[pkg-go] Bug#921351: Bug#921351: prometheus-postfix-exporter: Init script missing

[Martín Ferrari]

Daniel, et al.


I was preparing a fix for this by copying some support scripts from
other exporters when I noticed a couple of things, and wanted to check
with you before making any change.

This exporter is running with user postfix, while all the others use the
prometheus user. I understand that you need to access the queue
directly, but this could be done by granting the postqueue group when
starting the process instead.

Another thing is that this requires a special log configuration
(duplicating all postfix entries to a new file, and making that file
writable by the user this exporter runs as), which probably should be
documented in a Debian readme, and I have no idea how to do this with
systemd? Also, I'd suggest moving that log to /var/{lib,log}/prometheus


Honestly, back in the day I had looked at this exporter and decided it
was not great because of the log requirement, and started using mtail
for monitoring postfix.