hyperv: label replica relationships with the VM ID (#2747)

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

internal/collector/hyperv/hyperv_replica_vm.go

@@ -161,7 +161,7 @@ func (c *Collector) buildReplicaVM() error {
 	c.replicaVMHealth = prometheus.NewDesc(
 		prometheus.BuildFQName(types.Namespace, Name, "replica_vm_health"),
 		"The replication health of the virtual machine. 0: Not applicable; 1: OK; 2: Warning; 3: Critical",
-		[]string{"vm", "relationship"},
+		[]string{"vm", "vm_id", "relationship"},
 		nil,
 	)
 	c.replicaVMState = prometheus.NewDesc(
@@ -172,7 +172,7 @@ func (c *Collector) buildReplicaVM() error {
 			"13: Failback in progress; 14: Failback complete; 15: Disk update in progress; 16: Disk update critical; 17: Unknown; "+
 			"18: Repurpose replication in progress; 19: Prepared for sync replication; 20: Prepared for group reverse replication; "+
 			"21: Fire drill in progress",
-		[]string{"vm", "relationship"},
+		[]string{"vm", "vm_id", "relationship"},
 		nil,
 	)
 
@@ -280,13 +280,14 @@ func (c *Collector) collectReplicaVMRelationships(ch chan<- prometheus.Metric, s
 	}
 
 	for _, relationship := range dst {
-		relationshipType := replicationRelationshipType(relationship.InstanceID)
+		vmID, relationshipType := parseReplicationRelationshipID(relationship.InstanceID)
 
 		ch <- scrape.MustNewConstMetric(
 			c.replicaVMHealth,
 			prometheus.GaugeValue,
 			float64(relationship.ReplicationHealth),
 			relationship.ElementName,
+			vmID,
 			relationshipType,
 		)
 
@@ -295,6 +296,7 @@ func (c *Collector) collectReplicaVMRelationships(ch chan<- prometheus.Metric, s
 			prometheus.GaugeValue,
 			float64(relationship.ReplicationState),
 			relationship.ElementName,
+			vmID,
 			relationshipType,
 		)
 	}
@@ -302,16 +304,23 @@ func (c *Collector) collectReplicaVMRelationships(ch chan<- prometheus.Metric, s
 	return nil
 }
 
-// replicationRelationshipType returns the relationship type encoded in the
-// InstanceID ("Microsoft:<vm id>\HVR\<0|1>"). 0 is the primary relationship,
-// 1 the extended replication.
-func replicationRelationshipType(instanceID string) string {
+// parseReplicationRelationshipID returns the ID of the virtual machine and the
+// relationship type encoded in the InstanceID of a replication relationship
+// ("Microsoft:<vm id>\HVR\<0|1>"). The VM ID keeps the series of VMs with the
+// same name apart. Relationship 0 is the primary relationship, 1 the extended
+// replication.
+func parseReplicationRelationshipID(instanceID string) (string, string) {
+	vmID := strings.TrimPrefix(instanceID, "Microsoft:")
+	if i := strings.Index(vmID, `\`); i >= 0 {
+		vmID = vmID[:i]
+	}
+
 	switch instanceID[strings.LastIndex(instanceID, `\`)+1:] {
 	case "0":
-		return "primary"
+		return vmID, "primary"
 	case "1":
-		return "extended"
+		return vmID, "extended"
 	default:
-		return "unknown"
+		return vmID, "unknown"
 	}
 }

internal/collector/hyperv/hyperv_replica_vm_internal_test.go

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+
+package hyperv
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseReplicationRelationshipID(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		instanceID       string
+		vmID             string
+		relationshipType string
+	}{
+		{`Microsoft:6B1F2E1A-3C4D-4E5F-8A9B-0C1D2E3F4A5B\HVR\0`, "6B1F2E1A-3C4D-4E5F-8A9B-0C1D2E3F4A5B", "primary"},
+		{`Microsoft:6B1F2E1A-3C4D-4E5F-8A9B-0C1D2E3F4A5B\HVR\1`, "6B1F2E1A-3C4D-4E5F-8A9B-0C1D2E3F4A5B", "extended"},
+		{`Microsoft:6B1F2E1A-3C4D-4E5F-8A9B-0C1D2E3F4A5B\HVR\2`, "6B1F2E1A-3C4D-4E5F-8A9B-0C1D2E3F4A5B", "unknown"},
+		{`unexpected`, "unexpected", "unknown"},
+		{``, "", "unknown"},
+	} {
+		t.Run(tc.instanceID, func(t *testing.T) {
+			t.Parallel()
+
+			vmID, relationshipType := parseReplicationRelationshipID(tc.instanceID)
+			require.Equal(t, tc.vmID, vmID)
+			require.Equal(t, tc.relationshipType, relationshipType)
+		})
+	}
+}

internal/collector/hyperv/hyperv_test.go

@@ -47,6 +47,9 @@ func TestCollector(t *testing.T) {
 	// The fixture VM is not replicated, but every VM has a primary replication relationship.
 	if metric := testutils.RequireFixtureMetric(t, metrics, hyperv.Name, "windows_hyperv_replica_vm_state", prometheus.Labels{"vm": "GitHubActions", "relationship": "primary"}); metric != nil {
 		require.InDelta(t, 0, metric.GetGauge().GetValue(), 0, "expected replication to be disabled")
+
+		// vm_id keeps VMs with the same name apart; it is the VM's GUID.
+		require.Regexp(t, `^[0-9A-Fa-f-]{36}$`, labelValue(metric, "vm_id"))
 	}
 
 	// The health query reports failures as 0 instead of an error, so check the value.