This option allows basic configuration of the compression technique
used in the backup script. Specifically it adds `none` and `zstd` as
new alternatives, keeping `gzip` as the default.
When sending or receiving datasets with the old implementation it
wouldn't matter which dataset we were sending or receiving, we would
always delegate permissions to the entire pool.
Previously, a failed backup would always overwrite ${db}.sql.gz,
because the bash `>` redirect truncates the file; even if the
backup was going to fail.
On the next run, the ${db}.prev.sql.gz backup would be
overwritten by the bad ${db}.sql.gz.
Now, if the backup fails, the ${db}.in-progress.sql.gz is in an
unknown state, but ${db}.sql.gz will not be written.
On the next run, ${db}.prev.sql.gz (our only good backup) will
not be overwritten because ${db}.sql.gz does not exist.
Or … none! Because forcing a string always results in an OnCalender=
setting, but an empty string leads to an empty value.
> postgresqlBackup-hass.timer: Timer unit lacks value setting. Refusing.
or
> postgresqlBackup-miniflux.timer: Cannot add dependency job, ignoring: Unit postgresqlBackup-miniflux.timer has a bad unit file setting.
I require the postgresqlBackup in my borgbackup unit, so I don't
strictly need the timer and could previously set it to an empty list.
Current module add backups forever, with no way to prune old ones.
Add an option to remove backups after n full backups or after some
amount of time.
Also run duplicity cleanup to clean unused files in case some previous
backup was improperly interrupted.
As the only consequence of isSystemUser is that if the uid is null then
it's allocated below 500, if a user has uid = something below 500 then
we don't require isSystemUser to be set.
Motivation: https://github.com/NixOS/nixpkgs/issues/112647
By default, restic determines the location of the cache based on the XDG
base dir specification, which is `~/.cache/restic` when the environment
variable `$XDG_CACHE_HOME` isn't set.
As restic is executed as root by default, this resulted in the cache being
written to `/root/.cache/restic`, which is not quite right for a system
service and also meant, multiple backup services would use the same cache
directory - potentially causing issues with locking, data corruption,
etc.
The goal was to ensure, restic uses the correct cache location for a
system service - one cache per backup specification, using `/var/cache`
as the base directory for it.
systemd sets the environment variable `$CACHE_DIRECTORY` once
`CacheDirectory=` is defined, but restic doesn't change its behavior
based on the presence of this environment variable.
Instead, the specifier [1] `%C` can be used to point restic explicitly
towards the correct cache location using the `--cache-dir` argument.
Furthermore, the `CacheDirectoryMode=` was set to `0700`, as the default
of `0755` is far too open in this case, as the cache might contain
sensitive data.
[1] https://www.freedesktop.org/software/systemd/man/systemd.unit.html#Specifiers
After 733acfa140d5b73bc69c53c4ebd90ccc5f281f0e, syncoid would fail to
run if commonArgs did not include [ "--no-sync-snap" ], since it would
not have permissions to create or destroy snapshots.
