pkg/{sdk,generator} Expose Prometheus metrics port

Author: etiennecoutaud

pkg/generator/generator.go

@@ -23,6 +23,8 @@ import (
 	"path/filepath"
 	"strings"
 	"text/template"
+
+	k8sutil "github.com/operator-framework/operator-sdk/pkg/util/k8sutil"
 )
 
 const (
@@ -237,8 +239,11 @@ func renderDeployFiles(deployDir, projectName, apiVersion, kind string) error {
 // RenderOperatorYaml generates "deploy/operator.yaml"
 func RenderOperatorYaml(c *Config, image string) error {
 	td := tmplData{
-		ProjectName: c.ProjectName,
-		Image:       image,
+		ProjectName:     c.ProjectName,
+		Image:           image,
+		MetricsPort:     k8sutil.PrometheusMetricsPort,
+		MetricsPortName: k8sutil.PrometheusMetricsPortName,
+		OperatorNameEnv: k8sutil.OperatorNameEnvVar,
 	}
 	return renderWriteFile(operatorYaml, operatorTmplName, operatorYamlTmpl, td)
 }
@@ -443,8 +448,11 @@ type tmplData struct {
 	// plural name to be used in the URL: /apis/<group>/<version>/<plural>
 	KindPlural string
 
-	Image string
-	Name  string
+	Image           string
+	Name            string
+	MetricsPort     int
+	MetricsPortName string
+	OperatorNameEnv string
 
 	PackageName string
 	ChannelName string

pkg/generator/generator_test.go

@@ -20,6 +20,7 @@ import (
 	"strings"
 	"testing"
 
+	k8sutil "github.com/operator-framework/operator-sdk/pkg/util/k8sutil"
 	"github.com/sergi/go-diff/diffmatchpatch"
 )
 
@@ -199,6 +200,9 @@ spec:
       containers:
         - name: app-operator
           image: quay.io/example-inc/app-operator:0.0.1
+          ports:
+          - containerPort: 60000
+            name: metrics
           command:
           - app-operator
           imagePullPolicy: Always
@@ -207,6 +211,8 @@ spec:
               valueFrom:
                 fieldRef:
                   fieldPath: metadata.namespace
+            - name: OPERATOR_NAME
+              value: "app-operator"
 `
 
 const rbacYamlExp = `kind: Role
@@ -276,7 +282,7 @@ func TestGenDeploy(t *testing.T) {
 	}
 
 	buf = &bytes.Buffer{}
-	if err := renderFile(buf, operatorTmplName, operatorYamlTmpl, tmplData{ProjectName: appProjectName, Image: appImage}); err != nil {
+	if err := renderFile(buf, operatorTmplName, operatorYamlTmpl, tmplData{ProjectName: appProjectName, Image: appImage, MetricsPort: k8sutil.PrometheusMetricsPort, MetricsPortName: k8sutil.PrometheusMetricsPortName, OperatorNameEnv: k8sutil.OperatorNameEnvVar}); err != nil {
 		t.Error(err)
 	}
 	if operatorYamlExp != buf.String() {
@@ -423,6 +429,8 @@ func printVersion() {
 func main() {
 	printVersion()
 
+	sdk.ExposeMetricsPort()
+
 	resource := "app.example.com/v1alpha1"
 	kind := "AppService"
 	namespace, err := k8sutil.GetWatchNamespace()

pkg/generator/templates.go

@@ -150,6 +150,8 @@ func printVersion() {
 func main() {
 	printVersion()
 
+	sdk.ExposeMetricsPort()
+
 	resource := "{{.APIVersion}}"
 	kind := "{{.Kind}}"
 	namespace, err := k8sutil.GetWatchNamespace()
@@ -417,6 +419,9 @@ spec:
       containers:
         - name: {{.ProjectName}}
           image: {{.Image}}
+          ports:
+          - containerPort: {{.MetricsPort}}
+            name: {{.MetricsPortName}}
           command:
           - {{.ProjectName}}
           imagePullPolicy: Always
@@ -425,6 +430,8 @@ spec:
               valueFrom:
                 fieldRef:
                   fieldPath: metadata.namespace
+            - name: {{.OperatorNameEnv}}
+              value: "{{.ProjectName}}"
 `
 
 const rbacYamlTmpl = `kind: Role

pkg/sdk/metrics.go

@@ -0,0 +1,28 @@
+package sdk
+
+import (
+	"net/http"
+	"strconv"
+
+	k8sutil "github.com/operator-framework/operator-sdk/pkg/util/k8sutil"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/sirupsen/logrus"
+	"k8s.io/apimachinery/pkg/api/errors"
+)
+
+// ExposeMetricsPort generate a Kubernetes Service to expose metrics port
+func ExposeMetricsPort() {
+	http.Handle("/"+k8sutil.PrometheusMetricsPortName, promhttp.Handler())
+	go http.ListenAndServe(":"+strconv.Itoa(k8sutil.PrometheusMetricsPort), nil)
+
+	service, err := k8sutil.InitOperatorService()
+	if err != nil {
+		logrus.Fatalf("Failed to init operator service: %v", err)
+	}
+	err = Create(service)
+	if err != nil && !errors.IsAlreadyExists(err) {
+		logrus.Infof("Failed to create operator service: %v", err)
+		return
+	}
+	logrus.Infof("Metrics service %s created", service.Name)
+}

pkg/util/k8sutil/constants.go

@@ -8,4 +8,14 @@ const (
 	// WatchNamespaceEnvVar is the constant for env variable WATCH_NAMESPACE
 	// which is the namespace that the pod is currently running in.
 	WatchNamespaceEnvVar = "WATCH_NAMESPACE"
+
+	// OperatorNameEnvVar is the constant for env variable OPERATOR_NAME
+	// wich is the name of the current operator
+	OperatorNameEnvVar = "OPERATOR_NAME"
+
+	// PrometheusMetricsPort defines the port which expose prometheus metrics
+	PrometheusMetricsPort = 60000
+
+	// PrometheusMetricsPortName define the port name used in kubernetes deployment and service
+	PrometheusMetricsPortName = "metrics"
 )

pkg/util/k8sutil/k8sutil.go

@@ -19,12 +19,14 @@ import (
 	"fmt"
 	"os"
 
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
+	intstr "k8s.io/apimachinery/pkg/util/intstr"
 	cgoscheme "k8s.io/client-go/kubernetes/scheme"
 )
 
@@ -147,3 +149,53 @@ func GetWatchNamespace() (string, error) {
 	}
 	return ns, nil
 }
+
+// GetOperatorName return the operator name
+func GetOperatorName() (string, error) {
+	operatorName, found := os.LookupEnv(OperatorNameEnvVar)
+	if !found {
+		return "", fmt.Errorf("%s must be set", OperatorNameEnvVar)
+	}
+	if len(operatorName) == 0 {
+		return "", fmt.Errorf("%s must not be empty", OperatorNameEnvVar)
+	}
+	return operatorName, nil
+}
+
+// InitOperatorService return the static service which expose operator metrics
+func InitOperatorService() (*v1.Service, error) {
+	operatorName, err := GetOperatorName()
+	if err != nil {
+		return nil, err
+	}
+	namespace, err := GetWatchNamespace()
+	if err != nil {
+		return nil, err
+	}
+	service := &v1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      operatorName,
+			Namespace: namespace,
+			Labels:    map[string]string{"name": operatorName},
+		},
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "v1",
+		},
+		Spec: v1.ServiceSpec{
+			Ports: []v1.ServicePort{
+				{
+					Port:     PrometheusMetricsPort,
+					Protocol: v1.ProtocolTCP,
+					TargetPort: intstr.IntOrString{
+						Type:   intstr.String,
+						StrVal: PrometheusMetricsPortName,
+					},
+					Name: PrometheusMetricsPortName,
+				},
+			},
+			Selector: map[string]string{"name": operatorName},
+		},
+	}
+	return service, nil
+}

pkg/util/k8sutil/k8sutil_test.go

@@ -0,0 +1,61 @@
+package k8sutil
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"testing"
+)
+
+func TestGetOperatorName(t *testing.T) {
+	type Output struct {
+		operatorName string
+		err          error
+	}
+
+	type Scenario struct {
+		name           string
+		envVarKey      string
+		envVarValue    string
+		expectedOutput Output
+	}
+
+	tests := []Scenario{
+		Scenario{
+			name:        "Simple case",
+			envVarKey:   OperatorNameEnvVar,
+			envVarValue: "myoperator",
+			expectedOutput: Output{
+				operatorName: "myoperator",
+				err:          nil,
+			},
+		},
+		Scenario{
+			name:        "Unset env var",
+			envVarKey:   "",
+			envVarValue: "",
+			expectedOutput: Output{
+				operatorName: "",
+				err:          fmt.Errorf("%s must be set", OperatorNameEnvVar),
+			},
+		},
+		Scenario{
+			name:        "Empty env var",
+			envVarKey:   OperatorNameEnvVar,
+			envVarValue: "",
+			expectedOutput: Output{
+				operatorName: "",
+				err:          fmt.Errorf("%s must not be empty", OperatorNameEnvVar),
+			},
+		},
+	}
+
+	for _, test := range tests {
+		_ = os.Setenv(test.envVarKey, test.envVarValue)
+		operatorName, err := GetOperatorName()
+		if !(operatorName == test.expectedOutput.operatorName && reflect.DeepEqual(err, test.expectedOutput.err)) {
+			t.Errorf("test %s failed, expected ouput: %s,%v; got: %s,%v", test.name, test.expectedOutput.operatorName, test.expectedOutput.err, operatorName, err)
+		}
+		_ = os.Unsetenv(test.envVarKey)
+	}
+}