Jaeger v2 with OpenTelemetry on Kubernetes

I am trying to setup jaegerv2 with open telemetry on AKS following this

I have followed the exact steps but I am getting this error when the collector pod starts (I have attached the pod logs below)

Kubernetes version: 1.29.15

2025/04/14 14:00:48 application version: git-commit=, git-version=, build-date=
Error: failed to get config: cannot unmarshal the configuration: decoding failed due to the following error(s):
error decoding 'extensions': error reading configuration for "jaeger_query": decoding failed due to the following error(s):
'' has invalid keys: endpoint
2025/04/14 14:00:48 failed to get config: cannot unmarshal the configuration: decoding failed due to the following error(s):
error decoding 'extensions': error reading configuration for "jaeger_query": decoding failed due to the following error(s):
'' has invalid keys: endpoint

The error you're seeing

error decoding 'extensions': error reading configuration for "jaeger_query": decoding failed...
'' has invalid keys: endpoint

happens when the Open Telemetry Collector configuration includes an invalid or deprecated extension block — especially for jaeger_query, which is not a supported extension in Open Telemetry Collector.

Kindly check if the extensions section in your OpenTelemetry Collector config likely contains something like

extensions:
  jaeger_query:
    endpoint: "http://jaeger-query:16687"

If so, then that is causing issue as it is invalid. jaeger_query is not a valid extension type, and endpoint under extensions is not recognized by the Collector schema, hence the decode failure.

What is the fix?

Instead of trying to use jaeger_query as an extension, you should deploy Jaeger separately and then forward traces from the OpenTelemetry Collector to Jaeger's collector service using the exporters.jaeger block.

Assuming you have a working AKS cluster, install Jaeger using Helm-

helm repo add jaegertracing https://jaegertracing.github.io/helm-charts
helm repo update

helm install jaeger jaegertracing/jaeger \
  --namespace observability --create-namespace \
  --set query.enabled=true \
  --set collector.enabled=true \
  --set agent.enabled=true \
  --set collector.service.type=ClusterIP \
  --set query.service.type=LoadBalancer \
  --set storage.type=memory

Deploy OpenTelemetry Collector with correct config (no extensions.jaeger_query)

vim otel-collector.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: otel-collector-config
  namespace: observability
data:
  collector.yaml: |
    receivers:
      otlp:
        protocols:
          grpc:
          http:
    processors:
      batch:
    exporters:
      jaeger:
        endpoint: jaeger-collector.observability.svc.cluster.local:14250
        tls:
          insecure: true
    service:
      pipelines:
        traces:
          receivers: [otlp]
          processors: [batch]
          exporters: [jaeger]

After installing with query.service.type=LoadBalancer, you can access the UI via the external IP

kubectl get svc -n observability jaeger-query

Pods are up as well

do a port forward to the port you set in a separate terminal before sending the trace. In my case

kubectl port-forward svc/otel-collector -n observability 4318:4318

verify the same http://<external-ip> in your browser.

Now you can try to send the traces.