[Pacemaker] pcs: Return code handling not clean

[Chris Feist]

On 04/16/13 06:46, Andreas Mock wrote:
> Hi all,
>
> as I don't really know, where to address this
> issue, I do post it here. On the one handside
> as an information for guys scripting with the
> help of 'pcs' and on the other handside with
> the hope that one maintainer is listening
> and will have a look at this.
>
> Problem: When cluster is down a 'pcs resource'
> shows an error message coming from a subprocess
> call of 'crm_resource -L' but exits with an
> error code of 0. That's something which can
> be improved. Especially while the python code
> does have error handling in other paces.
>
> So I guess it is a simple oversight.
>
> Look at the following piece of code in
> pcs/resource.py:
>
> 915     if len(argv) == 0:
> 916         args = ["crm_resource","-L"]
> 917         output,retval = utils.run(args)
> 918         preg = re.compile(r'.*(stonith:.*)')
> 919         for line in output.split('\n'):
> 920             if not preg.match(line) and line != "":
> 921                 print line
> 922         return
>
> retval is totally ignored, while being handled on
> other places. That leads to the fact that the script
> returns with status 0.

This is an oversight on my part, I've updated the code to check retval and 
return an error.  Currently I'm not passing through the full error code (I'm 
only returning 0 on success and 1 on failure).  However, if you think it would 
be useful to have this information I would be happy to look at it and see what I 
can do.  I'm planning on eventually having pcs interpret the crm_resource error 
code and provide a more user friendly output instead of just a return code.

Thanks,
Chris

>
> Interestingly the error handling of the utils.run call
> used all over the module is IMHO a little bit inconsistent.
> If I remember correctly Andrew did some efforts in the
> past to have a set of return codes comming from the
> base cibXXX and crm_XXX tools. (I really don't know
> how much they are differentiated). Why not pass them
> through?
>
> Best regards
> Andreas Mock
>
>
>
>
> _______________________________________________
> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org
>