Refactor kvm resource capacity kpi to use effective capacity (#585)

## Changes
- Adjusted the kvm resource capacity kpi to use the new
`EffectiveCapacity` from the hypervisor CRD, see:
cobaltcore-dev/openstack-hypervisor-operator#257

Author: SoWieMarkus

internal/knowledge/kpis/plugins/compute/resource_capacity_kvm.go

@@ -154,20 +154,30 @@ func (k *KVMResourceCapacityKPI) Collect(ch chan<- prometheus.Metric) {
 	}
 
 	for _, hypervisor := range hvs.Items {
-		cpuTotal, hasCPUTotal := hypervisor.Status.Capacity["cpu"]
-		ramTotal, hasRAMTotal := hypervisor.Status.Capacity["memory"]
+		if hypervisor.Status.EffectiveCapacity == nil {
+			slog.Warn("hypervisor with nil effective capacity, skipping", "host", hypervisor.Name)
+			continue
+		}
+
+		cpuTotal, hasCPUTotal := hypervisor.Status.EffectiveCapacity[hv1.ResourceCPU]
+		ramTotal, hasRAMTotal := hypervisor.Status.EffectiveCapacity[hv1.ResourceMemory]
 
 		if !hasCPUTotal || !hasRAMTotal {
 			slog.Error("hypervisor missing cpu or ram total capacity", "hypervisor", hypervisor.Name)
 			continue
 		}
 
-		cpuUsed, hasCPUUtilized := hypervisor.Status.Allocation["cpu"]
+		if cpuTotal.IsZero() || ramTotal.IsZero() {
+			slog.Warn("hypervisor with zero cpu or ram total capacity, skipping", "host", hypervisor.Name)
+			continue
+		}
+
+		cpuUsed, hasCPUUtilized := hypervisor.Status.Allocation[hv1.ResourceCPU]
 		if !hasCPUUtilized {
 			cpuUsed = resource.MustParse("0")
 		}
 
-		ramUsed, hasRAMUtilized := hypervisor.Status.Allocation["memory"]
+		ramUsed, hasRAMUtilized := hypervisor.Status.Allocation[hv1.ResourceMemory]
 		if !hasRAMUtilized {
 			ramUsed = resource.MustParse("0")
 		}

internal/knowledge/kpis/plugins/compute/resource_capacity_kvm_test.go

@@ -47,6 +47,55 @@ func TestKVMResourceCapacityKPI_Collect(t *testing.T) {
 		hypervisors     []hv1.Hypervisor
 		expectedMetrics map[string][]expectedMetric // metric_name -> []expectedMetric
 	}{
+		{
+			name: "single hypervisor with nil effective capacity",
+			hypervisors: []hv1.Hypervisor{
+				{
+					ObjectMeta: v1.ObjectMeta{
+						Name: "node001-bb088",
+						Labels: map[string]string{
+							"topology.kubernetes.io/zone": "qa-1a",
+						},
+					},
+					Status: hv1.HypervisorStatus{
+						EffectiveCapacity: nil, // Simulate nil effective capacity
+						Allocation: map[hv1.ResourceName]resource.Quantity{
+							hv1.ResourceCPU:    resource.MustParse("64"),
+							hv1.ResourceMemory: resource.MustParse("256Gi"),
+						},
+						Traits: []string{},
+					},
+				},
+			},
+			// No metrics should be emitted for this hypervisor since effective capacity is nil
+			expectedMetrics: map[string][]expectedMetric{},
+		},
+		{
+			name: "single hypervisor with zero total capacity",
+			hypervisors: []hv1.Hypervisor{
+				{
+					ObjectMeta: v1.ObjectMeta{
+						Name: "node001-bb088",
+						Labels: map[string]string{
+							"topology.kubernetes.io/zone": "qa-1a",
+						},
+					},
+					Status: hv1.HypervisorStatus{
+						EffectiveCapacity: map[hv1.ResourceName]resource.Quantity{
+							hv1.ResourceCPU:    resource.MustParse("0"), // Simulate zero CPU capacity
+							hv1.ResourceMemory: resource.MustParse("0"), // Simulate zero RAM capacity
+						},
+						Allocation: map[hv1.ResourceName]resource.Quantity{
+							hv1.ResourceCPU:    resource.MustParse("0"),
+							hv1.ResourceMemory: resource.MustParse("0"),
+						},
+						Traits: []string{},
+					},
+				},
+			},
+			// No metrics should be emitted for this hypervisor since total capacity is zero
+			expectedMetrics: map[string][]expectedMetric{},
+		},
 		{
 			name: "single hypervisor with default traits",
 			hypervisors: []hv1.Hypervisor{
@@ -58,7 +107,7 @@ func TestKVMResourceCapacityKPI_Collect(t *testing.T) {
 						},
 					},
 					Status: hv1.HypervisorStatus{
-						Capacity: map[hv1.ResourceName]resource.Quantity{
+						EffectiveCapacity: map[hv1.ResourceName]resource.Quantity{
 							hv1.ResourceCPU:    resource.MustParse("128"),
 							hv1.ResourceMemory: resource.MustParse("512Gi"),
 						},
@@ -148,7 +197,7 @@ func TestKVMResourceCapacityKPI_Collect(t *testing.T) {
 						},
 					},
 					Status: hv1.HypervisorStatus{
-						Capacity: map[hv1.ResourceName]resource.Quantity{
+						EffectiveCapacity: map[hv1.ResourceName]resource.Quantity{
 							hv1.ResourceCPU:    resource.MustParse("256"),
 							hv1.ResourceMemory: resource.MustParse("1Ti"),
 						},
@@ -209,7 +258,7 @@ func TestKVMResourceCapacityKPI_Collect(t *testing.T) {
 						},
 					},
 					Status: hv1.HypervisorStatus{
-						Capacity: map[hv1.ResourceName]resource.Quantity{
+						EffectiveCapacity: map[hv1.ResourceName]resource.Quantity{
 							hv1.ResourceCPU:    resource.MustParse("64"),
 							hv1.ResourceMemory: resource.MustParse("256Gi"),
 						},
@@ -255,7 +304,7 @@ func TestKVMResourceCapacityKPI_Collect(t *testing.T) {
 						},
 					},
 					Status: hv1.HypervisorStatus{
-						Capacity: map[hv1.ResourceName]resource.Quantity{
+						EffectiveCapacity: map[hv1.ResourceName]resource.Quantity{
 							hv1.ResourceCPU:    resource.MustParse("100"),
 							hv1.ResourceMemory: resource.MustParse("200Gi"),
 						},
@@ -274,7 +323,7 @@ func TestKVMResourceCapacityKPI_Collect(t *testing.T) {
 						},
 					},
 					Status: hv1.HypervisorStatus{
-						Capacity: map[hv1.ResourceName]resource.Quantity{
+						EffectiveCapacity: map[hv1.ResourceName]resource.Quantity{
 							hv1.ResourceCPU:    resource.MustParse("200"),
 							hv1.ResourceMemory: resource.MustParse("400Gi"),
 						},
@@ -332,7 +381,7 @@ func TestKVMResourceCapacityKPI_Collect(t *testing.T) {
 						},
 					},
 					Status: hv1.HypervisorStatus{
-						Capacity: map[hv1.ResourceName]resource.Quantity{
+						EffectiveCapacity: map[hv1.ResourceName]resource.Quantity{
 							hv1.ResourceCPU:    resource.MustParse("96"),
 							hv1.ResourceMemory: resource.MustParse("384Gi"),
 						},