[node-devel] Maybe the reason for install failed sometimes

[Bohai (ricky)]

Hi, 

I failed to install the ovirt-node. About detail info, please see the summary of ovirt.log 
at the end of the mail.

I read the code, and found the call for subprocess_closefds like below:
1426 def findfs(label):
1427     system("partprobe /dev/mapper/*")
1428     system("udevadm settle")
1429     blkid_cmd = "/sbin/blkid -c /dev/null -l -o device -t LABEL=\"" + label + "\""
1430     blkid = subprocess_closefds(blkid_cmd, shell=True, stdout=PIPE, stderr=STDOUT)
1431     blkid_output = blkid.stdout.read().strip()
1432     return blkid_output

I think when we read the stdout the command has not finished, so the real blkid can't be read.

After call of function subprocess_closefds, whether or not we need to wait for process to terminate?
For example, to call the "Popen.communicate" to wait the comand finished.

There are lots of call for subprocess_closefds like this in ovirt-node codes ,
I guess maybe they are the reason why install failed sometimes.

How do you think about this?


--------------------------/tmp/ovirt.log-----------------------------------
301 2013-08-23 01:16:17,938 - DEBUG - install - Trial 1 to find candidate (None)
302 2013-08-23 01:16:19,290 - DEBUG - ovirtfunctions - partprobe
303 2013-08-23 01:16:19,290 - DEBUG - ovirtfunctions -
304 2013-08-23 01:16:19,469 - DEBUG - ovirtfunctions - partprobe /dev/mapper/*
305 2013-08-23 01:16:19,469 - DEBUG - ovirtfunctions -
306 2013-08-23 01:16:19,670 - DEBUG - ovirtfunctions - udevadm settle
307 2013-08-23 01:16:19,670 - DEBUG - ovirtfunctions -
308 2013-08-23 01:16:19,681 - DEBUG - install - Trial 2 to find candidate (RootBackup)
309 2013-08-23 01:16:19,681 - DEBUG - install - Found candidate: RootBackup
310 2013-08-23 01:16:19,719 - DEBUG - ovirtfunctions - partprobe /dev/mapper/*
311 2013-08-23 01:16:19,719 - DEBUG - ovirtfunctions -
312 2013-08-23 01:16:19,845 - DEBUG - ovirtfunctions - udevadm settle
313 2013-08-23 01:16:19,845 - DEBUG - ovirtfunctions -
314 2013-08-23 01:16:20,030 - INFO - install -
315 2013-08-23 01:16:20,030 - INFO - install -
316 2013-08-23 01:16:20,037 - DEBUG - install - Traceback (most recent call last):
317   File "/usr/lib/python2.7/site-packages/ovirtnode/install.py", line 424, in ovirt_boot_setup
318     self.partN = int(self.disk[-1:])
319 ValueError: invalid literal for int() with base 10: ''
------------------------------------------------------------------------------------

Best regards to you.
Ricky