Properly handle go runtime versions containing a comma.

internal/metrics/listener.go

@@ -61,6 +61,12 @@ type (
 	}
 )
 
+var (
+	// runtimeTag is the metrics tag representing the go runtime version.  Use
+	// this rather than calling getRuntimeTag directly.
+	runtimeTag = getRuntimeTag(runtime.Version())
+)
+
 // MakeListener initializes a new metrics lambda listener
 func MakeListener(config Config, extensionManager *extension.ExtensionManager) Listener {
 
@@ -173,7 +179,7 @@ func (l *Listener) HandlerFinished(ctx context.Context, err error) {
 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())
+	tags = append(tags, runtimeTag)
 
 	if l.isAgentRunning {
 		err := l.statsdClient.Distribution(metric, value, tags, 1)
@@ -217,8 +223,12 @@ func (l *Listener) AddDistributionMetric(metric string, value float64, timestamp
 	l.processor.AddMetric(&m)
 }
 
-func getRuntimeTag() string {
-	v := runtime.Version()
+// getRuntimeTag returns the runtime tag to be used when creating distribution
+// metrics.  It should not be called directly, instead use the global
+// runtimeTag var.
+func getRuntimeTag(v string) string {
+	v = strings.ReplaceAll(v, " ", "-")
+	v = strings.ReplaceAll(v, ",", "-")
 	return fmt.Sprintf("dd_lambda_layer:datadog-%s", v)
 }
 

internal/metrics/listener_test.go

@@ -110,9 +110,9 @@ func TestAddDistributionMetricWithFIPSMode(t *testing.T) {
 
 	// Create a listener with FIPS mode enabled
 	listener := MakeListener(Config{
-		APIKey:    "12345",
-		Site:      server.URL,
-		FIPSMode:  true,
+		APIKey:   "12345",
+		Site:     server.URL,
+		FIPSMode: true,
 	}, &extension.ExtensionManager{})
 
 	// Verify the API client wasn't created
@@ -205,6 +205,7 @@ func TestSubmitEnhancedMetrics(t *testing.T) {
 	assert.False(t, called)
 	expected := "{\"m\":\"aws.lambda.enhanced.invocations\",\"v\":1,"
 	assert.True(t, strings.Contains(output, expected))
+	assert.True(t, strings.Contains(output, "dd_lambda_layer:datadog-go1."))
 }
 
 func TestDoNotSubmitEnhancedMetrics(t *testing.T) {
@@ -290,3 +291,23 @@ func TestListenerHandlerFinishedFlushes(t *testing.T) {
 		})
 	}
 }
+
+func TestGetRuntimeTag(t *testing.T) {
+	testcases := []struct {
+		runtimeVersion string
+		expect         string
+	}{
+		{"", "dd_lambda_layer:datadog-"},
+		{"go1.25.1", "dd_lambda_layer:datadog-go1.25.1"},
+		// runtime.Version() will include any values from the GOEXPERIMENT env var
+		{"go1.25.1 X:jsonv2", "dd_lambda_layer:datadog-go1.25.1-X:jsonv2"},
+		{"go1.25.1 X:fieldtrace,jsonv2", "dd_lambda_layer:datadog-go1.25.1-X:fieldtrace-jsonv2"},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.runtimeVersion, func(t *testing.T) {
+			actual := getRuntimeTag(tc.runtimeVersion)
+			assert.Equal(t, actual, tc.expect)
+		})
+	}
+}