Set up a proxyless gRPC service mesh on GKE

Preview

This product or feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of the Service Specific Terms. Pre-GA products and features are available "as is" and might have limited support. For more information, see the launch stage descriptions.

This pages describes how to deploy an example proxyless gRPC client and server to a Cloud Service Mesh.

Prerequisites

As a starting point, this guide assumes that you have already:

• Created a GKE cluster and registered it to a fleet.
• Installed the custom resource definitions.

Requirements

This section lists the requirements for supported services:

• gRPC C++ - version 1.62.0 or later
• gRPC Java - version 1.65.0 or later
• gRPC Go - version 1.65.0 or later
• gRPC Python - version 1.65.0 or later

Set up the Service

Deploy a gRPC service:

C++

kubectl apply -f - <<EOF
---
apiVersion: v1
kind: Service
metadata:
  name: helloworld
spec:
  selector:
    app: psm-grpc-server
  ports:
  - port: 50051
    targetPort: 50051
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-server
  labels:
    app: psm-grpc-server
spec:
  replicas: 2
  selector:
    matchLabels:
      app: psm-grpc-server
  template:
    metadata:
      labels:
        app: psm-grpc-server
    spec:
      containers:
      - name: psm-grpc-server
        image: grpc/csm-o11y-example-cpp-server:v1.65.1
        imagePullPolicy: Always
        args:
          - "--port=50051"
        ports:
          - containerPort: 50051
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-server
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image: gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory
EOF

Java

kubectl apply -f - <<EOF
---
apiVersion: v1
kind: Service
metadata:
  name: helloworld
spec:
  selector:
    app: psm-grpc-server
  ports:
  - port: 50051
    targetPort: 50051
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-server
  labels:
    app: psm-grpc-server
spec:
  replicas: 2
  selector:
    matchLabels:
      app: psm-grpc-server
  template:
    metadata:
      labels:
        app: psm-grpc-server
    spec:
      containers:
      - name: psm-grpc-server
        image: grpc/csm-o11y-example-java-server:v1.65.1
        imagePullPolicy: Always
        args:
          - "50051"
          - "9464"
        ports:
          - containerPort: 50051
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-server
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image: gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory
EOF

Go

kubectl apply -f - <<EOF
---
apiVersion: v1
kind: Service
metadata:
  name: helloworld
spec:
  selector:
    app: psm-grpc-server
  ports:
  - port: 50051
    targetPort: 50051
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-server
  labels:
    app: psm-grpc-server
spec:
  replicas: 2
  selector:
    matchLabels:
      app: psm-grpc-server
  template:
    metadata:
      labels:
        app: psm-grpc-server
    spec:
      containers:
      - name: psm-grpc-server
        image: grpc/csm-o11y-example-go-server:v1.65.0
        imagePullPolicy: Always
        args:
          - "--port=50051"
        ports:
          - containerPort: 50051
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-server
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image: gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory
EOF

Python

kubectl apply -f - <<EOF
---
apiVersion: v1
kind: Service
metadata:
  name: helloworld
spec:
  selector:
    app: psm-grpc-server
  ports:
  - port: 50051
    targetPort: 50051
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-server
  labels:
    app: psm-grpc-server
spec:
  replicas: 2
  selector:
    matchLabels:
      app: psm-grpc-server
  template:
    metadata:
      labels:
        app: psm-grpc-server
    spec:
      containers:
      - name: psm-grpc-server
        image: grpc/csm-o11y-example-python-server:latest
        imagePullPolicy: Always
        args:
          - "--port=50051"
        ports:
          - containerPort: 50051
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-server
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image: gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory
EOF

The output is similar to

service/helloworld created
deployment.apps/psm-grpc-server created

1. Verify that the Pods have been created:

   kubectl get pods
   

   The output is similar to

   NAME                               READY   STATUS    RESTARTS   AGE
   psm-grpc-server-65966bf76d-2wwxz   1/1     Running   0          13s
   psm-grpc-server-65966bf76d-nbxd2   1/1     Running   0          13s
   

   Wait for all Pods to be ready and have the Status Running before continuing.

2. Deploy a HTTPRoute:

   kubectl apply -f - <<EOF
   apiVersion: gateway.networking.k8s.io/v1beta1
   kind: HTTPRoute
   metadata:
     name: app1
   spec:
     parentRefs:
     - name: helloworld
       kind: Service
       group: ""
     rules:
     - backendRefs:
       - name: helloworld
         port: 50051
   EOF
   

   This command creates an HTTPRoute called app1 and sends all RPCs to the helloworld service.

   Note that the parentRef service is also helloworld which means our HTTPRoute is attached to this service and will process all RPCs addressed to this service. In case of proxyless gRPC it means any client sending RPCs on a gRPC channel for target xds:///helloworld.default.svc.cluster.local:50051.

3. Verify that the new app1 HTTPRoute has been created:

   kubectl get httproute
   

   The output is similar to

   NAME   HOSTNAMES   AGE
   app1               72s
   

Set up the Client

This sections describes how to use a gRPC client to verify that Cloud Service Mesh is routing traffic correctly in the mesh.

Run a gRPC client and direct it to use the routing configuration specified by the HTTPRoute:

C++

kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-client
  labels:
    app: psm-grpc-client
spec:
  replicas: 1
  selector:
    matchLabels:
      app: psm-grpc-client
  template:
    metadata:
      labels:
        app: psm-grpc-client
    spec:
      containers:
      - name: psm-grpc-client
        image: grpc/csm-o11y-example-cpp-client:v1.65.1
        imagePullPolicy: Always
        args:
          - "--target=xds:///helloworld.default.svc.cluster.local:50051"
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-client
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CONTAINER_NAME
            value: psm-grpc-client
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image:  gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory

EOF

Java

kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-client
  labels:
    app: psm-grpc-client
spec:
  replicas: 1
  selector:
    matchLabels:
      app: psm-grpc-client
  template:
    metadata:
      labels:
        app: psm-grpc-client
    spec:
      containers:
      - name: psm-grpc-client
        image: grpc/csm-o11y-example-java-client:v1.65.1
        imagePullPolicy: Always
        args:
          - "world"
          - "xds:///helloworld.default.svc.cluster.local:50051"
          - "9464"
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-client
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CONTAINER_NAME
            value: psm-grpc-client
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image:  gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory

EOF

Go

kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-client
  labels:
    app: psm-grpc-client
spec:
  replicas: 1
  selector:
    matchLabels:
      app: psm-grpc-client
  template:
    metadata:
      labels:
        app: psm-grpc-client
    spec:
      containers:
      - name: psm-grpc-client
        image: grpc/csm-o11y-example-go-client:v1.65.0
        imagePullPolicy: Always
        args:
          - "--target=xds:///helloworld.default.svc.cluster.local:50051"
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-client
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CONTAINER_NAME
            value: psm-grpc-client
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image:  gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory

EOF

Python

kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  name: psm-grpc-client
  labels:
    app: psm-grpc-client
spec:
  replicas: 1
  selector:
    matchLabels:
      app: psm-grpc-client
  template:
    metadata:
      labels:
        app: psm-grpc-client
    spec:
      containers:
      - name: psm-grpc-client
        image: grpc/csm-o11y-example-python-client:latest
        imagePullPolicy: Always
        args:
          - "--target=xds:///helloworld.default.svc.cluster.local:50051"
        env:
          - name: GRPC_XDS_BOOTSTRAP
            value: "/tmp/grpc-xds/td-grpc-bootstrap.json"
          - name: CSM_WORKLOAD_NAME
            value: psm-grpc-client
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: NAMESPACE_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: CONTAINER_NAME
            value: psm-grpc-client
          - name: OTEL_RESOURCE_ATTRIBUTES
            value: k8s.pod.name=\$(POD_NAME),k8s.namespace.name=\$(NAMESPACE_NAME),k8s.container.name=\$(CONTAINER_NAME)
        volumeMounts:
          - mountPath: /tmp/grpc-xds/
            name: grpc-td-conf
            readOnly: true
      initContainers:
        - name: grpc-td-init
          image:  gcr.io/trafficdirector-prod/td-grpc-bootstrap:0.16.0
          imagePullPolicy: Always
          args:
            - "--output=/tmp/bootstrap/td-grpc-bootstrap.json"
            - "--vpc-network-name=default"
            - "--xds-server-uri=trafficdirector.googleapis.com:443"
            - "--generate-mesh-id"
          volumeMounts:
            - mountPath: /tmp/bootstrap/
              name: grpc-td-conf
      volumes:
        - name: grpc-td-conf
          emptyDir:
            medium: Memory

EOF

The output is similar to

deployment.apps/psm-grpc-client created

Google Cloud Managed Service for Prometheus Setup (Optional)

You can deploy the Google Cloud Managed Service for Prometheus PodMonitoring resource to export the metrics to Cloud Monitoring.

• For servers, run the following command:

  kubectl apply -f - <<EOF
  apiVersion: monitoring.googleapis.com/v1
  kind: PodMonitoring
  metadata:
    name: psm-grpc-server-gmp
  spec:
    selector:
      matchLabels:
        app: psm-grpc-server
    endpoints:
    - port: 9464
      interval: 10s
  EOF
  

• For clients, , run the following command:

  kubectl apply -f - <<EOF
  apiVersion: monitoring.googleapis.com/v1
  kind: PodMonitoring
  metadata:
    name: psm-grpc-client-gmp
  spec:
    selector:
      matchLabels:
        app: psm-grpc-client
    endpoints:
    - port: 9464
      interval: 10s
  EOF
  

  After deploying the PodMonitoring resource, each matching pod's localhost:9464/metrics will be scraped every 10 seconds and will export the results to Cloud Monitoring.

To view the metrics in Cloud Monitoring, perform the following steps:

you can navigate to the Metrics Explorer section of your Google Cloud console, select Prometheus Target > Grpc to find the metrics.

Go to Metrics Explorer

Verify the proxyless gRPC service mesh setup and mesh Observability

1. Check the metrics output from the client Pod:

   kubectl exec $(kubectl get po | grep psm-grpc-client | awk '{print $1;}') -- /usr/bin/curl -s http://localhost:9464/metrics
   

   The output shows the metrics (with the service mesh labels) that were scraped from the endpoint:

   Defaulted container "psm-grpc-client" out of: psm-grpc-client, grpc-td-init (init)
   # HELP exposer_transferred_bytes_total Transferred bytes to metrics services
   # TYPE exposer_transferred_bytes_total counter
   exposer_transferred_bytes_total 36047
   # HELP exposer_scrapes_total Number of times metrics were scraped
   # TYPE exposer_scrapes_total counter
   exposer_scrapes_total 1
   # HELP exposer_request_latencies Latencies of serving scrape requests, in microseconds
   # TYPE exposer_request_latencies summary
   exposer_request_latencies_count 1
   exposer_request_latencies_sum 1246
   exposer_request_latencies{quantile="0.5"} Nan
   exposer_request_latencies{quantile="0.9"} Nan
   exposer_request_latencies{quantile="0.99"} Nan
   # HELP grpc_client_attempt_rcvd_total_compressed_message_size_By Compressed message bytes received per call attempt
   # TYPE grpc_client_attempt_rcvd_total_compressed_message_size_By histogram
   grpc_client_attempt_rcvd_total_compressed_message_size_By_count{csm_mesh_id="gsmmesh-35av-my-cluster-3-us-east7-c-35av6nnbi9jz",csm_remote_workload_canonical_service="unknown",csm_remote_workload_cluster_name="my-cluster-3",csm_remote_workload_location="us-east7-c",csm_remote_workload_name="psm-grpc-server",csm_remote_workload_namespace_name="default",csm_remote_workload_project_id="grpc-testing",csm_remote_workload_type="gcp_kubernetes_engine",csm_workload_canonical_service="unknown",grpc_method="helloworld.Greeter/SayHello",grpc_status="OK",grpc_target="xds:///helloworld.default.svc.cluster.local:50051"} 114 1695445356167
   ...
   

2. Check the metrics output from the server:

   kubectl exec $(kubectl get po | grep psm-grpc-server | awk '{print $1;}' | head -n 1) -- /usr/bin/curl -s http://localhost:9464/metrics
   

   The output shows the metrics (with the service mesh labels) that were scraped from the endpoint:

   Defaulted container "psm-grpc-server" out of: psm-grpc-server, grpc-td-init (init)
   # HELP exposer_transferred_bytes_total Transferred bytes to metrics services
   # TYPE exposer_transferred_bytes_total counter
   exposer_transferred_bytes_total 35945
   # HELP exposer_scrapes_total Number of times metrics were scraped
   # TYPE exposer_scrapes_total counter
   exposer_scrapes_total 1
   # HELP exposer_request_latencies Latencies of serving scrape requests, in microseconds
   # TYPE exposer_request_latencies summary
   exposer_request_latencies_count 1
   exposer_request_latencies_sum 2369
   exposer_request_latencies{quantile="0.5"} Nan
   exposer_request_latencies{quantile="0.9"} Nan
   exposer_request_latencies{quantile="0.99"} Nan
   # HELP target Target metadata
   # TYPE target gauge
   target_info{otel_scope_name="grpc-c++",otel_scope_version="1.62.0-dev",service_name="unknown_service",k8s_pod_name="psm-grpc-server-6f75c8f857-qst5k",k8s_namespace_name="default",k8s_container_name="$(CONTAINER_NAME)",telemetry_sdk_version="1.13.0",telemetry_sdk_name="opentelemetry",telemetry_sdk_language="cpp"} 1 1708157423871
   # HELP grpc_server_call_sent_total_compressed_message_size_bytes Compressed message bytes sent per server call
   # TYPE grpc_server_call_sent_total_compressed_message_size_bytes histogram
   grpc_server_call_sent_total_compressed_message_size_bytes_count{csm_mesh_id="gsmmesh-fogj-my-cluster-us-central1-a-fogjnvmqo8fn",csm_remote_workload_canonical_service="unknown",csm_remote_workload_cluster_name="my-cluster",csm_remote_workload_location="us-central1-a",csm_remote_workload_name="test-workload-name",csm_remote_workload_namespace_name="default",csm_remote_workload_project_id="project-id",csm_remote_workload_type="gcp_kubernetes_engine",csm_workload_canonical_service="unknown",grpc_method="helloworld.Greeter/SayHello",grpc_status="OK",otel_scope_name="grpc-c++",otel_scope_version="1.62.0-dev"} 1796 1708157423871
   …
   

Troubleshoot Cloud Service Mesh observability

This section shows how to troubleshoot common issues.

Metrics are not exported / displayed

Make sure that all binaries involved (both client and server) are set up with Observability.

If you're using the Prometheus exporter, verify that the URL for the Prometheus exporter is set up as expected.

Make sure that the gRPC channels are Cloud Service Mesh enabled. The channels should have a target of the form xds:///. gRPC servers are always enabled for Cloud Service Mesh.

No metrics exported / An attribute value on a metric shows up as unknown

Cloud Service Mesh Observability determines the mesh topological information through environment labels. Make sure that the Pod or service spec for both the client and the service specify all the labels as described in the example.

1. Describe the psm-grpc-server deployment:

   kubectl describe Deployment psm-grpc-server | grep "psm-grpc-server:" -A 12
   

   The output is similar to:

   psm-grpc-server:
   Image:      grpc/csm-example-server:2024-02-13
   Port:       50051/TCP
   Host Port:  0/TCP
   Args:
     --port=50051
   Environment:
     GRPC_XDS_BOOTSTRAP:          /tmp/grpc-xds/td-grpc-bootstrap.json
     POD_NAME:                     (v1:metadata.name)
     NAMESPACE_NAME:               (v1:metadata.namespace)
     CSM_WORKLOAD_NAME:           psm-grpc-server
     OTEL_RESOURCE_ATTRIBUTES:    k8s.pod.name=$(POD_NAME),k8s.namespace.name=$(NAMESPACE_NAME),k8s.container.name=$(CONTAINER_NAME)
   

2. Describe the psm-grpc-client deployment:

   kubectl describe Deployment psm-grpc-client | grep "psm-grpc-client:" -A 12
   

   The output is similar to:

   psm-grpc-client:
   Image:      grpc/csm-example-client:2024-02-13
   Port:       <none>
   Host Port:  <none>
   Args:
     --target=xds:///helloworld.default.svc.cluster.local:50051
   Environment:
     GRPC_XDS_BOOTSTRAP:          /tmp/grpc-xds/td-grpc-bootstrap.json
     CSM_WORKLOAD_NAME:           test-workload-name
     POD_NAME:                     (v1:metadata.name)
     NAMESPACE_NAME:               (v1:metadata.namespace)
     CONTAINER_NAME:              psm-grpc-client