Instrumenting Node.js applications with EDOT SDKs on Kubernetes

Ensure the OpenTelemetry Operator and Instrumentation object exist

Ensure you have successfully installed the OpenTelemetry Operator, and confirm that the following Instrumentation object exists in the system:

 $ kubectl get instrumentation -n opentelemetry-operator-system NAME AGE ENDPOINT elastic-instrumentation 107s http://opentelemetry-kube-stack-daemon-collector.opentelemetry-operator-system.svc.cluster.local:4318 

Enable auto-instrumentation for your Node.js application

Enable auto-instrumentation of your Node.js application using one of the following methods:

• Edit your application workload definition and include the annotation under spec.template.metadata.annotations:

   kind: Deployment metadata: name: nodejs-app namespace: nodejs-ns spec: ... template: metadata: ... annotations: instrumentation.opentelemetry.io/inject-nodejs: opentelemetry-operator-system/elastic-instrumentation ... 

• Alternatively, add the annotation at namespace level to apply auto-instrumentation in all Pods of the namespace:

   kubectl annotate namespace nodejs-ns instrumentation.opentelemetry.io/inject-nodejs=opentelemetry-operator-system/elastic-instrumentation 

Restart your application

Once the annotation has been set, restart the application to create new Pods and inject the instrumentation libraries:

 kubectl rollout restart deployment nodejs-app -n nodejs-ns 

Verify auto-instrumentation resources in the Pods

Verify the auto-instrumentation resources are injected in the Pods:

Run a kubectl describe of one of your application Pods and check:

• There should be an init container named opentelemetry-auto-instrumentation-nodejs in the Pod. For example:

   $ kubectl describe pod nodejs-app-8d84c47b8-8h5z2 -n nodejs-ns Name: nodejs-app-8d84c47b8-8h5z2 Namespace: nodejs-ns ... ... Init Containers: opentelemetry-auto-instrumentation-nodejs: Container ID: containerd://cbf67d7ca1bd62c25614b905a11e81405bed6fd215f2df21f84b90fd0279230b Image: docker.elastic.co/observability/elastic-otel-node:0.5.0 Command: cp -r /autoinstrumentation/. /otel-auto-instrumentation-nodejs State: Terminated Reason: Completed Exit Code: 0 Started: Wed, 13 Nov 2024 15:47:02 +0100 Finished: Wed, 13 Nov 2024 15:47:03 +0100 Ready: True Restart Count: 0 Environment: <none> Mounts: /otel-auto-instrumentation-nodejs from opentelemetry-auto-instrumentation-nodejs (rw) /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-swhn5 (ro) 

• The main container of the deployment loads the SDK through the NODE_OPTIONS environment variable:

   ... Containers: nodejs-app: Environment: ... NODE_OPTIONS: --require /otel-auto-instrumentation-nodejs/autoinstrumentation.js OTEL_SERVICE_NAME: nodejs-app OTEL_EXPORTER_OTLP_ENDPOINT: http://opentelemetry-kube-stack-daemon-collector.opentelemetry-operator-system.svc.cluster.local:4318 ... 

  Ensure the environment variable OTEL_EXPORTER_OTLP_ENDPOINT points to a valid endpoint and there's network communication between the Pod and the endpoint.

• The Pod has an EmptyDir volume named opentelemetry-auto-instrumentation-nodejs mounted in both the main and the init containers in path /otel-auto-instrumentation-nodejs.

   Init Containers: opentelemetry-auto-instrumentation-nodejs: ... Mounts: /otel-auto-instrumentation-nodejs from opentelemetry-auto-instrumentation-nodejs (rw) Containers: nodejs-app: ... Mounts: /otel-auto-instrumentation-nodejs from opentelemetry-auto-instrumentation-nodejs (rw) ... Volumes: ... opentelemetry-auto-instrumentation-nodejs: Type: EmptyDir (a temporary directory that shares a pod's lifetime) 

Confirm data is flowing to Kibana

Confirm data is flowing to Kibana:

• Open Observability → Applications → Service inventory, and determine if:

  • The application appears in the list of services (nodejs-app in the example).
  • The application shows transactions and metrics.
  Note

  You may need to generate traffic to your application to see spans and metrics.

• For application container logs, open Kibana Discover and filter for your Pods' logs. In the provided example, you could filter for them with either of the following:

  • k8s.deployment.name: "nodejs-app" (adapt the query filter to your use case).
  • k8s.pod.name: nodejs-app* (adapt the query filter to your use case).

Note that the container logs are not provided by the instrumentation library, but by the DaemonSet collector deployed as part of the operator installation.