[dotnet-auto] Add support for musl based images

.chloggen/1849-dotnet-auto-musl-support.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. operator, target allocator, github action)
+component: autoinstrumentation
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: .NET Automatic Instrumentation support for Alpine-based images 
+
+# One or more tracking issues related to the change
+issues: [1849]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

README.md

@@ -254,9 +254,14 @@ Python:
 instrumentation.opentelemetry.io/inject-python: "true"
 ```
 
-DotNet:
+.NET:
+.NET auto-instrumentation also honors an annotation that will be used to set the .NET [Runtime Identifiers](https://learn.microsoft.com/en-us/dotnet/core/rid-catalog)(RIDs).
+Currently, only two RIDs are supported: `linux-x64` and `linux-musl-x64`.
+By default `linux-x64` is used.
 ```bash
 instrumentation.opentelemetry.io/inject-dotnet: "true"
+instrumentation.opentelemetry.io/otel-dotnet-auto-runtime: "linux-x64" # for Linux glibc based images, this is default value and can be omitted
+instrumentation.opentelemetry.io/otel-dotnet-auto-runtime: "linux-musl-x64"  # for Linux musl based images
 ```
 
 Go:

pkg/instrumentation/annotation.go

@@ -27,6 +27,7 @@ const (
 	annotationInjectNodeJS        = "instrumentation.opentelemetry.io/inject-nodejs"
 	annotationInjectPython        = "instrumentation.opentelemetry.io/inject-python"
 	annotationInjectDotNet        = "instrumentation.opentelemetry.io/inject-dotnet"
+	annotationDotNetRuntime       = "instrumentation.opentelemetry.io/otel-dotnet-auto-runtime"
 	annotationInjectGo            = "instrumentation.opentelemetry.io/inject-go"
 	annotationGoExecPath          = "instrumentation.opentelemetry.io/otel-go-auto-target-exe"
 	annotationInjectSdk           = "instrumentation.opentelemetry.io/inject-sdk"

pkg/instrumentation/dotnet.go

@@ -33,13 +33,20 @@ const (
 	envDotNetOTelAutoHome               = "OTEL_DOTNET_AUTO_HOME"
 	dotNetCoreClrEnableProfilingEnabled = "1"
 	dotNetCoreClrProfilerID             = "{918728DD-259F-4A6A-AC2B-B85E1B658318}"
-	dotNetCoreClrProfilerPath           = "/otel-auto-instrumentation/linux-x64/OpenTelemetry.AutoInstrumentation.Native.so"
+	dotNetCoreClrProfilerGlibcPath      = "/otel-auto-instrumentation/linux-x64/OpenTelemetry.AutoInstrumentation.Native.so"
+	dotNetCoreClrProfilerMuslPath       = "/otel-auto-instrumentation/linux-musl-x64/OpenTelemetry.AutoInstrumentation.Native.so"
 	dotNetAdditionalDepsPath            = "/otel-auto-instrumentation/AdditionalDeps"
 	dotNetOTelAutoHomePath              = "/otel-auto-instrumentation"
 	dotNetSharedStorePath               = "/otel-auto-instrumentation/store"
 	dotNetStartupHookPath               = "/otel-auto-instrumentation/net/OpenTelemetry.AutoInstrumentation.StartupHook.dll"
 )
 
+// Supported .NET runtime identifiers (https://learn.microsoft.com/en-us/dotnet/core/rid-catalog), can be set by instrumentation.opentelemetry.io/inject-dotnet.
+const (
+	dotNetRuntimeLinuxGlibc = "linux-x64"
+	dotNetRuntimeLinuxMusl  = "linux-musl-x64"
+)
+
 func injectDotNetSDK(dotNetSpec v1alpha1.DotNet, pod corev1.Pod, index int) (corev1.Pod, error) {
 
 	// caller checks if there is at least one container.
@@ -62,6 +69,17 @@ func injectDotNetSDK(dotNetSpec v1alpha1.DotNet, pod corev1.Pod, index int) (cor
 		return pod, errors.New("OTEL_DOTNET_AUTO_HOME environment variable is already set in the .NET instrumentation spec")
 	}
 
+	runtime := pod.Annotations[annotationDotNetRuntime]
+	coreClrProfilerPath := ""
+	switch runtime {
+	case "", dotNetRuntimeLinuxGlibc:
+		coreClrProfilerPath = dotNetCoreClrProfilerGlibcPath
+	case dotNetRuntimeLinuxMusl:
+		coreClrProfilerPath = dotNetCoreClrProfilerMuslPath
+	default:
+		return pod, fmt.Errorf("provided instrumentation.opentelemetry.io/dotnet-runtime annotation value '%s' is not supported", runtime)
+	}
+
 	// inject .NET instrumentation spec env vars.
 	for _, env := range dotNetSpec.Env {
 		idx := getIndexOfEnv(container.Env, env.Name)
@@ -79,7 +97,7 @@ func injectDotNetSDK(dotNetSpec v1alpha1.DotNet, pod corev1.Pod, index int) (cor
 
 	setDotNetEnvVar(container, envDotNetCoreClrProfiler, dotNetCoreClrProfilerID, doNotConcatEnvValues)
 
-	setDotNetEnvVar(container, envDotNetCoreClrProfilerPath, dotNetCoreClrProfilerPath, doNotConcatEnvValues)
+	setDotNetEnvVar(container, envDotNetCoreClrProfilerPath, coreClrProfilerPath, doNotConcatEnvValues)
 
 	setDotNetEnvVar(container, envDotNetStartupHook, dotNetStartupHookPath, concatEnvValues)
 

pkg/instrumentation/dotnet_test.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/open-telemetry/opentelemetry-operator/apis/v1alpha1"
 )
@@ -85,7 +86,7 @@ func TestInjectDotNetSDK(t *testing.T) {
 								},
 								{
 									Name:  envDotNetCoreClrProfilerPath,
-									Value: dotNetCoreClrProfilerPath,
+									Value: dotNetCoreClrProfilerGlibcPath,
 								},
 								{
 									Name:  envDotNetStartupHook,
@@ -365,6 +366,211 @@ func TestInjectDotNetSDK(t *testing.T) {
 			},
 			err: fmt.Errorf("OTEL_DOTNET_AUTO_HOME environment variable is already set in the .NET instrumentation spec"),
 		},
+		{
+			name:   "runtime linux-x64",
+			DotNet: v1alpha1.DotNet{Image: "foo/bar:1", Env: []corev1.EnvVar{}, Resources: testResourceRequirements},
+			pod: corev1.Pod{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{
+						{},
+					},
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{
+						annotationDotNetRuntime: dotNetRuntimeLinuxGlibc,
+					},
+				},
+			},
+			expected: corev1.Pod{
+				Spec: corev1.PodSpec{
+					Volumes: []corev1.Volume{
+						{
+							Name: volumeName,
+							VolumeSource: corev1.VolumeSource{
+								EmptyDir: &corev1.EmptyDirVolumeSource{
+									SizeLimit: &defaultVolumeLimitSize,
+								},
+							},
+						},
+					},
+					InitContainers: []corev1.Container{
+						{
+							Name:    initContainerName,
+							Image:   "foo/bar:1",
+							Command: []string{"cp", "-a", "/autoinstrumentation/.", "/otel-auto-instrumentation/"},
+							VolumeMounts: []corev1.VolumeMount{{
+								Name:      volumeName,
+								MountPath: "/otel-auto-instrumentation",
+							}},
+							Resources: testResourceRequirements,
+						},
+					},
+					Containers: []corev1.Container{
+						{
+							VolumeMounts: []corev1.VolumeMount{
+								{
+									Name:      volumeName,
+									MountPath: "/otel-auto-instrumentation",
+								},
+							},
+							Env: []corev1.EnvVar{
+								{
+									Name:  envDotNetCoreClrEnableProfiling,
+									Value: dotNetCoreClrEnableProfilingEnabled,
+								},
+								{
+									Name:  envDotNetCoreClrProfiler,
+									Value: dotNetCoreClrProfilerID,
+								},
+								{
+									Name:  envDotNetCoreClrProfilerPath,
+									Value: dotNetCoreClrProfilerGlibcPath,
+								},
+								{
+									Name:  envDotNetStartupHook,
+									Value: dotNetStartupHookPath,
+								},
+								{
+									Name:  envDotNetAdditionalDeps,
+									Value: dotNetAdditionalDepsPath,
+								},
+								{
+									Name:  envDotNetOTelAutoHome,
+									Value: dotNetOTelAutoHomePath,
+								},
+								{
+									Name:  envDotNetSharedStore,
+									Value: dotNetSharedStorePath,
+								},
+							},
+						},
+					},
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{
+						annotationDotNetRuntime: dotNetRuntimeLinuxGlibc,
+					},
+				},
+			},
+			err: nil,
+		},
+		{
+			name:   "runtime linux-musl-x64",
+			DotNet: v1alpha1.DotNet{Image: "foo/bar:1", Env: []corev1.EnvVar{}, Resources: testResourceRequirements},
+			pod: corev1.Pod{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{
+						{},
+					},
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{
+						annotationDotNetRuntime: dotNetRuntimeLinuxMusl,
+					},
+				},
+			},
+			expected: corev1.Pod{
+				Spec: corev1.PodSpec{
+					Volumes: []corev1.Volume{
+						{
+							Name: volumeName,
+							VolumeSource: corev1.VolumeSource{
+								EmptyDir: &corev1.EmptyDirVolumeSource{
+									SizeLimit: &defaultVolumeLimitSize,
+								},
+							},
+						},
+					},
+					InitContainers: []corev1.Container{
+						{
+							Name:    initContainerName,
+							Image:   "foo/bar:1",
+							Command: []string{"cp", "-a", "/autoinstrumentation/.", "/otel-auto-instrumentation/"},
+							VolumeMounts: []corev1.VolumeMount{{
+								Name:      volumeName,
+								MountPath: "/otel-auto-instrumentation",
+							}},
+							Resources: testResourceRequirements,
+						},
+					},
+					Containers: []corev1.Container{
+						{
+							VolumeMounts: []corev1.VolumeMount{
+								{
+									Name:      volumeName,
+									MountPath: "/otel-auto-instrumentation",
+								},
+							},
+							Env: []corev1.EnvVar{
+								{
+									Name:  envDotNetCoreClrEnableProfiling,
+									Value: dotNetCoreClrEnableProfilingEnabled,
+								},
+								{
+									Name:  envDotNetCoreClrProfiler,
+									Value: dotNetCoreClrProfilerID,
+								},
+								{
+									Name:  envDotNetCoreClrProfilerPath,
+									Value: dotNetCoreClrProfilerMuslPath,
+								},
+								{
+									Name:  envDotNetStartupHook,
+									Value: dotNetStartupHookPath,
+								},
+								{
+									Name:  envDotNetAdditionalDeps,
+									Value: dotNetAdditionalDepsPath,
+								},
+								{
+									Name:  envDotNetOTelAutoHome,
+									Value: dotNetOTelAutoHomePath,
+								},
+								{
+									Name:  envDotNetSharedStore,
+									Value: dotNetSharedStorePath,
+								},
+							},
+						},
+					},
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{
+						annotationDotNetRuntime: dotNetRuntimeLinuxMusl,
+					},
+				},
+			},
+			err: nil,
+		},
+		{
+			name:   "runtime not-supported",
+			DotNet: v1alpha1.DotNet{Image: "foo/bar:1", Env: []corev1.EnvVar{}, Resources: testResourceRequirements},
+			pod: corev1.Pod{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{
+						{},
+					},
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{
+						annotationDotNetRuntime: "not-supported",
+					},
+				},
+			},
+			expected: corev1.Pod{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{
+						{},
+					},
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{
+						annotationDotNetRuntime: "not-supported",
+					},
+				},
+			},
+			err: fmt.Errorf("provided instrumentation.opentelemetry.io/dotnet-runtime annotation value 'not-supported' is not supported"),
+		},
 	}
 
 	for _, test := range tests {

pkg/instrumentation/podmutator_test.go

@@ -910,7 +910,8 @@ func TestMutatePod(t *testing.T) {
 			pod: corev1.Pod{
 				ObjectMeta: metav1.ObjectMeta{
 					Annotations: map[string]string{
-						annotationInjectDotNet: "true",
+						annotationInjectDotNet:  "true",
+						annotationDotNetRuntime: dotNetRuntimeLinuxMusl,
 					},
 				},
 				Spec: corev1.PodSpec{
@@ -924,7 +925,8 @@ func TestMutatePod(t *testing.T) {
 			expected: corev1.Pod{
 				ObjectMeta: metav1.ObjectMeta{
 					Annotations: map[string]string{
-						annotationInjectDotNet: "true",
+						annotationInjectDotNet:  "true",
+						annotationDotNetRuntime: dotNetRuntimeLinuxMusl,
 					},
 				},
 				Spec: corev1.PodSpec{
@@ -971,7 +973,7 @@ func TestMutatePod(t *testing.T) {
 								},
 								{
 									Name:  envDotNetCoreClrProfilerPath,
-									Value: dotNetCoreClrProfilerPath,
+									Value: dotNetCoreClrProfilerMuslPath,
 								},
 								{
 									Name:  envDotNetStartupHook,

pkg/instrumentation/sdk_test.go

@@ -888,7 +888,7 @@ func TestInjectDotNet(t *testing.T) {
 						},
 						{
 							Name:  envDotNetCoreClrProfilerPath,
-							Value: dotNetCoreClrProfilerPath,
+							Value: dotNetCoreClrProfilerGlibcPath,
 						},
 						{
 							Name:  envDotNetStartupHook,

tests/e2e-instrumentation/instrumentation-dotnet-musl/00-install-collector.yaml

@@ -0,0 +1,32 @@
+apiVersion: opentelemetry.io/v1alpha1
+kind: OpenTelemetryCollector
+metadata:
+  name: sidecar
+spec:
+  mode: sidecar
+  config: |
+    receivers:
+      otlp:
+        protocols:
+          grpc:
+          http:
+    processors:
+
+    exporters:
+      logging:
+
+    service:
+      pipelines:
+        traces:
+          receivers: [otlp]
+          processors: []
+          exporters: [logging]
+---
+apiVersion: kuttl.dev/v1beta1
+kind: TestStep
+commands:
+  # Annotate the namespace to allow the application to run using an specific group and user in OpenShift
+  # https://docs.openshift.com/dedicated/authentication/managing-security-context-constraints.html
+  # This annotation has no effect in Kubernetes
+  - command: kubectl annotate namespace ${NAMESPACE} openshift.io/sa.scc.uid-range=1000/1000 --overwrite
+  - command: kubectl annotate namespace ${NAMESPACE} openshift.io/sa.scc.supplemental-groups=2000/1000 --overwrite