Bug#727708: upstart and upgrading from sysvinit scripts

[Russ Allbery <rra@debian.org>]

Steve Langasek <vorlon@debian.org> writes:
> On Sat, Dec 28, 2013 at 04:45:38PM -0800, Russ Allbery wrote:

>> After some more experimentation (the documentation doesn't say clearly
>> whether pre-start can expose environment variables to exec or not), it
>> looks like a better approach is:

>>     expect stop

>>     pre-start script
>>         test -x /usr/sbin/lbcd || { stop; exit 0; }
>>         if [ -f /etc/default/lbcd ] ; then 
>>             . /etc/default/lbcd
>>         fi
>>     end script

>>     # To change the default lbcd service, specify a command to run for the
>>     # weight and interval, or do round-robin (-R), set the desired flags
>>     # in DAEMON_OPTS in /etc/default/lbcd.
>>     exec /usr/sbin/lbcd -f -l -Z $DAEMON_OPTS

>> This seems to work and is what I will be uploading.

> Hmm, It seems to not be what you uploaded in practice... which stands to
> reason, since in fact no, the pre-start script cannot export environment
> variables to the main process (for standard unixy reasons - upstart
> doesn't do anything magical here to try to tie the process environments
> together, so when the pre-start script exits, its environment goes with
> it.  This could be documented better).  I guess you figured this out
> after having written this mail?

Yes, indeed, sorry, that's correct.  This is the mail message that got
stuck behind the buggy virus definition, and I forgot to go back and
update it with the current results.  What I uploaded went back to using a
script for the whole thing:

    pre-start script
        test -x /usr/sbin/lbcd || { stop; exit 0; }
    end script
    
    # To change the default lbcd service, specify a command to run for the
    # weight and interval, or do round-robin (-R), add the flags to
    # DAEMON_OPTS in /etc/default/lbcd.  This will ensure consistent
    # behavior across all init systems.
    script
        if [ -f /etc/default/lbcd ] ; then
            . /etc/default/lbcd
        fi
        exec /usr/sbin/lbcd -f -l -Z $DAEMON_OPTS
    end script

-- 
Russ Allbery (rra@debian.org)               <http://www.eyrie.org/~eagle/>