Remove the mapping of app.kubernetes.io/instance to service.instance.id, because multiple containers

  should never share the same `service.instance.id`

Author: zeitlinger

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 <!-- next version -->
 
+### 🧰 Bug fixes 🧰
+
+- Remove the mapping of `app.kubernetes.io/instance` to `service.instance.id`, because multiple containers 
+  should never share the same `service.instance.id` (#3495)
+
 ## 0.113.0
 
 ### 💡 Enhancements 💡
@@ -220,8 +225,6 @@
     - `app.kubernetes.io/name` becomes `service.name`
     - `app.kubernetes.io/version` becomes `service.version`
     - `app.kubernetes.io/part-of` becomes `service.namespace`
-    - `app.kubernetes.io/instance` becomes `service.instance.id`
-  
 
 ### 🧰 Bug fixes 🧰
 

README.md

@@ -725,14 +725,16 @@ EOF
 
 ### Configure resource attributes with annotations
 
-This example shows a pod configuration with OpenTelemetry annotations using the `resource.opentelemetry.io/` prefix. These annotations can be used to add resource attributes to data produced by OpenTelemetry instrumentation.
+This example shows a pod configuration with OpenTelemetry annotations using the `resource.opentelemetry.io/` prefix. 
+These annotations can be used to add resource attributes to data produced by OpenTelemetry instrumentation.
 
 ```yaml
 apiVersion: v1
 kind: Pod
 metadata:
   name: example-pod
   annotations:
+    # this is just an example, you can create any resource attributes you need
     resource.opentelemetry.io/service.name: "my-service"
     resource.opentelemetry.io/service.version: "1.0.0"
     resource.opentelemetry.io/environment: "production"
@@ -750,7 +752,6 @@ The following labels are supported:
 - `app.kubernetes.io/name` becomes `service.name`
 - `app.kubernetes.io/version` becomes `service.version`
 - `app.kubernetes.io/part-of` becomes `service.namespace`
-- `app.kubernetes.io/instance` becomes `service.instance.id`
 
 ```yaml
 apiVersion: v1
@@ -761,7 +762,6 @@ metadata:
     app.kubernetes.io/name: "my-service"
     app.kubernetes.io/version: "1.0.0"
     app.kubernetes.io/part-of: "shop"
-    app.kubernetes.io/instance: "my-service-123"
 spec:
   containers:
   - name: main-container

docs/api.md

@@ -1389,8 +1389,7 @@ Defaults defines default values for the instrumentation.
           UseLabelsForResourceAttributes defines whether to use common labels for resource attributes:
   - `app.kubernetes.io/name` becomes `service.name`
   - `app.kubernetes.io/version` becomes `service.version`
-  - `app.kubernetes.io/part-of` becomes `service.namespace`
-  - `app.kubernetes.io/instance` becomes `service.instance.id`<br/>
+  - `app.kubernetes.io/part-of` becomes `service.namespace`<br/>
         </td>
         <td>false</td>
       </tr></tbody>
@@ -54000,4 +53999,4 @@ Deployment, Daemonset, StatefulSet.<br/>
         </td>
         <td>false</td>
       </tr></tbody>
-</table>
+</table>

pkg/constants/env.go

@@ -35,10 +35,9 @@ const (
 	AnnotationDefaultAutoInstrumentationApacheHttpd = InstrumentationPrefix + "default-auto-instrumentation-apache-httpd-image"
 	AnnotationDefaultAutoInstrumentationNginx       = InstrumentationPrefix + "default-auto-instrumentation-nginx-image"
 
-	LabelAppName     = "app.kubernetes.io/name"
-	LabelAppInstance = "app.kubernetes.io/instance"
-	LabelAppVersion  = "app.kubernetes.io/version"
-	LabelAppPartOf   = "app.kubernetes.io/part-of"
+	LabelAppName    = "app.kubernetes.io/name"
+	LabelAppVersion = "app.kubernetes.io/version"
+	LabelAppPartOf  = "app.kubernetes.io/part-of"
 
 	LabelTargetAllocator              = "opentelemetry.io/target-allocator"
 	ResourceAttributeAnnotationPrefix = "resource.opentelemetry.io/"

pkg/instrumentation/sdk.go

@@ -469,11 +469,16 @@ func chooseServiceVersion(pod corev1.Pod, useLabelsForResourceAttributes bool, i
 
 // chooseServiceInstanceId returns the service.instance.id to be used in the instrumentation.
 // The precedence is as follows:
-//  1. annotation with key "service.instance.id" or "app.kubernetes.io/instance"
+//  1. annotation with key "service.instance.id"
 //  2. namespace name + pod name + container name
 //     (as defined by https://opentelemetry.io/docs/specs/semconv/resource/#service-experimental)
 func createServiceInstanceId(pod corev1.Pod, useLabelsForResourceAttributes bool, namespaceName, podName, containerName string) string {
-	serviceInstanceId := chooseLabelOrAnnotation(pod, useLabelsForResourceAttributes, semconv.ServiceInstanceIDKey, constants.LabelAppInstance)
+	// Do not use labels for service instance id,
+	// because multiple containers in the same pod would get the same service instance id,
+	// which violates the uniqueness requirement of service instance id -
+	// see https://opentelemetry.io/docs/specs/semconv/resource/#service-experimental.
+	// We still allow the user to set the service instance id via annotation, because this is explicitly set by the user.
+	serviceInstanceId := chooseLabelOrAnnotation(pod, false, semconv.ServiceInstanceIDKey, "")
 	if serviceInstanceId != "" {
 		return serviceInstanceId
 	}

pkg/instrumentation/sdk_test.go

@@ -156,10 +156,9 @@ func TestSDKInjection(t *testing.T) {
 						},
 					},
 					Labels: map[string]string{
-						"app.kubernetes.io/name":     "app-name",
-						"app.kubernetes.io/instance": "app-id",
-						"app.kubernetes.io/version":  "v1",
-						"app.kubernetes.io/part-of":  "shop",
+						"app.kubernetes.io/name":    "app-name",
+						"app.kubernetes.io/version": "v1",
+						"app.kubernetes.io/part-of": "shop",
 					},
 					Annotations: map[string]string{
 						"resource.opentelemetry.io/foo": "bar",
@@ -180,10 +179,9 @@ func TestSDKInjection(t *testing.T) {
 					Name:      "app",
 					UID:       "pod-uid",
 					Labels: map[string]string{
-						"app.kubernetes.io/name":     "app-name",
-						"app.kubernetes.io/instance": "app-id",
-						"app.kubernetes.io/version":  "v1",
-						"app.kubernetes.io/part-of":  "shop",
+						"app.kubernetes.io/name":    "app-name",
+						"app.kubernetes.io/version": "v1",
+						"app.kubernetes.io/part-of": "shop",
 					},
 					Annotations: map[string]string{
 						"resource.opentelemetry.io/foo": "bar",
@@ -396,10 +394,9 @@ func TestSDKInjection(t *testing.T) {
 						},
 					},
 					Labels: map[string]string{
-						"app.kubernetes.io/name":     "app-name",
-						"app.kubernetes.io/instance": "app-id",
-						"app.kubernetes.io/version":  "v1",
-						"app.kubernetes.io/part-of":  "shop",
+						"app.kubernetes.io/name":    "app-name",
+						"app.kubernetes.io/version": "v1",
+						"app.kubernetes.io/part-of": "shop",
 					},
 					Annotations: map[string]string{
 						"resource.opentelemetry.io/foo": "bar",
@@ -420,10 +417,9 @@ func TestSDKInjection(t *testing.T) {
 					Name:      "app",
 					UID:       "pod-uid",
 					Labels: map[string]string{
-						"app.kubernetes.io/name":     "app-name",
-						"app.kubernetes.io/instance": "app-id",
-						"app.kubernetes.io/version":  "v1",
-						"app.kubernetes.io/part-of":  "shop",
+						"app.kubernetes.io/name":    "app-name",
+						"app.kubernetes.io/version": "v1",
+						"app.kubernetes.io/part-of": "shop",
 					},
 					Annotations: map[string]string{
 						"resource.opentelemetry.io/foo": "bar",
@@ -481,7 +477,7 @@ func TestSDKInjection(t *testing.T) {
 								},
 								{
 									Name:  "OTEL_RESOURCE_ATTRIBUTES",
-									Value: "foo=bar,k8s.container.name=application-name,k8s.deployment.name=my-deployment,k8s.deployment.uid=depuid,k8s.namespace.name=project1,k8s.node.name=$(OTEL_RESOURCE_ATTRIBUTES_NODE_NAME),k8s.pod.name=$(OTEL_RESOURCE_ATTRIBUTES_POD_NAME),k8s.pod.uid=pod-uid,k8s.replicaset.name=my-replicaset,k8s.replicaset.uid=rsuid,service.instance.id=app-id,service.namespace=shop,service.version=v1",
+									Value: "foo=bar,k8s.container.name=application-name,k8s.deployment.name=my-deployment,k8s.deployment.uid=depuid,k8s.namespace.name=project1,k8s.node.name=$(OTEL_RESOURCE_ATTRIBUTES_NODE_NAME),k8s.pod.name=$(OTEL_RESOURCE_ATTRIBUTES_POD_NAME),k8s.pod.uid=pod-uid,k8s.replicaset.name=my-replicaset,k8s.replicaset.uid=rsuid,service.instance.id=project1.$(OTEL_RESOURCE_ATTRIBUTES_POD_NAME).application-name,service.namespace=shop,service.version=v1",
 								},
 							},
 						},
@@ -516,10 +512,9 @@ func TestSDKInjection(t *testing.T) {
 					Namespace: "project1",
 					Name:      "app",
 					Labels: map[string]string{
-						"app.kubernetes.io/name":     "not-used",
-						"app.kubernetes.io/instance": "not-used",
-						"app.kubernetes.io/version":  "not-used",
-						"app.kubernetes.io/part-of":  "not-used",
+						"app.kubernetes.io/name":    "not-used",
+						"app.kubernetes.io/version": "not-used",
+						"app.kubernetes.io/part-of": "not-used",
 					},
 				},
 				Spec: corev1.PodSpec{
@@ -557,10 +552,9 @@ func TestSDKInjection(t *testing.T) {
 					Namespace: "project1",
 					Name:      "app",
 					Labels: map[string]string{
-						"app.kubernetes.io/name":     "not-used",
-						"app.kubernetes.io/instance": "not-used",
-						"app.kubernetes.io/version":  "not-used",
-						"app.kubernetes.io/part-of":  "not-used",
+						"app.kubernetes.io/name":    "not-used",
+						"app.kubernetes.io/version": "not-used",
+						"app.kubernetes.io/part-of": "not-used",
 					},
 				},
 				Spec: corev1.PodSpec{