* chore: Remove requirement for `postfix-accounts.cf`
This is an old requirement from when the change detector service was first introduced. It's no longer relevant.
* chore: Do not needlessly create `postfix-aliases.cf`
The config was created regardless to workaround early change detection support. No longer necessary to require the file to exist.
* chore: Drop guards requiring `/tmp/docker-mailserver` to exist
Legacy guards when this was the only location change detection location supported.
There does not appear to be any need for changing into this directory at the start of `check-for-changes.sh` as we use absolute filepaths (originally monitored files were checked with relative paths to this config dir).
* chore: Revise inline docs
* chore: Add change detection monitoring for extra configs
These are also handled at run-time in the current change detection support, so it makes sense to allows these config updates to also trigger change events.
* chore: Extract change-detection method to it's own helper
This doesn't really belong in `helpers/ssl.sh`. Moving to it's own helper script.
* chore: Co-locate related change-detection method from container startup
It seems relevant to migrate the related support during startup for the change detection feature into this helper.
I opted to move the call from `start-mailserver.sh` into the `_setup` call at the end for a more explicit/visible location.
* chore: Move `CHKSUM_FILE` into `helpers/change-detection.sh`
It belongs there, not in `helpers/index.sh`.
* chore: Revise inline documentation
* tests(fix): Ensure correct functionality
Presently `test/test_helper.bats` is using it's own `CHKSUM_FILE` instead of sourcing the var for the filepath.
`test_helper/common.bash` was calling a method to check for changes, but this helper may not correctly detect letsencrypt related changes as these are not ENV rely on, but global vars handled by `helpers/dns.sh`, so that should be run first like it is for `check-for-changes.sh`.
* tests(chore): Use `CHKSUM_FILE` var from helper
* chore: `addmailuser` should use `CHKSUM_FILE` var
* chore: Update `check-for-changes.sh` log message with correct path
