feat: inject instrumentation relevant env vars using webhook

api/odigos/v1alpha1/instrumentationconfig_types.go

@@ -3,6 +3,7 @@ package v1alpha1
 import (
 	"github.com/odigos-io/odigos/api/odigos/v1alpha1/instrumentationrules"
 	"github.com/odigos-io/odigos/common"
+	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -62,6 +63,15 @@ type InstrumentationConfigStatus struct {
 	Conditions []metav1.Condition `json:"conditions,omitempty" patchStrategy:"merge" protobuf:"bytes,1,rep,name=conditions"`
 }
 
+func (in *InstrumentationConfigStatus) GetRuntimeDetailsForContainer(container v1.Container) *RuntimeDetailsByContainer {
+	for _, runtimeDetails := range in.RuntimeDetailsByContainer {
+		if runtimeDetails.ContainerName == container.Name {
+			return &runtimeDetails
+		}
+	}
+	return nil
+}
+
 // Config for the OpenTelemeetry SDKs that should be applied to a workload.
 // The workload is identified by the owner reference
 type InstrumentationConfigSpec struct {

common/envOverwrite/overwriter.go

@@ -182,6 +182,10 @@ func ValToAppend(envName string, sdk common.OtelSdk) (string, bool) {
 	return valToAppend, true
 }
 
+func GetPossibleValuesPerEnv(env string) map[common.OtelSdk]string {
+	return EnvValuesMap[env].values
+}
+
 // due to a bug we had with the env overwriter logic,
 // some patched values were recorded incorrectly into the workload annotation for original value.
 // they include odigos values (/var/odigos/...) as if they were the original value in the manifest,
@@ -214,3 +218,20 @@ func CleanupEnvValueFromOdigosAdditions(envVarName string, envVarValue string) s
 	sanitizedEnvValue := strings.Join(cleanParts, overwriteMetadata.delim)
 	return sanitizedEnvValue
 }
+
+func AppendOdigosAdditionsToEnvVar(envName string, envFromContainerRuntimeValue string, desiredOdigosAddition string) *string {
+	envValues, ok := EnvValuesMap[envName]
+	if !ok {
+		// Odigos does not manipulate this environment variable, so ignore it
+		return nil
+	}
+
+	// In case observedValue is exists but empty, we just need to set the desiredOdigosAddition without delim before
+	if strings.TrimSpace(envFromContainerRuntimeValue) == "" {
+		return &desiredOdigosAddition
+	} else {
+		// In case observedValue is not empty, we need to append the desiredOdigosAddition with the delim
+		mergedEnvValue := envFromContainerRuntimeValue + envValues.delim + desiredOdigosAddition
+		return &mergedEnvValue
+	}
+}

instrumentor/controllers/instrumentationdevice/pods_webhook.go

@@ -5,8 +5,10 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/go-logr/logr"
 	"github.com/odigos-io/odigos/api/k8sconsts"
 	"github.com/odigos-io/odigos/common"
+	webhookenvinjector "github.com/odigos-io/odigos/instrumentor/internal/webhook_env_injector"
 	containerutils "github.com/odigos-io/odigos/k8sutils/pkg/container"
 	"github.com/odigos-io/odigos/k8sutils/pkg/workload"
 	"go.opentelemetry.io/otel/attribute"
@@ -35,6 +37,8 @@ type PodsWebhook struct {
 var _ webhook.CustomDefaulter = &PodsWebhook{}
 
 func (p *PodsWebhook) Default(ctx context.Context, obj runtime.Object) error {
+	logger := log.FromContext(ctx)
+
 	pod, ok := obj.(*corev1.Pod)
 	if !ok {
 		return fmt.Errorf("expected a Pod but got a %T", obj)
@@ -44,70 +48,39 @@ func (p *PodsWebhook) Default(ctx context.Context, obj runtime.Object) error {
 		pod.Annotations = map[string]string{}
 	}
 
-	serviceName, podWorkload := p.getServiceNameForEnv(ctx, pod)
-
 	// Inject ODIGOS environment variables into all containers
-	injectOdigosEnvVars(pod, podWorkload, serviceName)
-
-	return nil
+	return p.injectOdigosEnvVars(ctx, logger, pod)
 }
 
-// checks for the service name on the annotation, or fallback to the workload name
-func (p *PodsWebhook) getServiceNameForEnv(ctx context.Context, pod *corev1.Pod) (*string, *workload.PodWorkload) {
-
-	logger := log.FromContext(ctx)
-
-	podWorkload, err := workload.PodWorkloadObject(ctx, pod)
-	if err != nil {
-		logger.Error(err, "failed to extract pod workload details from pod. skipping OTEL_SERVICE_NAME injection")
-		return nil, nil
-	}
+func (p *PodsWebhook) injectOdigosEnvVars(ctx context.Context, logger logr.Logger, pod *corev1.Pod) error {
+	// Environment variables that remain consistent across all containers
+	commonEnvVars := getCommonEnvVars()
 
-	req, err := admission.RequestFromContext(ctx)
+	// In certain scenarios, the raw request can be utilized to retrieve missing details, like the namespace.
+	// For example, prior to Kubernetes version 1.24 (see https://github.com/kubernetes/kubernetes/pull/94637),
+	// namespaced objects could be sent to admission webhooks with empty namespaces during their creation.
+	admissionRequest, err := admission.RequestFromContext(ctx)
 	if err != nil {
-		logger.Error(err, "failed to get admission request from context")
-		return nil, nil
+		return fmt.Errorf("failed to get admission request: %w", err)
 	}
-	podWorkload.Namespace = req.Namespace
 
-	workloadObj, err := workload.GetWorkloadObject(ctx, client.ObjectKey{Namespace: podWorkload.Namespace, Name: podWorkload.Name}, podWorkload.Kind, p.Client)
+	podWorkload, err := workload.PodWorkloadObject(ctx, pod)
 	if err != nil {
-		logger.Error(err, "failed to get workload object from cache. cannot check for workload annotation. using workload name as OTEL_SERVICE_NAME")
-		return &podWorkload.Name, podWorkload
+		return fmt.Errorf("failed to extract pod workload details from pod: %w", err)
 	}
-	resolvedServiceName := workload.ExtractServiceNameFromAnnotations(workloadObj.GetAnnotations(), podWorkload.Name)
-	return &resolvedServiceName, podWorkload
-}
-
-func injectOdigosEnvVars(pod *corev1.Pod, podWorkload *workload.PodWorkload, serviceName *string) {
 
-	// Common environment variables that do not change across containers
-	commonEnvVars := []corev1.EnvVar{
-		{
-			Name: k8sconsts.OdigosEnvVarNamespace,
-			ValueFrom: &corev1.EnvVarSource{
-				FieldRef: &corev1.ObjectFieldSelector{
-					FieldPath: "metadata.namespace",
-				},
-			},
-		},
-		{
-			Name: k8sconsts.OdigosEnvVarPodName,
-			ValueFrom: &corev1.EnvVarSource{
-				FieldRef: &corev1.ObjectFieldSelector{
-					FieldPath: "metadata.name",
-				},
-			},
-		},
+	if podWorkload.Namespace == "" {
+		if admissionRequest.Namespace != "" {
+			// If the namespace is available in the admission request, set it in the podWorkload.Namespace.
+			podWorkload.Namespace = admissionRequest.Namespace
+		} else {
+			// It is a case that not supposed to happen, but if it does, return an error.
+			return fmt.Errorf("namespace is empty for pod %s/%s, Skipping Injection of ODIGOS environment variables", pod.Namespace, pod.Name)
+		}
 	}
 
+	var serviceName *string
 	var serviceNameEnv *corev1.EnvVar
-	if serviceName != nil {
-		serviceNameEnv = &corev1.EnvVar{
-			Name:  otelServiceNameEnvVarName,
-			Value: *serviceName,
-		}
-	}
 
 	for i := range pod.Spec.Containers {
 		container := &pod.Spec.Containers[i]
@@ -117,31 +90,43 @@ func injectOdigosEnvVars(pod *corev1.Pod, podWorkload *workload.PodWorkload, ser
 			continue
 		}
 
+		webhookenvinjector.InjectOdigosAgentEnvVars(ctx, p.Client, logger, *podWorkload, container, pl, otelsdk)
+
 		// Check if the environment variables are already present, if so skip inject them again.
 		if envVarsExist(container.Env, commonEnvVars) {
 			continue
 		}
 
-		containerNameEnv := corev1.EnvVar{
-			Name:  k8sconsts.OdigosEnvVarContainerName,
-			Value: container.Name,
-		}
-
-		resourceAttributes := getResourceAttributes(podWorkload, container.Name)
-		resourceAttributesEnvValue := getResourceAttributesEnvVarValue(resourceAttributes)
-
+		containerNameEnv := corev1.EnvVar{Name: k8sconsts.OdigosEnvVarContainerName, Value: container.Name}
 		container.Env = append(container.Env, append(commonEnvVars, containerNameEnv)...)
 
-		if serviceNameEnv != nil && shouldInjectServiceName(pl, otelsdk) {
+		if shouldInjectServiceName(pl, otelsdk) {
+			// Ensure the serviceName is fetched only once per pod
+			if serviceName == nil {
+				serviceName = p.getServiceNameForEnv(ctx, logger, podWorkload)
+			}
+			// Initialize serviceNameEnv only once per pod if serviceName is valid
+			if serviceName != nil && serviceNameEnv == nil {
+				serviceNameEnv = &corev1.EnvVar{
+					Name:  otelServiceNameEnvVarName,
+					Value: *serviceName,
+				}
+			}
+
 			if !otelNameExists(container.Env) {
 				container.Env = append(container.Env, *serviceNameEnv)
 			}
-			container.Env = append(container.Env, corev1.EnvVar{
-				Name:  otelResourceAttributesEnvVarName,
-				Value: resourceAttributesEnvValue,
-			})
 		}
+
+		resourceAttributes := getResourceAttributes(podWorkload, container.Name)
+		resourceAttributesEnvValue := getResourceAttributesEnvVarValue(resourceAttributes)
+
+		container.Env = append(container.Env, corev1.EnvVar{
+			Name:  otelResourceAttributesEnvVarName,
+			Value: resourceAttributesEnvValue,
+		})
 	}
+	return nil
 }
 
 func envVarsExist(containerEnv []corev1.EnvVar, commonEnvVars []corev1.EnvVar) bool {
@@ -222,3 +207,35 @@ func shouldInjectServiceName(pl common.ProgrammingLanguage, otelsdk common.OtelS
 	}
 	return false
 }
+
+func getCommonEnvVars() []corev1.EnvVar {
+	return []corev1.EnvVar{
+		{
+			Name: k8sconsts.OdigosEnvVarNamespace,
+			ValueFrom: &corev1.EnvVarSource{
+				FieldRef: &corev1.ObjectFieldSelector{
+					FieldPath: "metadata.namespace",
+				},
+			},
+		},
+		{
+			Name: k8sconsts.OdigosEnvVarPodName,
+			ValueFrom: &corev1.EnvVarSource{
+				FieldRef: &corev1.ObjectFieldSelector{
+					FieldPath: "metadata.name",
+				},
+			},
+		},
+	}
+}
+
+// checks for the service name on the annotation, or fallback to the workload name
+func (p *PodsWebhook) getServiceNameForEnv(ctx context.Context, logger logr.Logger, podWorkload *workload.PodWorkload) *string {
+	workloadObj, err := workload.GetWorkloadObject(ctx, client.ObjectKey{Namespace: podWorkload.Namespace, Name: podWorkload.Name}, podWorkload.Kind, p.Client)
+	if err != nil {
+		logger.Error(err, "failed to get workload object from cache. cannot check for workload annotation. using workload name as OTEL_SERVICE_NAME")
+		return &podWorkload.Name
+	}
+	resolvedServiceName := workload.ExtractServiceNameFromAnnotations(workloadObj.GetAnnotations(), podWorkload.Name)
+	return &resolvedServiceName
+}