Have the same behavior as the Datadog Agent with tags

Only env should be added to host tags if set.

Author: mx-psi

exporter/datadogexporter/config.go

@@ -99,18 +99,10 @@ type TagsConfig struct {
 
 // GetTags gets the default tags extracted from the configuration
 func (t *TagsConfig) GetTags() []string {
-	tags := make([]string, 0, 4)
+	tags := make([]string, 0, len(t.Tags)+1)
 
-	vars := map[string]string{
-		"env":     t.Env,
-		"service": t.Service,
-		"version": t.Version,
-	}
-
-	for name, val := range vars {
-		if val != "" {
-			tags = append(tags, fmt.Sprintf("%s:%s", name, val))
-		}
+	if t.Env != "none" {
+		tags = append(tags, fmt.Sprintf("env:%s", t.Env))
 	}
 
 	tags = append(tags, t.Tags...)

exporter/datadogexporter/config_test.go

@@ -84,7 +84,11 @@ func TestLoadConfig(t *testing.T) {
 
 func TestTags(t *testing.T) {
 	tc := TagsConfig{
-		Env:     "customenv",
+		// environment should be picked up if it is not 'none'
+		Env: "customenv",
+
+		// these should be ignored;
+		// they are used only on trace translation
 		Service: "customservice",
 		Version: "customversion",
 		Tags:    []string{"key1:val1", "key2:val2"},
@@ -93,13 +97,14 @@ func TestTags(t *testing.T) {
 	assert.ElementsMatch(t,
 		[]string{
 			"env:customenv",
-			"service:customservice",
-			"version:customversion",
 			"key1:val1",
 			"key2:val2",
 		},
-		tc.GetTags(), // get host
+		tc.GetTags(),
 	)
+
+	tc.Env = "none"
+	assert.ElementsMatch(t, tc.GetTags(), tc.Tags)
 }
 
 // TestOverrideMetricsURL tests that the metrics URL is overridden

exporter/datadogexporter/host.go

@@ -68,7 +68,7 @@ type hostTags struct {
 // meta includes metadata about the host aliases
 type meta struct {
 	// InstanceID is the EC2 instance id the Collector is running on, if available
-	InstanceID string `json:"instance-id,omitemtpy"`
+	InstanceID string `json:"instance-id,omitempty"`
 
 	// EC2Hostname is the hostname from the EC2 metadata API
 	EC2Hostname string `json:"ec2-hostname,omitempty"`

exporter/datadogexporter/metrics_exporter.go

@@ -50,12 +50,13 @@ func (exp *metricsExporter) pushHostMetadata(metadata hostMetadata) error {
 
 	client := &http.Client{Timeout: 10 * time.Second}
 	resp, err := client.Do(req)
-	defer resp.Body.Close()
 
 	if err != nil {
 		return err
 	}
 
+	defer resp.Body.Close()
+
 	if resp.StatusCode/100 >= 4 {
 		return fmt.Errorf(
 			"'%d - %s' error when sending metadata payload to %s",