cmd/k8s-operator,k8s-operator,go.mod: optionally create ServiceMonitor (#14248)

* cmd/k8s-operator,k8s-operator,go.mod: optionally create ServiceMonitor

Adds a new spec.metrics.serviceMonitor field to ProxyClass.
If that's set to true (and metrics are enabled), the operator
will create a Prometheus ServiceMonitor for each proxy to which
the ProxyClass applies.
Additionally, create a metrics Service for each proxy that has
metrics enabled.

Updates tailscale/tailscale#11292

Signed-off-by: Irbe Krumina <irbe@tailscale.com>

cmd/k8s-operator/ingress_test.go

@@ -12,6 +12,7 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	networkingv1 "k8s.io/api/networking/v1"
+	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"sigs.k8s.io/controller-runtime/pkg/client/fake"
@@ -271,3 +272,124 @@ func TestTailscaleIngressWithProxyClass(t *testing.T) {
 	opts.proxyClass = ""
 	expectEqual(t, fc, expectedSTSUserspace(t, fc, opts), removeHashAnnotation)
 }
+
+func TestTailscaleIngressWithServiceMonitor(t *testing.T) {
+	pc := &tsapi.ProxyClass{
+		ObjectMeta: metav1.ObjectMeta{Name: "metrics", Generation: 1},
+		Spec: tsapi.ProxyClassSpec{
+			Metrics: &tsapi.Metrics{
+				Enable:         true,
+				ServiceMonitor: &tsapi.ServiceMonitor{Enable: true},
+			},
+		},
+		Status: tsapi.ProxyClassStatus{
+			Conditions: []metav1.Condition{{
+				Status:             metav1.ConditionTrue,
+				Type:               string(tsapi.ProxyClassReady),
+				ObservedGeneration: 1,
+			}}},
+	}
+	crd := &apiextensionsv1.CustomResourceDefinition{ObjectMeta: metav1.ObjectMeta{Name: serviceMonitorCRD}}
+	tsIngressClass := &networkingv1.IngressClass{ObjectMeta: metav1.ObjectMeta{Name: "tailscale"}, Spec: networkingv1.IngressClassSpec{Controller: "tailscale.com/ts-ingress"}}
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(pc, tsIngressClass).
+		WithStatusSubresource(pc).
+		Build()
+	ft := &fakeTSClient{}
+	fakeTsnetServer := &fakeTSNetServer{certDomains: []string{"foo.com"}}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ingR := &IngressReconciler{
+		Client: fc,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			tsnetServer:       fakeTsnetServer,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger: zl.Sugar(),
+	}
+	// 1. Enable metrics- expect metrics Service to be created
+	ing := &networkingv1.Ingress{
+		TypeMeta: metav1.TypeMeta{Kind: "Ingress", APIVersion: "networking.k8s.io/v1"},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+			Labels: map[string]string{
+				"tailscale.com/proxy-class": "metrics",
+			},
+		},
+		Spec: networkingv1.IngressSpec{
+			IngressClassName: ptr.To("tailscale"),
+			DefaultBackend: &networkingv1.IngressBackend{
+				Service: &networkingv1.IngressServiceBackend{
+					Name: "test",
+					Port: networkingv1.ServiceBackendPort{
+						Number: 8080,
+					},
+				},
+			},
+			TLS: []networkingv1.IngressTLS{
+				{Hosts: []string{"default-test"}},
+			},
+		},
+	}
+	mustCreate(t, fc, ing)
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "1.2.3.4",
+			Ports: []corev1.ServicePort{{
+				Port: 8080,
+				Name: "http"},
+			},
+		},
+	})
+
+	expectReconciled(t, ingR, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test", "ingress")
+	opts := configOpts{
+		stsName:            shortName,
+		secretName:         fullName,
+		namespace:          "default",
+		tailscaleNamespace: "operator-ns",
+		parentType:         "ingress",
+		hostname:           "default-test",
+		app:                kubetypes.AppIngressResource,
+		enableMetrics:      true,
+		namespaced:         true,
+		proxyType:          proxyTypeIngressResource,
+	}
+	serveConfig := &ipn.ServeConfig{
+		TCP: map[uint16]*ipn.TCPPortHandler{443: {HTTPS: true}},
+		Web: map[ipn.HostPort]*ipn.WebServerConfig{"${TS_CERT_DOMAIN}:443": {Handlers: map[string]*ipn.HTTPHandler{"/": {Proxy: "http://1.2.3.4:8080/"}}}},
+	}
+	opts.serveConfig = serveConfig
+
+	expectEqual(t, fc, expectedSecret(t, fc, opts), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "ingress"), nil)
+	expectEqual(t, fc, expectedMetricsService(opts), nil)
+	expectEqual(t, fc, expectedSTSUserspace(t, fc, opts), removeHashAnnotation)
+	// 2. Enable ServiceMonitor - should not error when there is no ServiceMonitor CRD in cluster
+	mustUpdate(t, fc, "", "metrics", func(pc *tsapi.ProxyClass) {
+		pc.Spec.Metrics.ServiceMonitor = &tsapi.ServiceMonitor{Enable: true}
+	})
+	expectReconciled(t, ingR, "default", "test")
+	// 3. Create ServiceMonitor CRD and reconcile- ServiceMonitor should get created
+	mustCreate(t, fc, crd)
+	expectReconciled(t, ingR, "default", "test")
+	expectEqualUnstructured(t, fc, expectedServiceMonitor(t, opts))
+}