > +	    '--del-match=bonding.*' \
> > +	    '--del-match=iface.*'
> >      fi
> 
> It makes a lot of sense to do this (frankly we ought to have been
> doing this all along) but doing it here will break "service
> vswitch restart", which normally works OK, at least for me.

I hadn't considered that.

> We
> need some way to only delete all that on first boot, but not
> later.  I wonder if there's a good way to tell.  We could just
> avoid it when "restart" is used, but then anyone who does
> "service vswitch stop; service vswitch stop" gets screwed, which
> is not good either.
> 
> Is there a good way to tell that this is the first time we're
> being run?  Maybe we can create a file in /var/run, since that
> gets cleaned at boot time.

Yes, I think that would work and I can't think of much else. I think it
would be possible to tell if the script is being run by init vs manually
(by hand or via the service command) but I suspect that would break
changing runlevels.

Is it worth considering splitting the persistent and ephemeral
configuration into separate files (or just providing an "include" type
directive)? Then it would be possible to put the ephemeral stuff itself
under /var/run.

Will the config database changes effect this in any way?

Ian.