Adds a new `unas` input plugin that polls UNAS Pro storage consoles and
exports console health, storage pools, disks and shares to Prometheus,
InfluxDB and DataDog.
UNAS is a separate plugin rather than a device type inside inputunifi
because a storage-only console has no Network application: it cannot
answer /status, has no sites, and shares none of the UniFi device schema.
The plugin is opt-in and inert until an operator names a console. Opt-in
is expressed as "no devices configured" rather than a `disable` flag,
because a bool named `disable` zero-values to false and so cannot make a
plugin default-off. Initialize returns silently on an empty device list
and, unlike inputunifi, nothing synthesizes a default URL.
Two behaviours are worth calling out for reviewers:
- Metrics returns (metrics, nil) whenever any console was collected.
poller.collectMetrics uses `if err != nil {} else if metric != nil`,
so returning both would discard every healthy console because one
failed. Only a total failure returns an error.
- Re-auth fires on total failure, not on a 401. A mid-session 401 from
GetData surfaces as ErrInvalidStatusCode, not ErrAuthenticationFailed,
so there is no sentinel to match on. Session expiry fails all four
endpoints at once, which is exactly the total-failure case.
Prometheus metrics use the `unifi_unas_` prefix, which diverges from the
`unas_` prefix used by the reference implementation; dashboards built
against that will need query edits.
Requires unifi/v5 v5.31.0 for the UNAS client and structs.
Credit to alexgreenbank/unaspoller for mapping the endpoints.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
