Allows shipping snapshots automatically to remote clusters on a cron,
identically to how autobackup handles local snapshot exports.
VMs are selected based on configured tags, and individual destination
clusters can be specified based on a colon-separated suffix to the
tag(s).
Automirror snapshots use the prefix "am" (analogous to "ab" for
autobackups) to differentiate them from normal "mr" mirrors.
Moves VM autobackups from being in-CLI to being handled by the
pvcworkerd system on the primary coordinator. Turns the CLI autobackup
command into an actual API client endpoint rather than having its logic
in the CLI.
In addition, modifies the new autobackup to leverage the new "pvc vm
snapshot" function set, just with special snapshot names. This helps
automate this within the new snapshot scaffolding.
Since these are unauthenticated, it might be the case that an
administrator wishes to completely disable these metrics endpoints.
Provide that option via pvc.conf through pvc-ansible's existing
enable_prometheus_exporters option and the new enable_prometheus
configuration flag.
Defaults to "yes" to provide all functionality unless explicitly
disabled, as the author assumes that the PVC API is secured in other
ways as well and that metric information is not completely sensitive.
