* added checks whether OpenDKIM/OpenDMARC/policyd-spf are enabled
* added functions to check if VAR is 0/0 or an int
and also added tests.
I also adjusted the test file to not run in a container, because there
is no need. This also decreases test time, which, in turn, increases
maintainers' happiness.
* added more checks to Rspamd setup
I added the helpers from the previous commit to the Rspamd setup to make
the whole setup more robust, and indicate to the user that an ENV
variable's value is incorrect.
While we did not issues for this in the past, I believe it to be
worthwhile for the future.
* added canonical directory for users to place files in
This dir is canonical with DMS's optional configuration dirs, as it
lives in well-known volume mounts. Hence, users will not need to adjust
`/etc/rspamd/override.d` manually anymore, or mount a volume to this
place.
The docs explain this now, but the DKIM page needs a slight update on
this too I guess. I will follow-up here.
* misc minor improvements
* use variables for common directories
