Bug 1089715

+++ This bug was initially created as a clone of Bug #888871 +++

[3] What is the nature and description of the request?

/usr/share/rhn/virtualization/poller.py (run as a cron job) provided by package="rhn-virtualization-host"
generates tracebacks (like below) without checking the status of libvirtd.

____________________________

libvir: RPC error : Failed to connect socket to '/var/run/libvirt/libvirt-sock-ro': No such file or directory
Warning: Could not retrieve virtualization information!
        libvirtd service needs to be running.
libvir: RPC error : Failed to connect socket to '/var/run/libvirt/libvirt-sock-ro': No such file or directory
Traceback (most recent call last):
  File "<stdin>", line 301, in <module>
  File "/usr/share/rhn/virtualization/domain_directory.py", line 70, in __init__
    self.conn = libvirt.openReadOnly(None)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 247, in openReadOnly
    if ret is None:raise libvirtError('virConnectOpenReadOnly() failed')
libvirt.libvirtError: Failed to connect socket to '/var/run/libvirt/libvirt-sock-ro': No such file or directory
____________________________

Which is annoying.


[4] Why does the customer need this? (List the business requirements here)

Customer does not want unwanted tracebacks to be sent as mails - even when libvirtd is running.
The following is *un-acceptable* to the customer.

In /etc/cron.d/rhn-virtualization.cron :

======
0-59/2 * * * * root python < /usr/share/rhn/virtualization/poller.py &> /dev/null
======

This was not be acceptable to them as only the poller.py traces are directed to /dev/null
There exists no easy way for their support-team to get notified if libvirtd crashes/is stopped or 
something else (since poller.py depends upon libvirtd)

but they require the libvirtd crashes *also* be reported to them via mails
This is easier for their SUPPORT team to read and get notified about.



[5] How would the customer like to achieve this? (List the functional requirements here)

- The poller.py should check the status of the libvirtd and only execute when it finds 
  that libvirtd is stopped.
- The cron-job "/etc/cron.d/rhn-virtualization.cron" should be modified to execute in such a way that
  the poller.py comes into action only when libvirtd is detected as stopped.



[8] List any affected packages or components: rhn-virtualization-host


[10] Additional Note:

The following solution was *acceptable* to the customer.

Modify /etc/cron.d/rhn-virtualization.cron as below in the next release version of "rhn-virtualization-host"
like below

=====
0-59/2 * * * * root [ -S /var/run/libvirt/libvirt-sock-ro ] && python < /usr/share/rhn/virtualization/poller.py
===== 

- Addition of "[ -S /var/run/libvirt/libvirt-sock-ro ] &&" will check libvirtd service is running or not.
- If running will execute poller.py, otherwise skip it from running. 

The advantage of this check is that, it will prevent poller.py from executing 
(if libvirtd service is stopped) and hence prevents 
the tracebacks generated due to libvirtd not running. 
At the same time will capture the error message generated by the poller.py 
script when libvirtd is running.