Choose target container injection with annotation

README.md

@@ -324,4 +324,4 @@ Thanks to all the people who already contributed!
 [godoc-img]: https://godoc.org/github.com/open-telemetry/opentelemetry-operator?status.svg
 [godoc]: https://godoc.org/github.com/open-telemetry/opentelemetry-operator/pkg/apis/opentelemetry/v1alpha1#OpenTelemetryCollector
 [contributors]: https://github.com/open-telemetry/opentelemetry-operator/graphs/contributors
-[contributors-img]: https://contributors-img.web.app/image?repo=open-telemetry/opentelemetry-operator
+[contributors-img]: https://contributors-img.web.app/image?repo=open-telemetry/opentelemetry-operator

config/manager/kustomization.yaml

@@ -1,2 +1,2 @@
 resources:
-  - manager.yaml
+  - manager.yaml

kuttl-test.yaml

@@ -11,4 +11,4 @@ commands:
   - command: sleep 5s
 testDirs:
   - ./tests/e2e/
-timeout: 150
+timeout: 150

pkg/instrumentation/annotation.go

@@ -23,9 +23,10 @@ import (
 const (
 	// annotationInjectJava indicates whether java auto-instrumentation should be injected or not.
 	// Possible values are "true", "false" or "<Instrumentation>" name.
-	annotationInjectJava   = "instrumentation.opentelemetry.io/inject-java"
-	annotationInjectNodeJS = "instrumentation.opentelemetry.io/inject-nodejs"
-	annotationInjectPython = "instrumentation.opentelemetry.io/inject-python"
+	annotationInjectJava          = "instrumentation.opentelemetry.io/inject-java"
+	annotationInjectNodeJS        = "instrumentation.opentelemetry.io/inject-nodejs"
+	annotationInjectPython        = "instrumentation.opentelemetry.io/inject-python"
+	annotationInjectContainerName = "instrumentation.opentelemetry.io/container-names"
 )
 
 // annotationValue returns the effective annotationInjectJava value, based on the annotations from the pod and namespace.

pkg/instrumentation/helper.go

@@ -0,0 +1,27 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package instrumentation
+
+import corev1 "k8s.io/api/core/v1"
+
+// Calculate if we already inject InitContainers.
+func IsInitContainerMissing(pod corev1.Pod) bool {
+	for _, initContainer := range pod.Spec.InitContainers {
+		if initContainer.Name == initContainerName {
+			return false
+		}
+	}
+	return true
+}

pkg/instrumentation/helper_test.go

@@ -0,0 +1,74 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package instrumentation
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	corev1 "k8s.io/api/core/v1"
+)
+
+func TestInitContainerMissing(t *testing.T) {
+	tests := []struct {
+		name     string
+		pod      corev1.Pod
+		expected bool
+	}{
+		{
+			name: "InitContainer_Already_Inject",
+			pod: corev1.Pod{
+				Spec: corev1.PodSpec{
+					InitContainers: []corev1.Container{
+						{
+							Name: "istio-init",
+						},
+						{
+							Name: initContainerName,
+						},
+					},
+				},
+			},
+			expected: false,
+		},
+		{
+			name: "InitContainer_Absent_1",
+			pod: corev1.Pod{
+				Spec: corev1.PodSpec{
+					InitContainers: []corev1.Container{
+						{
+							Name: "istio-init",
+						},
+					},
+				},
+			},
+			expected: true,
+		},
+		{
+			name: "InitContainer_Absent_2",
+			pod: corev1.Pod{
+				Spec: corev1.PodSpec{},
+			},
+			expected: true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			result := IsInitContainerMissing(test.pod)
+			assert.Equal(t, test.expected, result)
+		})
+	}
+}

pkg/instrumentation/javaagent.go

@@ -26,9 +26,9 @@ const (
 	javaJVMArgument     = " -javaagent:/otel-auto-instrumentation/javaagent.jar"
 )
 
-func injectJavaagent(logger logr.Logger, javaSpec v1alpha1.Java, pod corev1.Pod) corev1.Pod {
+func injectJavaagent(logger logr.Logger, javaSpec v1alpha1.Java, pod corev1.Pod, index int) corev1.Pod {
 	// caller checks if there is at least one container
-	container := &pod.Spec.Containers[0]
+	container := &pod.Spec.Containers[index]
 
 	// inject env vars
 	for _, env := range javaSpec.Env {
@@ -57,21 +57,24 @@ func injectJavaagent(logger logr.Logger, javaSpec v1alpha1.Java, pod corev1.Pod)
 		MountPath: "/otel-auto-instrumentation",
 	})
 
-	pod.Spec.Volumes = append(pod.Spec.Volumes, corev1.Volume{
-		Name: volumeName,
-		VolumeSource: corev1.VolumeSource{
-			EmptyDir: &corev1.EmptyDirVolumeSource{},
-		}})
+	// We just inject Volumes and init containers for the first processed container
+	if IsInitContainerMissing(pod) {
+		pod.Spec.Volumes = append(pod.Spec.Volumes, corev1.Volume{
+			Name: volumeName,
+			VolumeSource: corev1.VolumeSource{
+				EmptyDir: &corev1.EmptyDirVolumeSource{},
+			}})
 
-	pod.Spec.InitContainers = append(pod.Spec.InitContainers, corev1.Container{
-		Name:    initContainerName,
-		Image:   javaSpec.Image,
-		Command: []string{"cp", "/javaagent.jar", "/otel-auto-instrumentation/javaagent.jar"},
-		VolumeMounts: []corev1.VolumeMount{{
-			Name:      volumeName,
-			MountPath: "/otel-auto-instrumentation",
-		}},
-	})
+		pod.Spec.InitContainers = append(pod.Spec.InitContainers, corev1.Container{
+			Name:    initContainerName,
+			Image:   javaSpec.Image,
+			Command: []string{"cp", "/javaagent.jar", "/otel-auto-instrumentation/javaagent.jar"},
+			VolumeMounts: []corev1.VolumeMount{{
+				Name:      volumeName,
+				MountPath: "/otel-auto-instrumentation",
+			}},
+		})
+	}
 
 	return pod
 }

pkg/instrumentation/javaagent_test.go

@@ -174,7 +174,7 @@ func TestInjectJavaagent(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			pod := injectJavaagent(logr.Discard(), test.Java, test.pod)
+			pod := injectJavaagent(logr.Discard(), test.Java, test.pod, 0)
 			assert.Equal(t, test.expected, pod)
 		})
 	}

pkg/instrumentation/nodejs.go

@@ -26,9 +26,9 @@ const (
 	nodeRequireArgument = " --require /otel-auto-instrumentation/autoinstrumentation.js"
 )
 
-func injectNodeJSSDK(logger logr.Logger, nodeJSSpec v1alpha1.NodeJS, pod corev1.Pod) corev1.Pod {
+func injectNodeJSSDK(logger logr.Logger, nodeJSSpec v1alpha1.NodeJS, pod corev1.Pod, index int) corev1.Pod {
 	// caller checks if there is at least one container
-	container := &pod.Spec.Containers[0]
+	container := &pod.Spec.Containers[index]
 
 	// inject env vars
 	for _, env := range nodeJSSpec.Env {
@@ -57,21 +57,24 @@ func injectNodeJSSDK(logger logr.Logger, nodeJSSpec v1alpha1.NodeJS, pod corev1.
 		MountPath: "/otel-auto-instrumentation",
 	})
 
-	pod.Spec.Volumes = append(pod.Spec.Volumes, corev1.Volume{
-		Name: volumeName,
-		VolumeSource: corev1.VolumeSource{
-			EmptyDir: &corev1.EmptyDirVolumeSource{},
-		}})
+	// We just inject Volumes and init containers for the first processed container
+	if IsInitContainerMissing(pod) {
+		pod.Spec.Volumes = append(pod.Spec.Volumes, corev1.Volume{
+			Name: volumeName,
+			VolumeSource: corev1.VolumeSource{
+				EmptyDir: &corev1.EmptyDirVolumeSource{},
+			}})
 
-	pod.Spec.InitContainers = append(pod.Spec.InitContainers, corev1.Container{
-		Name:    initContainerName,
-		Image:   nodeJSSpec.Image,
-		Command: []string{"cp", "-a", "/autoinstrumentation/.", "/otel-auto-instrumentation/"},
-		VolumeMounts: []corev1.VolumeMount{{
-			Name:      volumeName,
-			MountPath: "/otel-auto-instrumentation",
-		}},
-	})
+		pod.Spec.InitContainers = append(pod.Spec.InitContainers, corev1.Container{
+			Name:    initContainerName,
+			Image:   nodeJSSpec.Image,
+			Command: []string{"cp", "-a", "/autoinstrumentation/.", "/otel-auto-instrumentation/"},
+			VolumeMounts: []corev1.VolumeMount{{
+				Name:      volumeName,
+				MountPath: "/otel-auto-instrumentation",
+			}},
+		})
+	}
 
 	return pod
 }

pkg/instrumentation/nodejs_test.go

@@ -174,7 +174,7 @@ func TestInjectNodeJSSDK(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			pod := injectNodeJSSDK(logr.Discard(), test.NodeJS, test.pod)
+			pod := injectNodeJSSDK(logr.Discard(), test.NodeJS, test.pod, 0)
 			assert.Equal(t, test.expected, pod)
 		})
 	}

pkg/instrumentation/podmutator.go

@@ -94,9 +94,17 @@ func (pm *instPodMutator) Mutate(ctx context.Context, ns corev1.Namespace, pod c
 		return pod, nil
 	}
 
+	// We retrieve the annotation for podname
+	var targetContainers = annotationValue(ns.ObjectMeta, pod.ObjectMeta, annotationInjectContainerName)
+
 	// once it's been determined that instrumentation is desired, none exists yet, and we know which instance it should talk to,
 	// we should inject the instrumentation.
-	return pm.sdkInjector.inject(ctx, insts, ns, pod), nil
+	modifiedPod := pod
+	for _, currentContainer := range strings.Split(targetContainers, ",") {
+		modifiedPod = pm.sdkInjector.inject(ctx, insts, ns, modifiedPod, strings.TrimSpace(currentContainer))
+	}
+
+	return modifiedPod, nil
 }
 
 func (pm *instPodMutator) getInstrumentationInstance(ctx context.Context, ns corev1.Namespace, pod corev1.Pod, instAnnotation string) (*v1alpha1.Instrumentation, error) {

pkg/instrumentation/python.go

@@ -30,9 +30,9 @@ const (
 	pythonPathSuffix      = "/otel-auto-instrumentation"
 )
 
-func injectPythonSDK(logger logr.Logger, pythonSpec v1alpha1.Python, pod corev1.Pod) corev1.Pod {
+func injectPythonSDK(logger logr.Logger, pythonSpec v1alpha1.Python, pod corev1.Pod, index int) corev1.Pod {
 	// caller checks if there is at least one container
-	container := &pod.Spec.Containers[0]
+	container := &pod.Spec.Containers[index]
 
 	// inject env vars
 	for _, env := range pythonSpec.Env {
@@ -71,21 +71,24 @@ func injectPythonSDK(logger logr.Logger, pythonSpec v1alpha1.Python, pod corev1.
 		MountPath: "/otel-auto-instrumentation",
 	})
 
-	pod.Spec.Volumes = append(pod.Spec.Volumes, corev1.Volume{
-		Name: volumeName,
-		VolumeSource: corev1.VolumeSource{
-			EmptyDir: &corev1.EmptyDirVolumeSource{},
-		}})
+	// We just inject Volumes and init containers for the first processed container
+	if IsInitContainerMissing(pod) {
+		pod.Spec.Volumes = append(pod.Spec.Volumes, corev1.Volume{
+			Name: volumeName,
+			VolumeSource: corev1.VolumeSource{
+				EmptyDir: &corev1.EmptyDirVolumeSource{},
+			}})
 
-	pod.Spec.InitContainers = append(pod.Spec.InitContainers, corev1.Container{
-		Name:    initContainerName,
-		Image:   pythonSpec.Image,
-		Command: []string{"cp", "-a", "/autoinstrumentation/.", "/otel-auto-instrumentation/"},
-		VolumeMounts: []corev1.VolumeMount{{
-			Name:      volumeName,
-			MountPath: "/otel-auto-instrumentation",
-		}},
-	})
+		pod.Spec.InitContainers = append(pod.Spec.InitContainers, corev1.Container{
+			Name:    initContainerName,
+			Image:   pythonSpec.Image,
+			Command: []string{"cp", "-a", "/autoinstrumentation/.", "/otel-auto-instrumentation/"},
+			VolumeMounts: []corev1.VolumeMount{{
+				Name:      volumeName,
+				MountPath: "/otel-auto-instrumentation",
+			}},
+		})
+	}
 
 	return pod
 }

pkg/instrumentation/python_test.go

@@ -244,7 +244,7 @@ func TestInjectPythonSDK(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			pod := injectPythonSDK(logr.Discard(), test.Python, test.pod)
+			pod := injectPythonSDK(logr.Discard(), test.Python, test.pod, 0)
 			assert.Equal(t, test.expected, pod)
 		})
 	}