[Pkg-sysvinit-devel] Bug#545448: Bug#545448: invoke-rc.d should indicate whats wrong when not starting services

[Henrique de Moraes Holschuh]

On Mon, 07 Sep 2009, Patrick Schoenfeld wrote:
> On Mon, Sep 07, 2009 at 11:26:38AM +0200, Petter Reinholdtsen wrote:
> > [Patrick Schoenfeld]
> > > recently I stumbled across some behaviour in invoke-rc.d which I
> > > consider somehow broken. When trying to start a service with
> > > invoke-rc.d it sometimes refuses to start the service, without a
> > > notice whats wrong. Of course not starting services under some
> > > circumstances is OK, but not telling the user whats wrong isn't.
> > 
> > When does this happen?  How can we reproduce it?  Currently your
> > request is to vague for me to know what do adress. :)
> 
> Good question. If the program had proper diagnostic messages
> in the first place, it would be easier to answer. What I had,
> where it happened, is an LSB header like this in the init script:
> 
> # Default-Start:  3 5
> # Default-Stop:   0 1 2 6
> 
> System was in runlevel 2, so this script probably did not
> start because of the wrong runlevel. Script was installed
> with update-rc.d defaults.

I.e. invoke-rc.d was doing exactly what it has to do.  The script is not to
accept "start" or "restart" actions on runlevel 2.  It will allow "stop"
actions, though.  Invoke-rc.d will not let you start that script unless you
are at runlevel 3 or runlevel 5, and it will let you stop it on any
runlevel.  It will let you do anything on runlevel 4 (since behaviour is
undefined, and doing otherwise would expose bugs on many packages that have
runlevel S scripts).

> The output of invoke-rc.d was simply nothing. RC = 0.

Which is also correct, invoke-rc.d is to be used in maintainer scripts, its
result codes in default mode of operation are optimized for that usage.

> Starting it with --disclose-deny yields into rc 101. Thats
> something to start with, but actually not very much.

Why are you using invoke-rc.d manually to begin with?  What is the use case
that is causing problems?

> Basically the behaviour is similar as described in the
> already existing bug reports, with the description that
> invoke-rc.d simply does not start something, like
> #452119 or #385593. BTW. the first has the sh -x output
> attached which you asked for.

invoke-rc.d exists ONLY to make sure package maintainer scripts will NOT
start something out-of-runlevel (and to let someone add more policies using
a separate script, policy-rc.d, very useful for build daemons and build
chroot jails).  The local admin is not supposed to need this unless he has
some very weird scripts that should obey the rules just like package
maintainers do.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh