Add sdk-only support for opentelemetry-autoinstrumentation

Signed-off-by: Israel Blancas <iblancasa@gmail.com>

Author: iblancasa

otel-integration/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## OpenTelemetry-Integration
 
+### v0.0.326 / 2026-07-13
+
+- [Chore] Bump OpenTelemetry Operator chart dependency to 0.119.0
+- [Feat] Add SDK-only injection support for applications with manual instrumentation
+
 ### v0.0.325 / 2026-07-07
 
 - [Chore] Bump chart dependency to opentelemetry-collector 0.134.4

otel-integration/k8s-helm/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v2
 name: otel-integration
 description: OpenTelemetry Integration
-version: 0.0.325
+version: 0.0.326
 keywords:
   - OpenTelemetry Collector
   - OpenTelemetry Agent
@@ -16,7 +16,7 @@ dependencies:
     condition: opentelemetry-agent.enabled
   - name: opentelemetry-operator
     alias: opentelemetry-autoinstrumentation
-    version: "0.115.1"
+    version: "0.119.0"
     repository: https://open-telemetry.github.io/opentelemetry-helm-charts
     condition: opentelemetry-autoinstrumentation.enabled
   - name: opentelemetry-collector

otel-integration/k8s-helm/README.md

@@ -205,10 +205,30 @@ Supported annotations:
 instrumentation.opentelemetry.io/inject-java: "true"
 instrumentation.opentelemetry.io/inject-python: "true"
 instrumentation.opentelemetry.io/inject-dotnet: "true"
+instrumentation.opentelemetry.io/inject-sdk: "true"
 ```
 
 Java and .NET use OTLP/gRPC to `http://$(OTEL_NODE_IP):4317`. Python uses OTLP HTTP/protobuf to `http://$(OTEL_NODE_IP):4318`.
 
+#### SDK-only Injection
+
+The `inject-sdk` annotation enables SDK-only injection mode for applications that are already manually instrumented or cannot be auto-instrumented with language-specific agents. This mode injects only OpenTelemetry SDK environment variables without adding init containers or modifying the application binary.
+
+Use this mode when:
+- Your application is already instrumented with OpenTelemetry SDK
+- You want centralized configuration of SDK behavior via Kubernetes annotations
+- Language-specific auto-instrumentation is not available or compatible
+
+Example pod annotation:
+
+```yaml
+metadata:
+  annotations:
+    instrumentation.opentelemetry.io/inject-sdk: "true"
+```
+
+The injected environment variables will configure the SDK to send telemetry to the `opentelemetry-agent` DaemonSet on the same node using `http://$(OTEL_NODE_IP):4317`.
+
 > [!IMPORTANT]
 >
 > Do not enable `opentelemetry-autoinstrumentation` in a cluster that already has another OpenTelemetry Operator webhook installed, unless the webhook names and selectors are configured to avoid collisions.

otel-integration/k8s-helm/e2e-test/instrumentation_webhook_test.go

@@ -494,3 +494,110 @@ func eventually(timeout, interval time.Duration, check func() (bool, error)) err
 	}
 	return fmt.Errorf("condition not met within %s", timeout)
 }
+
+func TestE2E_SDKInjection(t *testing.T) {
+	kubeconfigPath := testKubeConfig
+	if kubeConfigFromEnv := os.Getenv(kubeConfigEnvVar); kubeConfigFromEnv != "" {
+		kubeconfigPath = kubeConfigFromEnv
+	}
+
+	k8sClient, err := xk8stest.NewK8sClient(kubeconfigPath)
+	require.NoError(t, err)
+
+	require.NoError(t, waitForInstrumentationWebhookManager(k8sClient))
+
+	ns := fmt.Sprintf("sdk-injection-e2e-%s", uuid.NewString()[:8])
+	nsObj := &unstructured.Unstructured{Object: map[string]any{
+		"apiVersion": "v1",
+		"kind":       "Namespace",
+		"metadata": map[string]any{
+			"name": ns,
+		},
+	}}
+	_, err = k8sClient.DynamicClient.Resource(corev1.SchemeGroupVersion.WithResource("namespaces")).Create(context.Background(), nsObj, metav1.CreateOptions{})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		_ = xk8stest.DeleteObject(k8sClient, nsObj)
+	})
+
+	tracesConsumer := new(consumertest.TracesSink)
+	shutdownSink := StartUpSinks(t, ReceiverSinks{
+		Traces: &TraceSinkConfig{
+			Consumer: tracesConsumer,
+			Ports: &ReceiverPorts{
+				Grpc: 4321,
+			},
+		},
+	})
+	defer shutdownSink()
+
+	tests := []struct {
+		name           string
+		image          string
+		port           int
+		path           string
+		command        []string
+		expectedEnvs   []string
+		noExpectedInit bool
+	}{
+		{
+			name:  "sdk-only-python",
+			image: "ghcr.io/open-telemetry/opentelemetry-operator/e2e-test-app-python:main",
+			port:  8080,
+			path:  "/",
+			expectedEnvs: []string{
+				"OTEL_EXPORTER_OTLP_ENDPOINT",
+				"OTEL_NODE_IP",
+				"OTEL_TRACES_SAMPLER",
+				"OTEL_LOGS_EXPORTER",
+			},
+			noExpectedInit: true,
+		},
+		{
+			name:  "sdk-only-java",
+			image: "ghcr.io/open-telemetry/opentelemetry-operator/e2e-test-app-java:main",
+			port:  8080,
+			path:  "/",
+			expectedEnvs: []string{
+				"OTEL_EXPORTER_OTLP_ENDPOINT",
+				"OTEL_NODE_IP",
+				"OTEL_TRACES_SAMPLER",
+				"OTEL_LOGS_EXPORTER",
+			},
+			noExpectedInit: true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			deployment := instrumentationWebhookDeployment(tc.name, ns, "", tc.image, tc.port, tc.path, tc.command, nil, "")
+			created, err := k8sClient.DynamicClient.Resource(appsV1Deployments()).Namespace(ns).Create(context.Background(), deployment, metav1.CreateOptions{})
+			require.NoError(t, err)
+			t.Cleanup(func() {
+				_ = xk8stest.DeleteObject(k8sClient, created)
+			})
+
+			baselinePod := waitForDeploymentReadyPod(t, k8sClient, ns, created.GetName(), "")
+			curlPod(t, k8sClient, ns, baselinePod.GetName(), tc.port, tc.path)
+			requireNoTraceForPod(t, tracesConsumer, baselinePod.GetName(), 15*time.Second)
+
+			err = injectDeploymentInstrumentation(k8sClient, ns, created.GetName(), "instrumentation.opentelemetry.io/inject-sdk")
+			require.NoError(t, err)
+
+			instrumentedPod := waitForDeploymentReadyPod(t, k8sClient, ns, created.GetName(), baselinePod.GetName())
+
+			if tc.noExpectedInit {
+				initContainers, found, _ := unstructured.NestedSlice(instrumentedPod.Object, "spec", "initContainers")
+				if found && len(initContainers) > 0 {
+					t.Errorf("SDK-only injection should not add init containers, but found %d init containers", len(initContainers))
+				}
+			}
+
+			for _, envName := range tc.expectedEnvs {
+				require.Truef(t, containerHasEnv(instrumentedPod, "app", envName), "expected env %q on container 'app' in pod %s", envName, tc.name)
+			}
+
+			t.Logf("SDK-only injection verified for %s - environment variables injected without init containers", tc.name)
+		})
+	}
+}

otel-integration/k8s-helm/e2e-test/run-all.sh

@@ -91,6 +91,7 @@ TestE2E_DeltaToCumulativePreset|linux|component=agent-collector||./values.yaml .
 TestE2E_SpanMetricsConnector|linux|component=agent-collector||./values.yaml ./e2e-test/testdata/values-e2e-span-metrics.yaml
 TestE2E_SpanSanitization|linux|component=agent-collector||./values.yaml ./e2e-test/testdata/values-e2e-test.yaml
 TestE2E_InstrumentationWebhookNoCRDs|linux|component=agent-collector||./values.yaml ./e2e-test/testdata/values-e2e-test.yaml ./e2e-test/testdata/values-e2e-instrumentation-webhook.yaml
+TestE2E_SDKInjection|linux|component=agent-collector||./values.yaml ./e2e-test/testdata/values-e2e-test.yaml ./e2e-test/testdata/values-e2e-sdk-injection.yaml
 EOF
 }
 

otel-integration/k8s-helm/e2e-test/testdata/values-e2e-sdk-injection.yaml

@@ -0,0 +1,11 @@
+opentelemetry-autoinstrumentation:
+  enabled: true
+
+opentelemetry-agent:
+  config:
+    service:
+      pipelines:
+        traces:
+          exporters:
+            - otlp/traces
+            - debug

otel-integration/k8s-helm/values.yaml

@@ -5,7 +5,7 @@ global:
   defaultSubsystemName: "integration"
   logLevel: "info"
   collectionInterval: "30s"
-  version: "0.0.325"
+  version: "0.0.326"
   deploymentEnvironmentName: ""
 
   extensions:
@@ -84,6 +84,14 @@ opentelemetry-autoinstrumentation:
                 value: http://$(OTEL_NODE_IP):4317
               - name: OTEL_EXPORTER_OTLP_PROTOCOL
                 value: grpc
+          # SDK-only injection mode for applications that already have instrumentation
+          # or cannot be auto-instrumented.
+          sdk:
+            env:
+              - name: OTEL_EXPORTER_OTLP_ENDPOINT
+                value: http://$(OTEL_NODE_IP):4317
+              - name: OTEL_EXPORTER_OTLP_PROTOCOL
+                value: grpc
   # Webhook manager runs only on Linux nodes.
   nodeSelector:
     kubernetes.io/os: linux