adding in version (#43)

* adding in version

* adding in version for test

* adding in version to another test

Author: meghna-dd

internal/metrics/listener.go

@@ -22,6 +22,8 @@ import (
 	"github.com/DataDog/datadog-lambda-go/internal/logger"
 )
 
+const datadogLambdaVersion = "v0.7.0"
+
 type (
 	// Listener implements wrapper.HandlerListener, injecting metrics into the context
 	Listener struct {
@@ -162,8 +164,9 @@ func getEnhancedMetricsTags(ctx context.Context) []string {
 		memorySize := fmt.Sprintf("memorysize:%d", lambdacontext.MemoryLimitInMB)
 		coldStart := fmt.Sprintf("cold_start:%t", isColdStart.(bool))
 		resource := fmt.Sprintf("resource:%s", lambdacontext.FunctionName)
+		datadogLambda := fmt.Sprintf("datadog_lambda:%s", datadogLambdaVersion)
 
-		tags := []string{functionName, region, accountId, memorySize, coldStart}
+		tags := []string{functionName, region, accountId, memorySize, coldStart, datadogLambda}
 
 		// Check if our slice contains an alias or version
 		if len(splitArn) > 7 {

internal/metrics/listener_test.go

@@ -104,7 +104,7 @@ func TestGetEnhancedMetricsTags(t *testing.T) {
 	}
 	tags := getEnhancedMetricsTags(lambdacontext.NewContext(ctx, lc))
 
-	assert.ElementsMatch(t, tags, []string{"functionname:go-lambda-test", "region:us-east-1", "memorysize:256", "cold_start:false", "account_id:123497558138", "resource:go-lambda-test:Latest"})
+	assert.ElementsMatch(t, tags, []string{"functionname:go-lambda-test", "region:us-east-1", "memorysize:256", "cold_start:false", "account_id:123497558138", "resource:go-lambda-test:Latest", "datadog_lambda:" + datadogLambdaVersion})
 }
 
 func TestGetEnhancedMetricsTagsWithAlias(t *testing.T) {
@@ -118,7 +118,7 @@ func TestGetEnhancedMetricsTagsWithAlias(t *testing.T) {
 	}
 
 	tags := getEnhancedMetricsTags((lambdacontext.NewContext(ctx, lc)))
-	assert.ElementsMatch(t, tags, []string{"functionname:go-lambda-test", "region:us-east-1", "memorysize:256", "cold_start:false", "account_id:123497558138", "resource:go-lambda-test:my-alias", "executedversion:1"})
+	assert.ElementsMatch(t, tags, []string{"functionname:go-lambda-test", "region:us-east-1", "memorysize:256", "cold_start:false", "account_id:123497558138", "resource:go-lambda-test:my-alias", "executedversion:1", "datadog_lambda:" + datadogLambdaVersion})
 }
 
 func TestGetEnhancedMetricsTagsNoLambdaContext(t *testing.T) {