order env vars to match existing

Author: atoulme

pkg/instrumentation/sdk.go

@@ -253,26 +253,36 @@ func getContainerIndex(containerName string, pod corev1.Pod) int {
 func (i *sdkInjector) injectCommonEnvVar(otelinst v1alpha1.Instrumentation, pod corev1.Pod, index int) corev1.Pod {
 	container := &pod.Spec.Containers[index]
 
-	container.Env = appendIfNotSet(container.Env,
-		corev1.EnvVar{
+	idx := getIndexOfEnv(container.Env, constants.EnvPodIP)
+	if idx == -1 {
+		container.Env = append([]corev1.EnvVar{{
 			Name: constants.EnvPodIP,
 			ValueFrom: &corev1.EnvVarSource{
 				FieldRef: &corev1.ObjectFieldSelector{
 					FieldPath: "status.podIP",
 				},
 			},
-		},
-		corev1.EnvVar{
+		}}, container.Env...)
+	}
+
+	idx = getIndexOfEnv(container.Env, constants.EnvNodeIP)
+	if idx == -1 {
+		container.Env = append([]corev1.EnvVar{{
 			Name: constants.EnvNodeIP,
 			ValueFrom: &corev1.EnvVarSource{
 				FieldRef: &corev1.ObjectFieldSelector{
 					FieldPath: "status.hostIP",
 				},
 			},
-		},
-	)
+		}}, container.Env...)
+	}
 
-	container.Env = appendIfNotSet(container.Env, otelinst.Spec.Env...)
+	for _, env := range otelinst.Spec.Env {
+		idx := getIndexOfEnv(container.Env, env.Name)
+		if idx == -1 {
+			container.Env = append(container.Env, env)
+		}
+	}
 	return pod
 }
 
@@ -287,10 +297,13 @@ func (i *sdkInjector) injectCommonSDKConfig(ctx context.Context, otelinst v1alph
 	container := &pod.Spec.Containers[agentIndex]
 	useLabelsForResourceAttributes := otelinst.Spec.Defaults.UseLabelsForResourceAttributes
 	resourceMap := i.createResourceMap(ctx, otelinst, ns, pod, appIndex)
-	container.Env = appendIfNotSet(container.Env, corev1.EnvVar{
-		Name:  constants.EnvOTELServiceName,
-		Value: chooseServiceName(pod, useLabelsForResourceAttributes, resourceMap, appIndex),
-	})
+	idx := getIndexOfEnv(container.Env, constants.EnvOTELServiceName)
+	if idx == -1 {
+		container.Env = append(container.Env, corev1.EnvVar{
+			Name:  constants.EnvOTELServiceName,
+			Value: chooseServiceName(pod, useLabelsForResourceAttributes, resourceMap, appIndex),
+		})
+	}
 	configureExporter(otelinst.Spec.Exporter, &pod, container)
 
 	// Always retrieve the pod name from the Downward API. Ensure that the OTEL_RESOURCE_ATTRIBUTES_POD_NAME env exists.
@@ -319,7 +332,7 @@ func (i *sdkInjector) injectCommonSDKConfig(ctx context.Context, otelinst v1alph
 		}
 	}
 
-	idx := getIndexOfEnv(container.Env, constants.EnvOTELResourceAttrs)
+	idx = getIndexOfEnv(container.Env, constants.EnvOTELResourceAttrs)
 	if idx == -1 || !strings.Contains(container.Env[idx].Value, string(semconv.ServiceVersionKey)) {
 		vsn := chooseServiceVersion(pod, useLabelsForResourceAttributes, appIndex)
 		if vsn != "" {