please reconsider umask(0)

[Seth Arnold]

Hello; I'm conducting a very quick review of oslo.privsep as part of the Ubuntu main inclusion process.

This isn't strictly a bug but I'd like to suggest that the 'umask(0)' call here be replaced with a safer umask, e.g. 0022 or 0077:

    def run(self):
        """Run request loop. Sets up environment, then calls loop()"""
        os.chdir("/")
        os.umask(0)
        self._drop_privs()
        self._close_stdio()

        self.loop()

I know W Richard Stevens put 'umask(0)' into his daemonize() routines but I think that was a mistake. The umask mode should be a fail-safe mode rather than a fail-open mode.

Thanks