Re: [monit-dev] [PATCH] Pass correct MONIT_DESCRIPTION env variable for external program

[Jan-Henrik Haukeland]

Hi Marco

Thank you very much for the patch. That looks like a minor bug yes. Your patch 
looks fine, though we'll discuss if there are other ways to resolve the problem 
or if we will apply the patch.

Thanks again.

Jan-Henrik


On Jul 23, 2010, at 1:46 PM, Marco Roeland wrote:

> Hello,
> 
> I use a "check host" statement in which multiple ports are monitored. The
> alerts are passed on to an external script which uses the environment
> variables that monit sets. In some cases where multiple "failed" and
> "succeeded" events are raised, the value for MONIT_DESCRIPTION is
> wrong, namely that of a different event. The existing code always seems
> to use Event_get_message() for the first entry in the eventlist, even if
> the event itself is not the first on that list.
> 
> The attached patch fixes this for me, although it is quiet invasive as
> it modifies the "spawn" prototype. Perhaps someone sees a more elegant
> solution?
> 
> The patch is against SVN revision 205 on "trunk".
> 
> Here is an example snippet for monitrc to illustrate the situation:
> 
> check host appserver with address 192.168.1.1
>       start program = "/home/marco/bin/appserver --workdir 
> /home/marco/testsuite/appserver --daemon"
>       stop program = "/home/marco/bin/appserver --workdir 
> /home/marco/testsuite/appserver --quit"
>    if failed port 9080 protocol http with timeout 5 seconds
>       then exec "/home/marco/src/test-monit/bin/my_alert 'Failed for port 
> 9080'"
>       else if succeeded then exec "/home/marco/src/test-monit/bin/my_alert 
> 'Succeeded for port 9080'"
>    if failed port 9081 protocol http with timeout 5 seconds
>       then exec "/home/marco/src/test-monit/bin/my_alert 'Failed for port 
> 9081'"
>       else if succeeded then exec "/home/marco/src/test-monit/bin/my_alert 
> 'Succeeded for port 9081'"
>    if failed port 9082 protocol http with timeout 5 seconds
>       then exec "/home/marco/src/test-monit/bin/my_alert 'Failed for port 
> 9082'"
>       else if succeeded then exec "/home/marco/src/test-monit/bin/my_alert 
> 'Succeeded for port 9082'"
> 
> If say ports 9080 and 9081 fail for some time, and then 9080 is again
> available you might get the following entries in the call of my_alert for 
> port 9081:
> 
> MONIT_DESCRIPTION=connection succeeded to INET[192.168.1.1:9080] via TCP
> MONIT_EVENT=Connection failed
> argv[1]='Failed for port 9081'
> 
> Note that this "bug" (if that's what it is) only manifests itself in the
> setting of MONIT_DESCRIPTION when an external program is called, and can
> be worked around by using multiple "check host" statements.
> -- 
> Marco Roeland