Add resource attributes to collector sidecar

README.md

@@ -164,6 +164,8 @@ spec:
 EOF
 ```
 
+When using sidecar mode the OpenTelemetry collector container will have the environment variable `OTEL_RESOURCE_ATTRIBUTES`set with Kubernetes resource attributes, ready to be consumed by the [resourcedetection](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/processor/resourcedetectionprocessor) processor.
+
 ### OpenTelemetry auto-instrumentation injection
 
 The operator can inject and configure OpenTelemetry auto-instrumentation libraries. Currently Java, NodeJS and Python are supported.

pkg/constants/env.go

@@ -0,0 +1,28 @@
+// 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 constants
+
+const (
+	EnvOTELServiceName          = "OTEL_SERVICE_NAME"
+	EnvOTELExporterOTLPEndpoint = "OTEL_EXPORTER_OTLP_ENDPOINT"
+	EnvOTELResourceAttrs        = "OTEL_RESOURCE_ATTRIBUTES"
+	EnvOTELPropagators          = "OTEL_PROPAGATORS"
+	EnvOTELTracesSampler        = "OTEL_TRACES_SAMPLER"
+	EnvOTELTracesSamplerArg     = "OTEL_TRACES_SAMPLER_ARG"
+
+	EnvPodName  = "OTEL_RESOURCE_ATTRIBUTES_POD_NAME"
+	EnvPodUID   = "OTEL_RESOURCE_ATTRIBUTES_POD_UID"
+	EnvNodeName = "OTEL_RESOURCE_ATTRIBUTES_NODE_NAME"
+)

pkg/instrumentation/sdk.go

@@ -31,22 +31,12 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	"github.com/open-telemetry/opentelemetry-operator/apis/v1alpha1"
+	"github.com/open-telemetry/opentelemetry-operator/pkg/constants"
 )
 
 const (
 	volumeName        = "opentelemetry-auto-instrumentation"
 	initContainerName = "opentelemetry-auto-instrumentation"
-
-	envOTELServiceName          = "OTEL_SERVICE_NAME"
-	envOTELExporterOTLPEndpoint = "OTEL_EXPORTER_OTLP_ENDPOINT"
-	envOTELResourceAttrs        = "OTEL_RESOURCE_ATTRIBUTES"
-	envOTELPropagators          = "OTEL_PROPAGATORS"
-	envOTELTracesSampler        = "OTEL_TRACES_SAMPLER"
-	envOTELTracesSamplerArg     = "OTEL_TRACES_SAMPLER_ARG"
-
-	envPodName  = "OTEL_RESOURCE_ATTRIBUTES_POD_NAME"
-	envPodUID   = "OTEL_RESOURCE_ATTRIBUTES_POD_UID"
-	envNodeName = "OTEL_RESOURCE_ATTRIBUTES_NODE_NAME"
 )
 
 // inject a new sidecar container to the given pod, based on the given OpenTelemetryCollector.
@@ -101,18 +91,18 @@ func (i *sdkInjector) injectCommonEnvVar(otelinst v1alpha1.Instrumentation, pod
 func (i *sdkInjector) injectCommonSDKConfig(ctx context.Context, otelinst v1alpha1.Instrumentation, ns corev1.Namespace, pod corev1.Pod) corev1.Pod {
 	container := &pod.Spec.Containers[0]
 	resourceMap := i.createResourceMap(ctx, otelinst, ns, pod)
-	idx := getIndexOfEnv(container.Env, envOTELServiceName)
+	idx := getIndexOfEnv(container.Env, constants.EnvOTELServiceName)
 	if idx == -1 {
 		container.Env = append(container.Env, corev1.EnvVar{
-			Name:  envOTELServiceName,
+			Name:  constants.EnvOTELServiceName,
 			Value: chooseServiceName(pod, resourceMap),
 		})
 	}
 	if otelinst.Spec.Exporter.Endpoint != "" {
-		idx = getIndexOfEnv(container.Env, envOTELExporterOTLPEndpoint)
+		idx = getIndexOfEnv(container.Env, constants.EnvOTELExporterOTLPEndpoint)
 		if idx == -1 {
 			container.Env = append(container.Env, corev1.EnvVar{
-				Name:  envOTELExporterOTLPEndpoint,
+				Name:  constants.EnvOTELExporterOTLPEndpoint,
 				Value: otelinst.Spec.Endpoint,
 			})
 		}
@@ -121,45 +111,45 @@ func (i *sdkInjector) injectCommonSDKConfig(ctx context.Context, otelinst v1alph
 	// Some attributes might be empty, we should get them via k8s downward API
 	if resourceMap[string(semconv.K8SPodNameKey)] == "" {
 		container.Env = append(container.Env, corev1.EnvVar{
-			Name: envPodName,
+			Name: constants.EnvPodName,
 			ValueFrom: &corev1.EnvVarSource{
 				FieldRef: &corev1.ObjectFieldSelector{
 					FieldPath: "metadata.name",
 				},
 			},
 		})
-		resourceMap[string(semconv.K8SPodNameKey)] = fmt.Sprintf("$(%s)", envPodName)
+		resourceMap[string(semconv.K8SPodNameKey)] = fmt.Sprintf("$(%s)", constants.EnvPodName)
 	}
 	if otelinst.Spec.Resource.AddK8sUIDAttributes {
 		if resourceMap[string(semconv.K8SPodUIDKey)] == "" {
 			container.Env = append(container.Env, corev1.EnvVar{
-				Name: envPodUID,
+				Name: constants.EnvPodUID,
 				ValueFrom: &corev1.EnvVarSource{
 					FieldRef: &corev1.ObjectFieldSelector{
 						FieldPath: "metadata.uid",
 					},
 				},
 			})
-			resourceMap[string(semconv.K8SPodUIDKey)] = fmt.Sprintf("$(%s)", envPodUID)
+			resourceMap[string(semconv.K8SPodUIDKey)] = fmt.Sprintf("$(%s)", constants.EnvPodUID)
 		}
 	}
 	if resourceMap[string(semconv.K8SNodeNameKey)] == "" {
 		container.Env = append(container.Env, corev1.EnvVar{
-			Name: envNodeName,
+			Name: constants.EnvNodeName,
 			ValueFrom: &corev1.EnvVarSource{
 				FieldRef: &corev1.ObjectFieldSelector{
 					FieldPath: "spec.nodeName",
 				},
 			},
 		})
-		resourceMap[string(semconv.K8SNodeNameKey)] = fmt.Sprintf("$(%s)", envNodeName)
+		resourceMap[string(semconv.K8SNodeNameKey)] = fmt.Sprintf("$(%s)", constants.EnvNodeName)
 	}
 
-	idx = getIndexOfEnv(container.Env, envOTELResourceAttrs)
+	idx = getIndexOfEnv(container.Env, constants.EnvOTELResourceAttrs)
 	resStr := resourceMapToStr(resourceMap)
 	if idx == -1 {
 		container.Env = append(container.Env, corev1.EnvVar{
-			Name:  envOTELResourceAttrs,
+			Name:  constants.EnvOTELResourceAttrs,
 			Value: resStr,
 		})
 	} else {
@@ -169,27 +159,27 @@ func (i *sdkInjector) injectCommonSDKConfig(ctx context.Context, otelinst v1alph
 		container.Env[idx].Value += resStr
 	}
 
-	idx = getIndexOfEnv(container.Env, envOTELPropagators)
+	idx = getIndexOfEnv(container.Env, constants.EnvOTELPropagators)
 	if idx == -1 && len(otelinst.Spec.Propagators) > 0 {
 		propagators := *(*[]string)((unsafe.Pointer(&otelinst.Spec.Propagators)))
 		container.Env = append(container.Env, corev1.EnvVar{
-			Name:  envOTELPropagators,
+			Name:  constants.EnvOTELPropagators,
 			Value: strings.Join(propagators, ","),
 		})
 	}
 
-	idx = getIndexOfEnv(container.Env, envOTELTracesSampler)
+	idx = getIndexOfEnv(container.Env, constants.EnvOTELTracesSampler)
 	// configure sampler only if it is configured in the CR
 	if idx == -1 && otelinst.Spec.Sampler.Type != "" {
-		idxSamplerArg := getIndexOfEnv(container.Env, envOTELTracesSamplerArg)
+		idxSamplerArg := getIndexOfEnv(container.Env, constants.EnvOTELTracesSamplerArg)
 		if idxSamplerArg == -1 {
 			container.Env = append(container.Env, corev1.EnvVar{
-				Name:  envOTELTracesSampler,
+				Name:  constants.EnvOTELTracesSampler,
 				Value: string(otelinst.Spec.Sampler.Type),
 			})
 			if otelinst.Spec.Sampler.Argument != "" {
 				container.Env = append(container.Env, corev1.EnvVar{
-					Name:  envOTELTracesSamplerArg,
+					Name:  constants.EnvOTELTracesSamplerArg,
 					Value: otelinst.Spec.Sampler.Argument,
 				})
 			}
@@ -223,7 +213,7 @@ func chooseServiceName(pod corev1.Pod, resources map[string]string) string {
 func (i *sdkInjector) createResourceMap(ctx context.Context, otelinst v1alpha1.Instrumentation, ns corev1.Namespace, pod corev1.Pod) map[string]string {
 	// get existing resources env var and parse it into a map
 	existingRes := map[string]bool{}
-	existingResourceEnvIdx := getIndexOfEnv(pod.Spec.Containers[0].Env, envOTELResourceAttrs)
+	existingResourceEnvIdx := getIndexOfEnv(pod.Spec.Containers[0].Env, constants.EnvOTELResourceAttrs)
 	if existingResourceEnvIdx > -1 {
 		existingResArr := strings.Split(pod.Spec.Containers[0].Env[existingResourceEnvIdx].Value, ",")
 		for _, kv := range existingResArr {

pkg/sidecar/attributes.go

@@ -0,0 +1,120 @@
+// 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 sidecar contains operations related to sidecar manipulation (Add, update, remove).
+package sidecar
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"go.opentelemetry.io/otel/attribute"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+
+	"github.com/open-telemetry/opentelemetry-operator/pkg/constants"
+)
+
+const resourceAttributesEnvName = "OTEL_RESOURCE_ATTRIBUTES"
+
+type podReferences struct {
+	replicaset *appsv1.ReplicaSet
+	deployment *appsv1.Deployment
+}
+
+// getResourceAttributesEnv returns a list of environment variables. The list contains OTEL_RESOURCE_ATTRIBUTES and additional environment variables that use Kubernetes downward API to read pod specification.
+// see: https://kubernetes.io/docs/tasks/inject-data-application/environment-variable-expose-pod-information/
+func getResourceAttributesEnv(ns corev1.Namespace, podReferences podReferences) []corev1.EnvVar {
+
+	var envvars []corev1.EnvVar
+
+	attributes := map[attribute.Key]string{
+		semconv.K8SPodNameKey:       fmt.Sprintf("$(%s)", constants.EnvPodName),
+		semconv.K8SPodUIDKey:        fmt.Sprintf("$(%s)", constants.EnvPodUID),
+		semconv.K8SNodeNameKey:      fmt.Sprintf("$(%s)", constants.EnvNodeName),
+		semconv.K8SNamespaceNameKey: ns.Name,
+	}
+
+	if podReferences.deployment != nil {
+		attributes[semconv.K8SDeploymentUIDKey] = string(podReferences.deployment.UID)
+		attributes[semconv.K8SDeploymentNameKey] = string(podReferences.deployment.Name)
+	}
+
+	if podReferences.replicaset != nil {
+		attributes[semconv.K8SReplicaSetUIDKey] = string(podReferences.replicaset.UID)
+		attributes[semconv.K8SReplicaSetNameKey] = string(podReferences.replicaset.Name)
+	}
+
+	envvars = append(envvars, corev1.EnvVar{
+		Name: constants.EnvPodName,
+		ValueFrom: &corev1.EnvVarSource{
+			FieldRef: &corev1.ObjectFieldSelector{
+				FieldPath: "metadata.name",
+			},
+		},
+	})
+
+	envvars = append(envvars, corev1.EnvVar{
+		Name: constants.EnvPodUID,
+		ValueFrom: &corev1.EnvVarSource{
+			FieldRef: &corev1.ObjectFieldSelector{
+				FieldPath: "metadata.uid",
+			},
+		},
+	})
+
+	envvars = append(envvars, corev1.EnvVar{
+		Name: constants.EnvNodeName,
+		ValueFrom: &corev1.EnvVarSource{
+			FieldRef: &corev1.ObjectFieldSelector{
+				FieldPath: "spec.nodeName",
+			},
+		},
+	})
+
+	envvars = append(envvars, corev1.EnvVar{
+		Name:  resourceAttributesEnvName,
+		Value: mapToValue(attributes),
+	})
+
+	return envvars
+}
+
+func mapToValue(attributesMap map[attribute.Key]string) string {
+	var parts []string
+
+	// Sort it to make it predictable
+	keys := make([]string, 0, len(attributesMap))
+	for k := range attributesMap {
+		keys = append(keys, string(k))
+	}
+	sort.Strings(keys)
+
+	for _, key := range keys {
+		parts = append(parts, fmt.Sprintf("%s=%s", key, attributesMap[attribute.Key(key)]))
+	}
+	return strings.Join(parts, ",")
+}
+
+// check if container doesn't have already the OTEL_RESOURCE_ATTRIBUTES, we don't want to override it if it's already specified.
+func hasResourceAttributeEnvVar(envvars []corev1.EnvVar) bool {
+	for _, env := range envvars {
+		if env.Name == resourceAttributesEnvName {
+			return true
+		}
+	}
+	return false
+}