How to enforce a state only if a minon has SELinux installed?

I have code that installs a custom selinux module. In my fleet of minions there's Fedora-based systems (with SELinux installed) and Debian-based ones (without SELinux ). On the latter the module/installing state should not be used and I am thus looking for a way of retrieving a neat answer to the question "is SELinux installed on this system?" (NOT "is SELinux enforcing on this system?") to use in a corresponding jinja2 if clause.

Attempts that have me despairing are:

there appears to be no state in Salt querying whether a given binary is on the $PATH - checking for sestatus is what I was after here.
salt.states.selinux is not available on systems devoid of SELinux, so its functionality does not help.
I could not find any Salt functionality to query for the local availability of something like salt.states.selinux (see above) either.
Something like
```
- unless: - rpm -q libselinux
```
(from this answer) also does not work, as rpm is Fedora specific...
Checking for absence of /etc/selinux also is not an option, as the Debian systems actually have that.

Any hint on how to go about this is appreciated.

Solution

If selinux is installed, then a grain is available:

{% if 'selinux' in grains %}

# stuff that's only included if selinux is available

{% endif %}

You can also use that grain for minion targeting:

base:
  'selinux:*':
    - match: grain
    - my_states.for_selinux_only

In general, you can also check whether a module has been loaded:

{% if 'selinux.getconfig' in salt %}

Whether an executable is on the PATH:

{% if 'sestatus' | which %}

Whether a package is installed (which also works in an onlyif parameter):

{% if salt['pkg.version']('libselinux') %}