global_init fails when only specifying monitor address

[Wido den Hollander <wido@widodh.nl>]

Hi,

I tried to connect to a small Ceph setup on my desktop without cephx and 
that failed:

root@stack01:~# ceph -m wido-desktop.widodh.nl:6789 -s
global_init: unable to open config file.
root@stack01:~#

I however worked with:

root@stack01:~# ceph -m wido-desktop.widodh.nl:6789 -c /dev/null -s
2012-04-26 14:55:33.828524    pg v148: 594 pgs: 594 active+clean; 0 
bytes data, 7740 KB used, 70571 MB / 76800 MB avail
2012-04-26 14:55:33.829622   mds e1: 0/0/1 up
2012-04-26 14:55:33.836144   osd e14: 3 osds: 3 up, 3 in
2012-04-26 14:55:33.886429   log 2012-04-26 14:52:50.674430 osd.1 
[2a00:f10:11c:ab:52e5:49ff:fec2:c976]:6807/28366 12 : [INF] 1.2b scrub ok
2012-04-26 14:55:33.892423   mon e1: 1 mons at 
{desktop=[2a00:f10:11c:ab:52e5:49ff:fec2:c976]:6789/0}
root@stack01:~#

I quick look at global_init.cc showed me why this happened, it simply 
looks for a configuration file to open and when it can't it fails.

But if a monitor address is set, a config file shouldn't be mandatory.

It could be accomplished rather simple by setting the flag 
CINIT_FLAG_NO_DEFAULT_CONFIG_FILE if a mon_host has been set, but to do 
that conf->parse_argv(args); should move a few lines up.

Comments? Thoughts?

Wido