telemetry.tracing config works with deprecated style

[erewok]

Hello,

I'm looking at the (excellent in general) Envoy Gateway docs in order to ship opentelemetry traces to an otel-collector's grpc endpoint. It's in the namespace monitoring at the usual port: 4317.

When I look at the API Reference, it says that host and port are deprecated in favor of BackendRefs, but I can only get it work using the deprecated style.

Here's a commented version of what I mean:

apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyProxy
metadata:
  name: gwclass-tier1
  namespace: gateways
spec:
  mergeGateways: true
  telemetry:
    tracing:
      # sample 100% of requests
      samplingRate: 100
      provider:
        # Deprecated style works ->
        host: otel-collector.monitoring.svc.cluster.local
        port: 4317
        # backendRefs: # Preferred style (commented here) does not work 
        # - name: otel-collector
        #   namespace: monitoring
        #   kind: Service
        #   port: 4317
        type: OpenTelemetry

Is it possible this is due to API versions or something? I was trying to enable debug logs but wasn't sure which logs to enable.

Versions:

• Envoy Gateway: v1.6.2
• crds/httproutes.gateway.networking.k8s.io version: v1.1.1

[zirain]

Without #7694, you need to make sure the appProtocol configed to use grpc.

[erewok]

Thanks for the quick reply! We can wait for a future release if grpc becomes the default, then. Is there more information on setting appProtocol in the docs? (I searched and found it in one spot in API reference).

[zirain]

you should follow this doc.

[zirain]

BTY, the upstream OTel-collecter set it by default.

gateway/test/helm/gateway-addons-helm/e2e.out.yaml

Line 10536 in 73ed4cb

appProtocol: grpc

[erewok]

ah, got it. thank you.

[erewok]

just to follow-up: I updated my otel-collector Service to include appProtocol and I was able to then use backendRefs instead of deprecated host and name:

kind: Service
apiVersion: v1
metadata:
  name: otel-collector
  namespace: monitoring
spec:
  selector:
    app.kubernetes.io/name: opentelemetry-collector
  ports:
  - name: otlp
    protocol: TCP
    port: 4317
    targetPort: 4317
    appProtocol: grpc

Thank you again for the help, @zirain

[arkodg]

@zirain didnt we default to h2 recently ?

[zirain]

yes, in #7694, will be part of v1.7