[systemd-devel] systemctl is-enabled...

[Bill Nottingham]

The implementation of the is-enabled command makes its not necessarily
useful as I might expect it to be. From looking at it, it merely checks
whether the '[Install]' section has been executed. That means that it's
not going to be correct for any service that has been enabled via other
means, or doesn't have an '[Install]' section.

For example:

$ systemctl status dbus.service
dbus.service - D-Bus System Message Bus
	  Loaded: loaded (/lib/systemd/system/dbus.service)
	  Active: active (running) since Wed, 02 Mar 2011 16:52:58 -0500; 1
day and 21h ago
	Main PID: 721 (dbus-daemon)
	  CGroup: name=systemd:/system/dbus.service
		  ├  721 /bin/dbus-daemon --system --address=systemd:
--nofork --systemd-activ...
...
$ ls -l /lib/systemd/system/multi-user.target.wants/dbus.service 
lrwxrwxrwx. 1 root root 15 Feb 14 12:33
/lib/systemd/system/multi-user.target.wants/dbus.service -> ../dbus.service
$ systemctl is-enabled dbus.service ; echo $?
1

Or, to take a different example. Most services set
'WantedBy=multi-user.target' in their '[Install]' section. But the
administrator/system designer decides to make a custom target, with custom
services enabled via symlinks in /etc. By my reading, 'systemctl is-enabled'
will never return "correct" values in this case.

Am I missing something? Is there a different command that should be used?
It seems a more full implementation would parse the dependency graph for
either the current or given target, and check that the service is wanted
by some part of that.

Bill