add further missing cinder disk states (#10)

* add further missing states

Complete list of available Cinder states from upstream API code. Also
simplified `CinderDiskStuck` alert to match all disks stuck in
transitional states (all but available and in-use) instead of explicitly
listing them.

* error-state have underscores, not hyphens

Co-Authored-By: Christian Schlotter <[email protected]>

Author: JensErat

docs/alerts.md

@@ -7,7 +7,7 @@ This alerts assume that the parameter `metrics-prefix` was not changed and still
 
 ```
   - alert: CinderDiskStuck
-    expr: kos_cinder_volume_status{status=~".*ing"} == 1
+    expr: kos_cinder_volume_status{status!~"available|in-use"} == 1
     for: 30m
     labels:
       severity: critical

pkg/metrics/cinder.go

@@ -20,8 +20,8 @@ var (
 	// labels which get applied to the most metrics
 	defaultLabels = []string{"id", "description", "name", "status", "cinder_availability_zone", "volume_type", "pvc_name", "pvc_namespace", "pv_name", "pv_storage_class", "pv_reclaim_policy", "pv_fs_type"}
 
-	// possible cinder states
-	cinderStates = []string{"available", "error", "creating", "deleting", "in-use", "attaching", "detaching", "error_deleting", "maintenance", "reserved"}
+	// possible cinder states, from https://github.com/openstack/cinder/blob/master/cinder/objects/fields.py#L168
+	cinderStates = []string{"creating", "available", "deleting", "error", "error_deleting", "error_managing", "managing", "attaching", "in-use", "detaching", "maintenance", "restoring-backup", "error_restoring", "reserved", "awaiting-transfer", "backing-up", "error_backing-up", "error_extending", "downloading", "uploading", "retyping", "extending"}
 
 	cinderQuotaVolumes         *prometheus.GaugeVec
 	cinderQuotaVolumesGigabyte *prometheus.GaugeVec