munin-node ignores permissions

[Alex]

Hi,

I have a fedora22 system with munin-2.0.25 and have a few modules that
I just can't get to work. They all respond with some form of
"permission denied". I've disabled SELinux (security=0), and I've
checked all permissions as the user running the script.

2015/12/29-21:34:48 [3814] Error output from bind9_rndc:
2015/12/29-21:34:48 [3814]      rndc: error: open: /etc/rndc.key:
permission denied
2015/12/29-21:34:48 [3814]      rndc: could not load rndc configuration
2015/12/29-21:34:48 [3814]      /etc/munin/plugins/bind9_rndc:
/var/named/chroot/var/named/data/named.stats: Permission denied

If I change /etc/rndc.key to 644, it runs fine.

The contents of /etc/munin/plugin-conf.d/munin-node:

[bind9_rndc]
  user named
  group named
  env.querystats /var/named/chroot/var/named/data/named.stats
  env.rndc /usr/sbin/rndc
  env.graph_args --upper-limit 100 -l 0
  env.graph_scale no
  env.graph_vlabel %

I added a system() to bind9_rndc:

system("id > /tmp/123.out");

It creates the file owned by named with group nobody, despite "group
named" above. The contents of the file are:

uid=25(named) gid=99(nobody) groups=99(nobody),25(named)

Why is it ignoring the "group named" above? I've even tried creating
the config file as /etc/munin/plugin-conf.d/bind9_rndc and it still
seems to ignore it. Is that the proper place and format for it?

I have another virtually identically fc22 munin-2.0.25 system with the
same config files and it's not having a problem.

Any ideas greatly appreciated.