Introduce a new metric cluster_version_risk_conditions

Follow up [1].

The samples for `cluster_version_risk_conditions` will be collected
only when its operator `shouldReconcileAcceptRisks`. It means, e.g.,
on a TechPreview disabled cluster the metric is still defined but
has no samples.

[1]. #1284 (comment)

Author: hongkailiu

pkg/cvo/metrics.go

@@ -14,6 +14,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apiserver/pkg/server/dynamiccertificates"
@@ -52,6 +53,7 @@ type operatorMetrics struct {
 	capability                                            *prometheus.GaugeVec
 	clusterOperatorUp                                     *prometheus.GaugeVec
 	clusterOperatorConditions                             *prometheus.GaugeVec
+	clusterVersionRiskConditions                          *prometheus.GaugeVec
 	clusterOperatorConditionTransitions                   *prometheus.GaugeVec
 	clusterInstaller                                      *prometheus.GaugeVec
 	clusterVersionOperatorUpdateRetrievalTimestampSeconds *prometheus.GaugeVec
@@ -102,6 +104,10 @@ penultimate completed version for 'completed'.
 			Name: "cluster_operator_conditions",
 			Help: "Report the conditions for active cluster operators. 0 is False and 1 is True.",
 		}, []string{"name", "condition", "reason"}),
+		clusterVersionRiskConditions: prometheus.NewGaugeVec(prometheus.GaugeOpts{
+			Name: "cluster_version_risk_conditions",
+			Help: "Report the risk conditions for cluster versions. 0 is False and 1 is True.",
+		}, []string{"name", "condition", "risk"}),
 		clusterOperatorConditionTransitions: prometheus.NewGaugeVec(prometheus.GaugeOpts{
 			Name: "cluster_operator_condition_transitions",
 			Help: "Reports the number of times that a condition on a cluster operator changes status",
@@ -487,6 +493,7 @@ func (m *operatorMetrics) Describe(ch chan<- *prometheus.Desc) {
 	ch <- m.capability.WithLabelValues("").Desc()
 	ch <- m.clusterOperatorUp.WithLabelValues("", "", "").Desc()
 	ch <- m.clusterOperatorConditions.WithLabelValues("", "", "").Desc()
+	ch <- m.clusterVersionRiskConditions.WithLabelValues("", "", "").Desc()
 	ch <- m.clusterOperatorConditionTransitions.WithLabelValues("", "").Desc()
 	ch <- m.clusterInstaller.WithLabelValues("", "", "").Desc()
 	ch <- m.clusterVersionOperatorUpdateRetrievalTimestampSeconds.WithLabelValues("").Desc()
@@ -508,6 +515,24 @@ func (m *operatorMetrics) collectConditionalUpdates(ch chan<- prometheus.Metric,
 	}
 }
 
+func (m *operatorMetrics) collectConditionalUpdateRisks(ch chan<- prometheus.Metric, risks []configv1.ConditionalUpdateRisk) {
+	for _, risk := range risks {
+		for _, condition := range risk.Conditions {
+			if condition.Type != internal.ConditionalUpdateRiskConditionTypeApplies {
+				continue
+			}
+
+			g := m.clusterVersionRiskConditions.WithLabelValues("version", condition.Type, risk.Name)
+			if condition.Status == metav1.ConditionTrue {
+				g.Set(1)
+			} else {
+				g.Set(0)
+			}
+			ch <- g
+		}
+	}
+}
+
 // Collect collects metrics from the operator into the channel ch
 func (m *operatorMetrics) Collect(ch chan<- prometheus.Metric) {
 	current := m.optr.currentVersion()
@@ -653,6 +678,9 @@ func (m *operatorMetrics) Collect(ch chan<- prometheus.Metric) {
 		}
 
 		m.collectConditionalUpdates(ch, cv.Status.ConditionalUpdates)
+		if m.optr.shouldReconcileAcceptRisks() {
+			m.collectConditionalUpdateRisks(ch, cv.Status.ConditionalUpdateRisks)
+		}
 	}
 
 	g := m.version.WithLabelValues("current", current.Version, current.Image, completed.Version)

pkg/cvo/metrics_test.go

@@ -23,6 +23,7 @@ import (
 	"k8s.io/apiserver/pkg/server/dynamiccertificates"
 	"k8s.io/client-go/tools/record"
 
+	"github.com/openshift/cluster-version-operator/pkg/featuregates"
 	"github.com/openshift/cluster-version-operator/pkg/internal"
 )
 
@@ -667,6 +668,7 @@ func Test_operatorMetrics_Collect(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			tt.optr.enabledCVOFeatureGates = featuregates.DefaultCvoGates("version")
 			tt.optr.eventRecorder = record.NewFakeRecorder(100)
 			if tt.optr.cvLister == nil {
 				tt.optr.cvLister = &cvLister{}
@@ -973,6 +975,116 @@ func TestCollectUnknownConditionalUpdates(t *testing.T) {
 	}
 }
 
+func Test_collectConditionalUpdateRisks(t *testing.T) {
+	type valueWithLabels struct {
+		value  float64
+		labels map[string]string
+	}
+	testCases := []struct {
+		name     string
+		risks    []configv1.ConditionalUpdateRisk
+		expected []valueWithLabels
+	}{
+		{
+			name:     "no conditional updates",
+			expected: []valueWithLabels{},
+		},
+		{
+			name: "unknown type",
+			risks: []configv1.ConditionalUpdateRisk{
+				{
+					Name: "RiskX",
+					Conditions: []metav1.Condition{{
+						Type:    internal.ConditionalUpdateConditionTypeRecommended,
+						Status:  metav1.ConditionFalse,
+						Reason:  "ReasonA",
+						Message: "Risk does not apply",
+					}},
+				},
+			},
+		},
+		{
+			name: "apply false",
+			risks: []configv1.ConditionalUpdateRisk{
+				{
+					Name: "RiskX",
+					Conditions: []metav1.Condition{{
+						Type:    internal.ConditionalUpdateRiskConditionTypeApplies,
+						Status:  metav1.ConditionFalse,
+						Reason:  "ReasonA",
+						Message: "Risk does not apply",
+					}},
+				},
+			},
+			expected: []valueWithLabels{{
+				labels: map[string]string{"name": "version", "condition": "Applies", "risk": "RiskX"},
+			}},
+		},
+		{
+			name: "apply true",
+			risks: []configv1.ConditionalUpdateRisk{
+				{
+					Name: "RiskX",
+					Conditions: []metav1.Condition{{
+						Type:    internal.ConditionalUpdateRiskConditionTypeApplies,
+						Status:  metav1.ConditionTrue,
+						Reason:  "ReasonA",
+						Message: "Risk does not apply",
+					}},
+				},
+			},
+			expected: []valueWithLabels{{
+				value:  1,
+				labels: map[string]string{"name": "version", "condition": "Applies", "risk": "RiskX"},
+			}},
+		},
+		{
+			name: "apply unknown",
+			risks: []configv1.ConditionalUpdateRisk{
+				{
+					Name: "RiskX",
+					Conditions: []metav1.Condition{{
+						Type:    internal.ConditionalUpdateRiskConditionTypeApplies,
+						Status:  metav1.ConditionUnknown,
+						Reason:  "ReasonA",
+						Message: "Risk does not apply",
+					}},
+				},
+			},
+			expected: []valueWithLabels{{
+				labels: map[string]string{"name": "version", "condition": "Applies", "risk": "RiskX"},
+			}},
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			optr := &Operator{}
+			m := newOperatorMetrics(optr)
+			ch := make(chan prometheus.Metric)
+
+			go func() {
+				m.collectConditionalUpdateRisks(ch, tc.risks)
+				close(ch)
+			}()
+
+			var collected []prometheus.Metric
+			for item := range ch {
+				collected = append(collected, item)
+			}
+
+			if lenC, lenE := len(collected), len(tc.expected); lenC != lenE {
+
+				t.Fatalf("Expected %d metrics, got %d metrics\nGot metrics: %s", lenE, lenC, spew.Sdump(collected))
+			}
+			for i := range tc.expected {
+				expectMetric(t, collected[i], tc.expected[i].value, tc.expected[i].labels)
+			}
+		})
+	}
+}
+
 func expectMetric(t *testing.T, metric prometheus.Metric, value float64, labels map[string]string) {
 	t.Helper()
 	var d dto.Metric