4.2. SELinux

SELinux policies are typically provided by the upstream distribution (Fedora, Ubuntu, etc.). As new features are added to cobbler (and we do add new features frequently), those policies may become out-of-date leading to AVC denials and other problems. If you wish to run SELinux on your cobbler system, we expect you to know how to write policy and resolve AVCs.

Below are some of the more common issues you may run into with this release.

4.2.1. ProtocolError: <ProtocolError for x.x.x.x:80/cobbler_api: 503 Service Temporarily Unavailable>

If you see this when you run cobbler check or any other cobbler command, it means SELinux is blocking httpd from talking with cobblerd. The command to fix this is:

$ sudo setsebool -P httpd_can_network_connect true

4.2.2. Fedora 16 / RHEL6 / CentOS6 - Python MemoryError

When starting cobblerd for the first time (or after upgrading to 2.2.x), you may see a stack trace like the following:

Starting cobbler daemon: Traceback (most recent call last):
File "/usr/bin/cobblerd", line 76, in main
api = cobbler_api.BootAPI(is_cobblerd=True)
File "/usr/lib/python2.6/site-packages/cobbler/api.py", line 127, in init
File "/usr/lib/python2.6/site-packages/cobbler/module_loader.py", line 62, in load_modules
blip = import("modules.%s" % ( modname), globals(), locals(), [modname])
File "/usr/lib/python2.6/site-packages/cobbler/modules/authn_pam.py", line 53, in
from ctypes import CDLL, POINTER, Structure, CFUNCTYPE, cast, pointer, sizeof
File "/usr/lib64/python2.6/ctypes/init.py", line 546, in
CFUNCTYPE(c_int)(lambda: None)

This error is caused by SELinux blocking python ctypes. To resolve this, you can use audit2allow to enable the execution of temp files or you can remove the authn_pam.py module from the site-packages/cobbler/modules directory (as long as you’re not using PAM authentication for the Web UI).