[Pacemaker] Stonith setup hostname params

[Dejan Muhamedagic]

On Fri, Apr 01, 2011 at 09:41:26AM +0200, Andrew Beekhof wrote:
> On Tue, Mar 29, 2011 at 3:28 PM, Dejan Muhamedagic <dejanmm at fastmail.fm> wrote:
> > On Mon, Mar 28, 2011 at 09:08:32PM +0400, Pavel Levshin wrote:
> >> 28.03.2011 18:35, Dejan Muhamedagic:
> >>>> Currently, crm shell cannot handle quoted parameters with spaces from the command line. Try to enter it interactively:
> >>> The crm shell gets what bash (or dash) passes. The quotes are
> >>> gobbled by bash in that process. Basically, what you type is not
> >>> what crm sees.
> >>>
> >>
> >> I understand the mechanics. It is machine-centric and confusing to some
> >> users.
> >>
> >> It is not absolutely impossible to accept quoted parameters from command
> >> line. Quotes are stripped, but these parameters are preserved in single
> >> arguments.
> >>
> >>> Right. I really don't understand why's everybody trying to
> >>> configure the cluster directly from bash instead of doing it in
> >>> crm configure.
> >>>
> >>
> >> CRM shell offers this opportunity, that's why many users try to use it.
> >
> > The fact that the shell has this feature doesn't mean that it
> > should be misused. It was meant mainly for one-off management
> > commands (such as "resource stop" or "node standby") and only
> > very seldom for one-off configuration commands. There's a
> > plethora of things which can go wrong when used for
> > configuration directly from the command line. It also makes the
> > cluster work harder because every invocation has an implicit
> > commit and the changes immediately take effect.
> 
> There are, as CTS shows, ways around that.

You mean using CIB_file? Yes, that's one possibility, though I'm
not sure how many people know about it. Another would be to do
the changes in a shadow CIB.

> > Because of that
> > the user also must pay attention to the order of configuration
> > elements which otherwise isn't necessary.
> 
> Can you define constraints for resource's you've not defined yet?
> What about clone or group resource's that are also not yet defined?
> 
> (If yes to either, that sounds more like a bug than a feature)

What I meant is this: If you stuff all the configuration into a
file and do "configure load" or just feed it to "crm configure",
the order of elements in the file does not matter as long as all
referenced elements are presents at the commit time.

> > It's a bit like taking
> > apples one by one from your garden into the house, instead of
> > bringing over a box of apples. Just worse than that. I could go
> > on, btw.
> 
> I'm sorry, but this is all a pretty weak argument.
> Not that I consider proper quote escaping the crm shell's problem, but
> the ability to script the creation of a config is quite important.

The proper way to script a configuration would be by way of
here-document or similar.

> What about adding some additional sanity checking for the params section?
> It should be pretty easy to spot (and warn about) entries not of the
> form "name=value" which would be indicative of a quoting error.

Unfortunately, CIB allows a parameter to be defined but not have
a value, that's why a token by itself within parameters is
considered to be this case.

Thanks,

Dejan

> You could then either leave it up to the admin to supply the correct
> form or try to reconstruct the intended meaning.
> 
> 
> >
> >> But, unfortunately, the feature is not uniform with interactive shell.
> >
> > How's that now? I know that many people don't understand how
> > shell (as in bash) work, but don't understand how crm shell can
> > work around that. If you have an idea, please speak up.
> >
> > Thanks,
> >
> > Dejan
> >
> >
> >> --
> >> Pavel Levshin
> >>
> >>
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> >> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
> >>
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> >
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> >
> > Project Home: http://www.clusterlabs.org
> > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> > Bugs: http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker
> >