Merge pull request #30 from DataDog/darcy.rayner/enhanced-metrics-by-…

…default

Always send enhanced metrics through logs

ddlambda.go

@@ -129,7 +129,7 @@ func MetricWithTimestamp(metric string, value float64, timestamp time.Time, tags
 		logger.Error(fmt.Errorf("couldn't get metrics listener from current context"))
 		return
 	}
-	listener.AddDistributionMetric(metric, value, timestamp, tags...)
+	listener.AddDistributionMetric(metric, value, timestamp, false, tags...)
 }
 
 // InvokeDryRun is a utility to easily run your lambda for testing

internal/logger/log.go

@@ -3,7 +3,9 @@ package logger
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"log"
+	"os"
 )
 
 // LogLevel represents the level of logging that should be performed
@@ -17,14 +19,21 @@ const (
 )
 
 var (
-	logLevel = LevelError
+	logLevel           = LevelError
+	output   io.Writer = os.Stdout
 )
 
 // SetLogLevel set the level of logging for the ddlambda
 func SetLogLevel(ll LogLevel) {
 	logLevel = ll
 }
 
+// SetOutput changes the writer for the logger
+func SetOutput(w io.Writer) {
+	log.SetOutput(w)
+	output = w
+}
+
 // Error logs a structured error message to stdout
 func Error(err error) {
 
@@ -60,3 +69,8 @@ func Debug(message string) {
 
 	log.Println(string(result))
 }
+
+// Raw prints a raw message to the logs.
+func Raw(message string) {
+	fmt.Fprintln(output, message)
+}

internal/metrics/listener.go

@@ -99,12 +99,12 @@ func (l *Listener) HandlerFinished(ctx context.Context) {
 }
 
 // AddDistributionMetric sends a distribution metric
-func (l *Listener) AddDistributionMetric(metric string, value float64, timestamp time.Time, tags ...string) {
+func (l *Listener) AddDistributionMetric(metric string, value float64, timestamp time.Time, forceLogForwarder bool, tags ...string) {
 
 	// We add our own runtime tag to the metric for version tracking
 	tags = append(tags, getRuntimeTag())
 
-	if l.config.ShouldUseLogForwarder {
+	if l.config.ShouldUseLogForwarder || forceLogForwarder {
 		logger.Debug("sending metric via log forwarder")
 		unixTime := timestamp.Unix()
 		lm := logMetric{
@@ -119,7 +119,7 @@ func (l *Listener) AddDistributionMetric(metric string, value float64, timestamp
 			return
 		}
 		payload := string(result)
-		println(payload)
+		logger.Raw(payload)
 		return
 	}
 	m := Distribution{
@@ -140,7 +140,7 @@ func getRuntimeTag() string {
 func (l *Listener) submitEnhancedMetrics(metricName string, ctx context.Context) {
 	if l.config.EnhancedMetrics {
 		tags := getEnhancedMetricsTags(ctx)
-		l.AddDistributionMetric(fmt.Sprintf("aws.lambda.enhanced.%s", metricName), 1, time.Now(), tags...)
+		l.AddDistributionMetric(fmt.Sprintf("aws.lambda.enhanced.%s", metricName), 1, time.Now(), true, tags...)
 	}
 }
 

internal/metrics/listener_test.go

@@ -9,17 +9,30 @@
 package metrics
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
-	"github.com/aws/aws-lambda-go/lambdacontext"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"strings"
 	"testing"
 	"time"
 
+	"github.com/DataDog/datadog-lambda-go/internal/logger"
+	"github.com/aws/aws-lambda-go/lambdacontext"
+
 	"github.com/stretchr/testify/assert"
 )
 
+func captureOutput(f func()) string {
+	var buf bytes.Buffer
+	logger.SetOutput(&buf)
+	f()
+	logger.SetOutput(os.Stderr)
+	return buf.String()
+}
+
 func TestHandlerAddsItselfToContext(t *testing.T) {
 	listener := MakeListener(Config{})
 	ctx := listener.HandlerStarted(context.Background(), json.RawMessage{})
@@ -47,7 +60,7 @@ func TestAddDistributionMetricWithAPI(t *testing.T) {
 
 	listener := MakeListener(Config{APIKey: "12345", Site: server.URL})
 	ctx := listener.HandlerStarted(context.Background(), json.RawMessage{})
-	listener.AddDistributionMetric("the-metric", 2, time.Now(), "tag:a", "tag:b")
+	listener.AddDistributionMetric("the-metric", 2, time.Now(), false, "tag:a", "tag:b")
 	listener.HandlerFinished(ctx)
 	assert.True(t, called)
 }
@@ -62,7 +75,21 @@ func TestAddDistributionMetricWithLogForwarder(t *testing.T) {
 
 	listener := MakeListener(Config{APIKey: "12345", Site: server.URL, ShouldUseLogForwarder: true})
 	ctx := listener.HandlerStarted(context.Background(), json.RawMessage{})
-	listener.AddDistributionMetric("the-metric", 2, time.Now(), "tag:a", "tag:b")
+	listener.AddDistributionMetric("the-metric", 2, time.Now(), false, "tag:a", "tag:b")
+	listener.HandlerFinished(ctx)
+	assert.False(t, called)
+}
+func TestAddDistributionMetricWithForceLogForwarder(t *testing.T) {
+	called := false
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		called = true
+		w.WriteHeader(http.StatusCreated)
+	}))
+	defer server.Close()
+
+	listener := MakeListener(Config{APIKey: "12345", Site: server.URL, ShouldUseLogForwarder: false})
+	ctx := listener.HandlerStarted(context.Background(), json.RawMessage{})
+	listener.AddDistributionMetric("the-metric", 2, time.Now(), true, "tag:a", "tag:b")
 	listener.HandlerFinished(ctx)
 	assert.False(t, called)
 }
@@ -96,17 +123,21 @@ func TestSubmitEnhancedMetrics(t *testing.T) {
 	defer server.Close()
 	ml := MakeListener(
 		Config{
-			APIKey:                "abc-123",
-			Site:                  server.URL,
-			EnhancedMetrics:       true,
+			APIKey:          "abc-123",
+			Site:            server.URL,
+			EnhancedMetrics: true,
 		},
 	)
 	ctx := context.WithValue(context.Background(), "cold_start", false)
 
-	ctx = ml.HandlerStarted(ctx, json.RawMessage{})
-	ml.HandlerFinished(ctx)
+	output := captureOutput(func() {
+		ctx = ml.HandlerStarted(ctx, json.RawMessage{})
+		ml.HandlerFinished(ctx)
+	})
 
-	assert.True(t, called)
+	assert.False(t, called)
+	expected := "{\"m\":\"aws.lambda.enhanced.invocations\",\"v\":1,"
+	assert.True(t, strings.Contains(output, expected))
 }
 
 func TestDoNotSubmitEnhancedMetrics(t *testing.T) {
@@ -119,17 +150,21 @@ func TestDoNotSubmitEnhancedMetrics(t *testing.T) {
 
 	ml := MakeListener(
 		Config{
-			APIKey:                "abc-123",
-			Site:                  server.URL,
-			EnhancedMetrics:       false,
+			APIKey:          "abc-123",
+			Site:            server.URL,
+			EnhancedMetrics: false,
 		},
 	)
 	ctx := context.WithValue(context.Background(), "cold_start", true)
 
-	ctx = ml.HandlerStarted(ctx, json.RawMessage{})
-	ml.HandlerFinished(ctx)
+	output := captureOutput(func() {
+		ctx = ml.HandlerStarted(ctx, json.RawMessage{})
+		ml.HandlerFinished(ctx)
+	})
 
 	assert.False(t, called)
+	expected := "{\"m\":\"aws.lambda.enhanced.invocations\",\"v\":1,"
+	assert.False(t, strings.Contains(output, expected))
 }
 
 func TestSubmitEnhancedMetricsOnlyErrors(t *testing.T) {
@@ -142,17 +177,22 @@ func TestSubmitEnhancedMetricsOnlyErrors(t *testing.T) {
 
 	ml := MakeListener(
 		Config{
-			APIKey:                "abc-123",
-			Site:                  server.URL,
-			EnhancedMetrics:       false,
+			APIKey:          "abc-123",
+			Site:            server.URL,
+			EnhancedMetrics: false,
 		},
 	)
+
 	ctx := context.WithValue(context.Background(), "cold_start", true)
 
-	ctx = ml.HandlerStarted(ctx, json.RawMessage{})
-	ml.config.EnhancedMetrics = true
-	ctx = context.WithValue(ctx, "error", true)
-	ml.HandlerFinished(ctx)
+	output := captureOutput(func() {
+		ctx = ml.HandlerStarted(ctx, json.RawMessage{})
+		ml.config.EnhancedMetrics = true
+		ctx = context.WithValue(ctx, "error", true)
+		ml.HandlerFinished(ctx)
+	})
 
-	assert.True(t, called)
-}
+	assert.False(t, called)
+	expected := "{\"m\":\"aws.lambda.enhanced.errors\",\"v\":1,"
+	assert.True(t, strings.Contains(output, expected))
+}