Route traffic from Cloud Run Services to Cloud Service Mesh workloads on GKE

This page shows you how to securely route network traffic from Cloud Run Services to Cloud Service Mesh workloads on GKE to use Istio APIs and make use of a fully-managed Envoy sidecar.

Before you begin

The following sections assume that you have a GKE cluster with Cloud Service Mesh enabled.

If you don't have a GKE Service deployed, use the following command to deploy a sample service:

cat <<EOF > /tmp/service.yaml
apiVersion: v1
kind: Service
metadata:
  name: ads
spec:
  ports:
  - port: 9999
    targetPort: 8000
  selector:
    run: ads
  type: ClusterIP
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ads
spec:
  replicas: 1
  selector:
    matchLabels:
      run: ads
  template:
    metadata:
      labels:
        run: ads
    spec:
      containers:
      - image: docker.io/waip/simple-http:v1.0.1
        name: my-http2-svc
        ports:
        - protocol: TCP
          containerPort: 8000
      securityContext:
        fsGroup: 1337
EOF
kubectl apply -f /tmp/service.yaml

Configure a Custom Domain for VirtualService hosts

A virtual service defines traffic routing rules. Any matched traffic is then sent to a named destination service

  1. Create a new managed zone:

    gcloud dns managed-zones create ZONE_NAME \
  --description="zone for service mesh routes" \
  --dns-name=DNS_SUFFIX. \
  --networks=default \
  --visibility=private

    where:

    • ZONE_NAME is a name for your zone (example: 'prod').
    • DNS_SUFFIX is any valid DNS host (example: 'mesh.private').

  2. Create a resource record set:

    IP=10.0.0.1
gcloud dns record-sets create '*.'"DNS_SUFFIX." --type=A --zone="ZONE_NAME" \
  --rrdatas=10.0.0.1 --ttl 3600

    Ensure the IP (RFC 1918 required) is unused. Alternatively, reserve a static internal IP.

  3. Export a VirtualService for External Cloud Run Clients:

    cat <<EOF > virtual-service.yaml
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: VIRTUAL_SERVICE_NAME
  namespace: NAMESPACE
spec:
  hosts:
  - GKE_SERVICE_NAME.DNS_SUFFIX
  gateways:
  - external-mesh
  http:
  - route:
    - destination:
        host: GKE_SERVICE_NAME
EOF
kubectl apply -f virtual-service.yaml

    where:

    • VIRTUAL_SERVICE_NAME is a name for your VirtualService.
    • NAMESPACE is default if you're using the provided example service; otherwise, replace NAMESPACE with your namespace name.
    • GKE_SERVICE_NAME is ads if you're using the provided example service; otherwise, replace GKE_SERVICE_NAME with a name for your GKE service.

While it is feasible to add an external-mesh gateway as a target to a pre-existing VirtualService, you should establish a distinct VirtualService to export a Kubernetes service to external Cloud Run clients. Having a separate VirtualService facilitates the management of exported services and their configurations without affecting existing GKE clients. Additionally, some fields in VirtualServices are disregarded for mesh external VirtualServices but continue to function as anticipated for GKE services. So managing and troubleshooting VirtualServices separately may be advantageous.

For GKE clients to also receive the VirtualService configuration, the mesh or mesh/default gateway must be added.

The mesh external VirtualService must be defined in the same namespace as the Kubernetes Service in the VirtualService destination.

Configure a Cloud Run Service to join a service mesh

To join a Cloud Run Service to a service mesh, perform the following steps:

  1. Determine the mesh ID backing the Cloud Service Mesh GKE cluster:

    MESH=$(kubectl get controlplanerevision --namespace istio-system -o json | jq -r '.items[0].metadata.annotations["mesh.cloud.google.com/external-mesh"]')

  2. Deploy a Cloud Run Service using the mesh ID, making sure to also connect to the cluster's VPC network:

    gcloud alpha run deploy --mesh "$MESH" --network default \
  mesh-svc --image=fortio/fortio \
  --region=REGION --project=PROJECT_ID --no-allow-unauthenticated

  3. Verify that the Cloud Run service is able to send a request to the GKE workload:

    TEST_SERVICE_URL=$(gcloud run services describe mesh-svc --region REGION --format="value(status.url)" --project=PROJECT_ID)

curl -H "Authorization: Bearer $(gcloud auth print-identity-token)" "$TEST_SERVICE_URL/fortio/fetch/GKE_SERVICE_NAME.DNS_SUFFIX"

    The output should be a valid HTTP 200 response.

Troubleshooting

This section shows you how to troubleshoot common errors with Cloud Service Mesh and Cloud Run.

Cloud Run Sidecar Logs

Envoy errors are logged in Cloud Logging.

For example an error such as the following will be logged if the Cloud Run service account is not given the trafficdirector client role in the mesh project:

StreamAggregatedResources gRPC config stream to trafficdirector.googleapis.com:443 closed: 7, Permission 'trafficdirector.networks.getConfigs' denied on resource '//trafficdirector.googleapis.com/projects/525300120045/networks/mesh:test-mesh/nodes/003fb3e0c8927482de85f052444d5e1cd4b3956e82b00f255fbea1e114e1c0208dbd6a19cc41694d2a271d1ab04b63ce7439492672de4499a92bb979853935b03d0ad0' (or it may not exist).

CSDS

The trafficdirector client state can be retrieved using CSDS:

gcloud alpha container fleet mesh debug proxy-status --membership=<CLUSTER_MEMBERSHIP> --location=<CLUSTER_LOCATION>
External Clients:
....

What's next