Better handling of systemd parametrised and other special units not listed by list-unit-files.

[mtorromeo]

This allows to query status, start, stop, restart and list units that are not actually provided by unit files. Such units cannot be enabled/disabled and that's why those actions still prefer the "list-unit-files" output over "list-units".

Units that couldn't be handled otherwise include for example mount units and sysvinit compatibility units such as those present on debian systems.

The output of a "service.running ssh" state on a debian wheezy target is:

      ID: ssh
Function: service.running
  Result: False
 Comment: The named service ssh is not available
 Changes:

after this patch:

      ID: ssh
Function: service.running
  Result: True
 Comment: The service ssh is already running
 Changes:

[ghost]

Test Failed.

If the failures are unrelated to your code, don't stress, a core developer will know these apart.
In the future, if possible, please branch off a passing commit to avoid false positives.
Refer to this link for build results: http://jenkins.saltstack.com/job/salt-pr-build/3248/

[cachedout]

This may have some bearing on #8444 too. Nice work.

[mtorromeo]

Yes, this will partially fix #8444, meaning that a service like openvpn@example can be started by salt but still cannot be enabled.

Enabling such services will require special handling of service names containg @ but I think I may try and implement it in a separate pull request, while this one can be merged on its own.

[cachedout]

@mtorromeo Sounds great. Thanks again for your work here. Looking forward to your additional PRs to improve systemd support!

[mtorromeo]

I decided to go ahead and implement here the missing pieces to handle parametrised units in the systemd state.

With this a state such as the following will work as expected:

dhcpcd@eth0:
service.running:
  enable: True
  reload: True

[ghost]

Test Failed.

If the failures are unrelated to your code, don't stress, a core developer will know these apart.
In the future, if possible, please branch off a passing commit to avoid false positives.
Refer to this link for build results: http://jenkins.saltstack.com/job/salt-pr-build/3363/

[mtorromeo]

Looking at the systemd related bug reports, this should fix #10309 #8444 #11900