Fix prometheus port and add unit test for opentelemetry (#1093)

* Disable prometheus port when not allowed (#1078) and add unit test for opentelemetry (#1088)

pkg/observability/opentelemetry.go

@@ -16,7 +16,9 @@ package observability
 import (
 	"context"
 	"fmt"
+	"net"
 	"net/http"
+	"strconv"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -36,6 +38,7 @@ var (
 	labelNodeStatusKey = attribute.Key("node/status")
 	labelNodeNameKey   = attribute.Key("node/name")
 	labelEventIDKey    = attribute.Key("node/event-id")
+	metricsEndpoint    = "/metrics"
 )
 
 // Metrics represents the stats for observability
@@ -62,13 +65,14 @@ func InitMetrics(enabled bool, port int) (Metrics, error) {
 
 	// Starts an async process to collect golang runtime stats
 	// go.opentelemetry.io/contrib/instrumentation/runtime
-	if err = runtime.Start(
-		runtime.WithMeterProvider(provider),
-		runtime.WithMinimumReadMemStatsInterval(1*time.Second)); err != nil {
+	err = runtime.Start(runtime.WithMeterProvider(provider), runtime.WithMinimumReadMemStatsInterval(1*time.Second))
+	if err != nil {
 		return Metrics{}, fmt.Errorf("failed to start Go runtime metrics collection: %w", err)
 	}
 
-	go serveMetrics(port)
+	if enabled {
+		serveMetrics(port)
+	}
 
 	return metrics, nil
 }
@@ -135,10 +139,19 @@ func registerMetricsWith(provider *metric.MeterProvider) (Metrics, error) {
 	}, nil
 }
 
-func serveMetrics(port int) {
-	log.Info().Msgf("Starting to serve handler /metrics, port %d", port)
-	http.Handle("/metrics", promhttp.Handler())
-	if err := http.ListenAndServe(fmt.Sprintf(":%d", port), nil); err != nil {
-		log.Err(err).Msg("Failed to listen and serve http server")
+func serveMetrics(port int) *http.Server {
+	http.Handle(metricsEndpoint, promhttp.Handler())
+
+	server := &http.Server{
+		Addr: net.JoinHostPort("", strconv.Itoa(port)),
 	}
+
+	go func() {
+		log.Info().Msgf("Starting to serve handler %s, port %d", metricsEndpoint, port)
+		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Err(err).Msg("Failed to listen and serve http server")
+		}
+	}()
+
+	return server
 }

pkg/observability/opentelemetry_test.go

@@ -0,0 +1,244 @@
+// Copyright 2016-2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//     http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
+package observability
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	api "go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/sdk/metric"
+
+	h "github.com/aws/aws-node-termination-handler/pkg/test"
+)
+
+var (
+	mockNth         = "aws.node.termination.handler"
+	mockErrorEvent  = "mockErrorEvent"
+	mockAction      = "cordon-and-drain"
+	mockNodeName1   = "nodeName1"
+	mockNodeName2   = "nodeName2"
+	mockNodeName3   = "nodeName3"
+	mockEventID1    = "eventID1"
+	mockEventID2    = "eventID2"
+	mockEventID3    = "eventID3"
+	successStatus   = "success"
+	errorStatus     = "error"
+	mockDefaultPort = 9092
+	mockClosedPort  = 9093
+)
+
+func TestInitMetrics(t *testing.T) {
+	getMetrics(t)
+
+	responseRecorder := mockMetricsRequest()
+
+	validateStatus(t, responseRecorder)
+
+	metricsMap := getMetricsMap(responseRecorder.Body.String())
+
+	runtimeMetrics := []string{
+		"go_gc_gogc_percent",
+		"go_memstats_frees_total",
+		"go_goroutines",
+	}
+
+	for _, metricName := range runtimeMetrics {
+		_, exists := metricsMap[metricName]
+		h.Assert(t, exists, fmt.Sprintf("%v metric should be present", metricName))
+	}
+}
+
+func TestErrorEventsInc(t *testing.T) {
+	metrics := getMetrics(t)
+
+	metrics.ErrorEventsInc(mockErrorEvent)
+
+	responseRecorder := mockMetricsRequest()
+
+	validateStatus(t, responseRecorder)
+
+	metricsMap := getMetricsMap(responseRecorder.Body.String())
+
+	validateEventErrorTotal(t, metricsMap, 1)
+	validateActionTotalV2(t, metricsMap, 0, successStatus)
+	validateActionTotalV2(t, metricsMap, 0, errorStatus)
+}
+
+func TestNodeActionsInc(t *testing.T) {
+	metrics := getMetrics(t)
+
+	metrics.NodeActionsInc(mockAction, mockNodeName1, mockEventID1, nil)
+	metrics.NodeActionsInc(mockAction, mockNodeName2, mockEventID2, nil)
+	metrics.NodeActionsInc(mockAction, mockNodeName3, mockEventID3, errors.New("mockError"))
+
+	responseRecorder := mockMetricsRequest()
+
+	validateStatus(t, responseRecorder)
+
+	metricsMap := getMetricsMap(responseRecorder.Body.String())
+
+	validateEventErrorTotal(t, metricsMap, 0)
+	validateActionTotalV2(t, metricsMap, 2, successStatus)
+	validateActionTotalV2(t, metricsMap, 1, errorStatus)
+}
+
+func TestRegisterMetricsWith(t *testing.T) {
+	const errorEventMetricsTotal = 23
+	const successActionMetricsTotal = 31
+	const errorActionMetricsTotal = 97
+
+	metrics := getMetrics(t)
+
+	errorEventlabels := []attribute.KeyValue{labelEventErrorWhereKey.String(mockErrorEvent)}
+	successActionlabels := []attribute.KeyValue{labelNodeActionKey.String(mockAction), labelNodeStatusKey.String(successStatus)}
+	errorActionlabels := []attribute.KeyValue{labelNodeActionKey.String(mockAction), labelNodeStatusKey.String(errorStatus)}
+
+	for i := 0; i < errorEventMetricsTotal; i++ {
+		metrics.errorEventsCounter.Add(context.Background(), 1, api.WithAttributes(errorEventlabels...))
+	}
+	for i := 0; i < successActionMetricsTotal; i++ {
+		metrics.actionsCounterV2.Add(context.Background(), 1, api.WithAttributes(successActionlabels...))
+	}
+	for i := 0; i < errorActionMetricsTotal; i++ {
+		metrics.actionsCounterV2.Add(context.Background(), 1, api.WithAttributes(errorActionlabels...))
+	}
+
+	responseRecorder := mockMetricsRequest()
+
+	validateStatus(t, responseRecorder)
+
+	metricsMap := getMetricsMap(responseRecorder.Body.String())
+
+	validateEventErrorTotal(t, metricsMap, errorEventMetricsTotal)
+	validateActionTotalV2(t, metricsMap, successActionMetricsTotal, successStatus)
+	validateActionTotalV2(t, metricsMap, errorActionMetricsTotal, errorStatus)
+}
+
+func TestServeMetrics(t *testing.T) {
+	server := serveMetrics(mockDefaultPort)
+
+	defer func() {
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		if err := server.Shutdown(ctx); err != nil {
+			t.Errorf("failed to shutdown server: %v", err)
+		}
+	}()
+
+	time.Sleep(100 * time.Millisecond)
+
+	conn, err := net.DialTimeout("tcp", fmt.Sprintf("localhost:%d", mockDefaultPort), time.Second)
+	if err != nil {
+		t.Errorf("server is not listening on port %d: %v", mockDefaultPort, err)
+	}
+	conn.Close()
+
+	conn, err = net.DialTimeout("tcp", fmt.Sprintf("localhost:%d", mockClosedPort), time.Second)
+	if err == nil {
+		conn.Close()
+		t.Errorf("server should not be listening on port %d: %v", mockClosedPort, err)
+	}
+}
+
+func getMetrics(t *testing.T) *Metrics {
+	exporter, err := prometheus.New()
+	if err != nil {
+		t.Errorf("failed to create Prometheus exporter: %v", err)
+	}
+	provider := metric.NewMeterProvider(metric.WithReader(exporter))
+	metrics, err := registerMetricsWith(provider)
+	if err != nil {
+		t.Errorf("failed to register metrics with Prometheus provider: %v", err)
+	}
+	metrics.enabled = true
+
+	t.Cleanup(func() {
+		if provider != nil {
+			if err := provider.Shutdown(context.Background()); err != nil {
+				t.Errorf("failed to shutdown provider: %v", err)
+			}
+		}
+	})
+
+	return &metrics
+}
+
+func mockMetricsRequest() *httptest.ResponseRecorder {
+	handler := promhttp.Handler()
+	req := httptest.NewRequest("GET", metricsEndpoint, nil)
+	responseRecorder := httptest.NewRecorder()
+	handler.ServeHTTP(responseRecorder, req)
+	return responseRecorder
+}
+
+func validateStatus(t *testing.T, responseRecorder *httptest.ResponseRecorder) {
+	status := responseRecorder.Code
+	h.Equals(t, http.StatusOK, status)
+}
+
+// This method take response body got from Prometheus exporter as arg
+// Example:
+// # HELP go_goroutines Number of goroutines that currently exist.
+// # TYPE go_goroutines gauge
+// go_goroutines 6
+func getMetricsMap(body string) map[string]string {
+	metricsMap := make(map[string]string)
+	lines := strings.Split(body, "\n")
+	for _, line := range lines {
+		if len(strings.TrimSpace(line)) == 0 {
+			continue
+		}
+		if strings.HasPrefix(strings.TrimSpace(line), "# ") {
+			continue
+		}
+		parts := strings.SplitN(line, " ", 2)
+		if len(parts) != 2 {
+			continue
+		}
+		key := parts[0]
+		value := parts[1]
+		metricsMap[key] = value
+	}
+	return metricsMap
+}
+
+func validateEventErrorTotal(t *testing.T, metricsMap map[string]string, expectedTotal int) {
+	eventErrorTotalKey := fmt.Sprintf("events_error_total{event_error_where=\"%v\",otel_scope_name=\"%v\",otel_scope_version=\"\"}", mockErrorEvent, mockNth)
+	actualValue, exists := metricsMap[eventErrorTotalKey]
+	if !exists {
+		actualValue = "0"
+	}
+	h.Equals(t, strconv.Itoa(expectedTotal), actualValue)
+}
+
+func validateActionTotalV2(t *testing.T, metricsMap map[string]string, expectedTotal int, nodeStatus string) {
+	actionTotalKey := fmt.Sprintf("actions_total{node_action=\"%v\",node_status=\"%v\",otel_scope_name=\"%v\",otel_scope_version=\"\"}", mockAction, nodeStatus, mockNth)
+	actualValue, exists := metricsMap[actionTotalKey]
+	if !exists {
+		actualValue = "0"
+	}
+	h.Equals(t, strconv.Itoa(expectedTotal), actualValue)
+}