pserve --daemon fails with "Bad file descriptor on the use of os.urandom()"

[zart]

From IRC discussion:

<oyse> I have a problem with running pserve --daemon. It fails with Bad file
       descriptor on the use of os.urandom()
<oyse> Is this a known problem?
<oyse> I am running Pyramid 1.5.2 on Python 3.4.0
<oyse> From what I found on internet it could be related to closing of
       filedescriptor, but I would assume that would have been taken care of a
       long time ago if that was the problem
 * Zart ran python2 and python3, and looked at /proc/<pid>/fd/
<Zart> 2.7 used socket, 3.4 opens /dev/urandom. since pserve closes every fd
       after double fork() this breaks os.urandom() on py3k..
<Zart> https://docs.python.org/3/whatsnew/3.4.html#significant-optimizations
       seems like it's 3.4 specific optimizations
<Zart> https://github.com/Pylons/pyramid/blob/master/pyramid/scripts/pserve.py#L412

So it seems that lazy-init optimizations in 3.4 might be a culprit here.

[zart]

This might have been fixed in 3.4.1 or later: http://bugs.python.org/issue21207

[digitalresistor]

Downside to trying to be too smart ...

[mcdonc]

TBH I'd rather remove the --daemon feature than add a hack for versions of Python earlier then 3.4.1. So many good process managers exist; pserve should not try to be one.

[hpfmn]

so what would you recommend to daemonize pserve?

[tseaver]

http://supervisord.org/

[mmerickel]

@hpfmn yes supervisord works well or every computer comes with its own init system for running services such as sysvinit, upstart or systemd.

[digitalresistor]

the --daemon feature has been deprecated.