add prometheus metrics to count PE resolving errors

cmd/main.go

@@ -41,6 +41,7 @@ import (
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/config"
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/k8s"
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/policyendpoints"
+	"github.com/aws/amazon-network-policy-controller-k8s/pkg/prometheus"
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/utils/configmap"
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/version"
 	//+kubebuilder:scaffold:imports
@@ -91,6 +92,9 @@ func main() {
 	setupLog.Info("Checking args for policy batch time", "NPBatchTime", controllerCFG.PodUpdateBatchPeriodDuration)
 	setupLog.Info("Checking args for reconciler count", "ReconcilerCount", controllerCFG.MaxConcurrentReconciles)
 
+	setupLog.Info("Register metrics in promethus")
+	prometheus.RegisterPrometheus()
+
 	if controllerCFG.EnableConfigMapCheck {
 		var cancelFn context.CancelFunc
 		ctx, cancelFn = context.WithCancel(ctx)

pkg/policyendpoints/manager.go

@@ -20,6 +20,7 @@ import (
 
 	policyinfo "github.com/aws/amazon-network-policy-controller-k8s/api/v1alpha1"
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/k8s"
+	"github.com/aws/amazon-network-policy-controller-k8s/pkg/prometheus"
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/resolvers"
 )
 
@@ -51,6 +52,7 @@ type policyEndpointsManager struct {
 func (m *policyEndpointsManager) Reconcile(ctx context.Context, policy *networking.NetworkPolicy) error {
 	ingressRules, egressRules, podSelectorEndpoints, err := m.endpointsResolver.Resolve(ctx, policy)
 	if err != nil {
+		prometheus.ResolveNetworkPolicyEndpointsErrCnt.Inc()
 		return err
 	}
 
@@ -107,6 +109,7 @@ func (m *policyEndpointsManager) Cleanup(ctx context.Context, policy *networking
 	if err := m.k8sClient.List(ctx, policyEndpointList,
 		client.InNamespace(policy.Namespace),
 		client.MatchingLabels{IndexKeyPolicyReferenceName: policy.Name}); err != nil {
+		prometheus.CleanupNetworkPolicyEndpointsErrCnt.Inc()
 		return errors.Wrap(err, "unable to list policyendpoints")
 	}
 	for _, policyEndpoint := range policyEndpointList.Items {

pkg/prometheus/metrics.go

@@ -0,0 +1,53 @@
+package prometheus
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
+)
+
+var (
+	CleanupNetworkPolicyEndpointsErrCnt = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "cleanup_network_policy_endpoints_err_count",
+			Help: "The number of errors encountered while cleaning up network policy endpoints",
+		},
+	)
+
+	ResolveNetworkPolicyEndpointsErrCnt = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "resolve_network_policy_endpoints_err_count",
+			Help: "The number of errors encountered while resolving network policy endpoints",
+		},
+	)
+
+	ComputeIngressEndpointsErrCnt = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "compute_ingress_endpoints_err_count",
+			Help: "The number of errors encountered while computing ingress endpoints",
+		},
+	)
+
+	ComputeEgressEndpointsErrCnt = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "compute_egress_endpoints_err_count",
+			Help: "The number of errors encountered while computing egress endpoints",
+		},
+	)
+
+	ComputePodEndpointsErrCnt = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Name: "compute_pod_endpoints_err_count",
+			Help: "The number of errors encountered while computing pod endpoints",
+		},
+	)
+)
+
+func RegisterPrometheus() {
+	metrics.Registry.MustRegister(
+		CleanupNetworkPolicyEndpointsErrCnt,
+		ResolveNetworkPolicyEndpointsErrCnt,
+		ComputeIngressEndpointsErrCnt,
+		ComputeEgressEndpointsErrCnt,
+		ComputePodEndpointsErrCnt,
+	)
+}

pkg/resolvers/endpoints.go

@@ -7,6 +7,7 @@ import (
 
 	policyinfo "github.com/aws/amazon-network-policy-controller-k8s/api/v1alpha1"
 	"github.com/aws/amazon-network-policy-controller-k8s/pkg/k8s"
+	"github.com/aws/amazon-network-policy-controller-k8s/pkg/prometheus"
 	"github.com/go-logr/logr"
 	"github.com/pkg/errors"
 	"golang.org/x/exp/maps"
@@ -44,14 +45,17 @@ func (r *defaultEndpointsResolver) Resolve(ctx context.Context, policy *networki
 	[]policyinfo.EndpointInfo, []policyinfo.PodEndpoint, error) {
 	ingressEndpoints, err := r.computeIngressEndpoints(ctx, policy)
 	if err != nil {
+		prometheus.ComputeIngressEndpointsErrCnt.Inc()
 		return nil, nil, nil, err
 	}
 	egressEndpoints, err := r.computeEgressEndpoints(ctx, policy)
 	if err != nil {
+		prometheus.ComputeEgressEndpointsErrCnt.Inc()
 		return nil, nil, nil, err
 	}
 	podSelectorEndpoints, err := r.computePodSelectorEndpoints(ctx, policy)
 	if err != nil {
+		prometheus.ComputePodEndpointsErrCnt.Inc()
 		return nil, nil, nil, err
 	}
 	r.logger.Info("Resolved endpoints", "policy", k8s.NamespacedName(policy), "ingress", len(ingressEndpoints), "egress",