OpenTelemetry Collector's OTLP gRPC receiver config on Envoy / Contour

1-otel-collector.yaml

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: otel-collector-conf
  namespace: monitoring
  labels:
    app: opentelemetry
    component: otel-collector-conf
data:
  otel-collector-config: |
    receivers:
      otlp:
        protocols:
          grpc:
            tls_settings:
              cert_file: /tls/cert.pem
              key_file: /tls/key.pem
          http:
    processors:
      batch:
      memory_limiter:
        # Same as --mem-ballast-size-mib CLI argument
        ballast_size_mib: 1024
        # 80% of maximum memory
        limit_mib: 1600
        # 25% of limit
        spike_limit_mib: 512
        check_interval: 5s
    extensions:
      health_check: {}
      zpages:
        endpoint: "0.0.0.0:55679"  # default was localhost only!
    exporters:
      logging:
        logLevel: debug
      honeycomb:
        api_key: "$HONEYCOMB_API_KEY"
        dataset: "apps"
        api_url: "https://api.honeycomb.io"
    service:
      extensions: [health_check, zpages]
      pipelines:
        traces:
          receivers: [otlp]
          processors: [memory_limiter, batch]
          exporters: [logging, honeycomb]
---
apiVersion: v1
kind: Service
metadata:
  name: otel-collector
  namespace: monitoring
  labels:
    app: opentelemetry
    component: otel-collector
spec:
  ports:
  - name: zpages
    port: 55679
    # when proxied: http://localhost:8001/api/v1/namespaces/monitoring/services/http:otel-collector:55679/proxy/debug/tracez
  - name: otlp-grpc # Default endpoint for OpenTelemetry receiver.
    port: 55680
  - name: otlp-http
    port: 55681
  - name: jaeger-grpc # Default endpoing for Jaeger gRPC receiver
    port: 14250
  - name: jaeger-thrift-http # Default endpoint for Jaeger HTTP receiver.
    port: 14268
  - name: zipkin # Default endpoint for Zipkin receiver.
    port: 9411
  - name: metrics # Default endpoint for querying metrics.
    port: 8888
  selector:
    component: otel-collector
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: otel-collector
  namespace: monitoring
  labels:
    app: opentelemetry
    component: otel-collector
spec:
  selector:
    matchLabels:
      app: opentelemetry
      component: otel-collector
  minReadySeconds: 5
  progressDeadlineSeconds: 120
  replicas: 2
  template:
    metadata:
      labels:
        app: opentelemetry
        component: otel-collector
    spec:
      containers:
      - command:
          - "/otelcontribcol"
          - "--log-level=DEBUG"
          - "--config=/conf/otel-collector-config.yaml"
          # Memory Ballast size should be max 1/3 to 1/2 of memory.
          - "--mem-ballast-size-mib=1024"
        #image: otel/opentelemetry-collector-dev:latest
        image: otel/opentelemetry-collector-contrib:0.11.0
        name: otel-collector
        envFrom:
        - secretRef:
            name: otel-collector
        resources:
          limits:
            cpu: 1
            memory: 2Gi
          requests:
            cpu: 200m
            memory: 400Mi
        ports:
        - containerPort: 55679 # Default endpoint for ZPages.
        - containerPort: 55680 # OTLP gRPC receiver.
        - containerPort: 55681 # OTLP HTML/JSON receiver.
        - containerPort: 14250 # Default endpoint for Jaeger HTTP receiver.
        - containerPort: 14268 # Default endpoint for Jaeger HTTP receiver.
        - containerPort: 9411  # Default endpoint for Zipkin receiver.
        - containerPort: 8888  # Default endpoint for querying metrics.
        volumeMounts:
        - name: otel-collector-config-vol
          mountPath: /conf
        - name: otel-tls
          mountPath: /tls
        livenessProbe:
          httpGet:
            path: /
            port: 13133 # Health Check extension default port.
        readinessProbe:
          httpGet:
            path: /
            port: 13133 # Health Check extension default port.
      volumes:
        - name: otel-collector-config-vol
          configMap:
            name: otel-collector-conf
            items:
              - key: otel-collector-config
                path: otel-collector-config.yaml
        - name: otel-tls
          secret:
            secretName: otel-wildcard
            items:
              - key: tls.crt
                path: cert.pem
              - key: tls.key
                path: key.pem

2-otlp-grpc.yaml

# Routing for OTLP (gRPC) traffic wrapped in HTTP/2 TLS
#
# As of 2020-10-06:
#  - the yages echo app works when terminating TLS at Envoy (h2c), but
#  - otel does not and needs a TLS passthrough (h2).
---
apiVersion: projectcontour.io/v1
kind: HTTPProxy
metadata:
  name: otel-collector
  namespace: monitoring
  annotations:
    kubernetes.io/ingress.class: "contour"
  labels:
    app: opentelemetry
    component: otel-collector
spec:
  virtualhost:
    fqdn: otel.staging.test
    tls:
      #secretName: otel-wildcard
      passthrough: true
  tcpproxy:
    services:
    - name: otel-collector
      port: 55680
      # tls: HTTP/1 TLS
      # h2:  HTTP/2 TLS
      # h2c: HTTP/2 cleartext
      protocol: h2

https://projectcontour.io/docs/v1.3.0/httpproxy/#tcp-proxying

Incidentally the config file alone works locally too inside of this:

docker run --rm --interactive --tty --volume `pwd`:/conf otel/opentelemetry-collector-contrib:0.11.0 /otelcontribcol --config /conf/otel-config.yaml --log-level=DEBUG --publish 55680:55680 --publish 55679:55679