Re: use of "invoke-rc.d PACKAGEstop∣∣exitPACKAGE stop || exit PACKAGEstop∣∣exit?" in prerm scripts (original) (raw)

Michael Prokop wrote:

inside their prerm maintainer scripts. If stopping $PACKAGE through invoke-rc.d/init-script fails, removing the package fails as well.

Using:

invoke-rc.d $PACKAGE stop || true /etc/init.d/$PACKAGE stop || true

We are using chroot environments (e.g. with sid) where no daemon is running and invoke-rc.d will only do an "exit 0" in those chroots.

How do you achieve that? For example symlinking invoke-rc.d to /bin/true is a workaround, but I'm searching for a general solution to avoid that daemons are started when upgrading even though they did not run before the upgrade (or don't start any service at all, e.g. in chroots - as you mentioned).

Via /usr/sbin/policy-rc.d, e.g.:

#!/bin/sh

are we on hamilton?

WHERE=$(hostname -s|cut -b 1-8) # cut to remove {1,2} from hamilton{1,2} if [ "$WHERE" = "hamilton" ]; then # notify invoke-rc.d that nothing should be done -- we are in a chroot exit 101 else # allow it exit 0 fi

(This chroot is used on the clients as their root environment)

Using the method above, wouldn't there be any chance that a bad init script could kill daemons started outside the chroot?

The init script would be broken then. Anyway, I don't see the difference between "stop || exit $?" and "stop || true" in this case.

What I mean is that the call of

invoke-rc.d $PACKAGE stop || true

is fine, but the second call

/etc/init.d/$PACKAGE stop || true

will not using policy-rc.d and therefore might be a possible problem. Given the fact that we have a sid chroot on a high availibilty system and a sid package always might cause some trouble, I don't like the idea that a malformed script is able to stop programs outside its chroot.

Cheers, Bernd

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