Cloud Service Mesh by example: canary deployments


In this tutorial, you walk through a common use case: rolling out a canary deployment with Cloud Service Mesh using Istio APIs.

What is a canary deployment?

A canary deployment routes a small percentage of traffic to a new version of a microservice, then gradually increases that percentage while phasing out and retiring the old version. If something goes wrong during this process, traffic can be switched back to the earlier version. With Cloud Service Mesh, you can route traffic to ensure that new services are introduced safely.

You can read more about canary testing in Application deployment and testing strategies.

Costs

In this document, you use the following billable components of Google Cloud:

To generate a cost estimate based on your projected usage, use the pricing calculator. New Google Cloud users might be eligible for a free trial.

When you finish this tutorial, you can avoid ongoing costs by deleting the resources you created. For more information, see Clean up.

Before you begin

Deploy Online Boutique

  1. Set the current context for kubectl to the cluster where you plan to deploy Online Boutique. The command depends on whether you provisioned Cloud Service Mesh on a GKE cluster or a Kubernetes cluster outside GKE:

    GKE on Google Cloud

    gcloud container clusters get-credentials CLUSTER_NAME  \
        --project=PROJECT_ID \
        --zone=CLUSTER_LOCATION 
    

    GKE outside Google Cloud

    kubectl config use-context CLUSTER_NAME 
    
  2. Create the namespace for the sample application and the ingress gateway:

    kubectl create namespace onlineboutique
    
  3. Label the onlineboutique namespace to automatically inject Envoy proxies. Follow the steps on how to enable automatic sidecar injection.

  4. Deploy the sample app. For this tutorial, you deploy Online Boutique, a microservice demo app.

    kubectl apply \
    -n onlineboutique \
    -f https://raw.githubusercontent.com/GoogleCloudPlatform/anthos-service-mesh-samples/main/docs/shared/online-boutique/kubernetes-manifests.yaml
    
  5. Add a label version=v1 to the productcatalog deployment by running the following command:

    kubectl patch deployments/productcatalogservice -p '{"spec":{"template":{"metadata":{"labels":{"version":"v1"}}}}}' \
    -n onlineboutique
    

    View the services that you deployed:

    kubectl get pods -n onlineboutique
    

    Expected output:

    NAME                                     READY   STATUS    RESTARTS   AGE
    adservice-85598d856b-m84m6               2/2     Running   0          2m7s
    cartservice-c77f6b866-m67vd              2/2     Running   0          2m8s
    checkoutservice-654c47f4b6-hqtqr         2/2     Running   0          2m10s
    currencyservice-59bc889674-jhk8z         2/2     Running   0          2m8s
    emailservice-5b9fff7cb8-8nqwz            2/2     Running   0          2m10s
    frontend-77b88cc7cb-mr4rp                2/2     Running   0          2m9s
    loadgenerator-6958f5bc8b-55q7w           2/2     Running   0          2m8s
    paymentservice-68dd9755bb-2jmb7          2/2     Running   0          2m9s
    productcatalogservice-84f95c95ff-c5kl6   2/2     Running   0          114s
    recommendationservice-64dc9dfbc8-xfs2t   2/2     Running   0          2m9s
    redis-cart-5b569cd47-cc2qd               2/2     Running   0          2m7s
    shippingservice-5488d5b6cb-lfhtt         2/2     Running   0          2m7s
    

    A 2/2 in the READY column indicates that a pod is up and running with an Envoy proxy successfully injected.

  6. Deploy your VirtualService and DestinationRule for v1 of productcatalog:

     kubectl apply -f destination-vs-v1.yaml -n onlineboutique
    
    apiVersion: networking.istio.io/v1beta1
    kind: DestinationRule
    metadata:
      name: productcatalogservice
    spec:
      host: productcatalogservice
      subsets:
      - labels:
          version: v1
        name: v1
    ---
    apiVersion: networking.istio.io/v1beta1
    kind: VirtualService
    metadata:
      name: productcatalogservice
    spec:
      hosts:
      - productcatalogservice
      http:
      - route:
        - destination:
            host: productcatalogservice
            subset: v1

    Note that only v1 is present in the resources.

  7. Visit the application in your browser using the external IP address of your ingress gateway:

    kubectl get services -n GATEWAY_NAMESPACE
    

This next section tours the Cloud Service Mesh UI and show how you can view your metrics.

View your services in Google Cloud console

  1. In Google Cloud console, go to the Google Kubernetes Engine (GKE) Enterprise edition Services page.

    Go to Google Kubernetes Engine (GKE) Enterprise edition Services

  2. By default, you view your services in the List view.

    The Table Overview lets you observe all your services, as well as important metrics at a glance.

  3. In the top right, click Topology. Here you can view your services and their interaction with each other.

    You can expand Services and view the Requests per second for each of your services by hovering over on them with your cursor.

  4. Navigate back to the Table View.

  5. In the Services Table, select productcatalogservice. This takes you to an overview of your service.

  6. On the left side of the screen, click Traffic.

  7. Ensure 100% of the incoming traffic to productcatalogservice goes to the workload service.

The next section goes through creating a v2 of the productcatalog service.

Deploy v2 of a service

  1. For this tutorial, productcatalogservice-v2 introduces a 3-second latency into requests with the EXTRA_LATENCY field. This simulates a regression in the new version of the service.

    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: productcatalogservice-v2
    spec:
      selector:
        matchLabels:
          app: productcatalogservice
      template:
        metadata:
          labels:
            app: productcatalogservice
            version: v2
        spec:
          containers:
          - env:
            - name: PORT
              value: '3550'
            - name: EXTRA_LATENCY
              value: 3s
            name: server
            image: gcr.io/google-samples/microservices-demo/productcatalogservice:v0.3.6
            livenessProbe:
              exec:
                command: ["/bin/grpc_health_probe", "-addr=:3550"]
            ports:
            - containerPort: 3550
            readinessProbe:
              exec:
                command: ["/bin/grpc_health_probe", "-addr=:3550"]
            resources:
              limits:
                cpu: 200m
                memory: 128Mi
              requests:
                cpu: 100m
                memory: 64Mi
          terminationGracePeriodSeconds: 5

    Apply this resource to the onlineboutique namespace.

    kubectl apply -f productcatalog-v2.yaml -n onlineboutique
    
  2. Check on your application pods.

    kubectl get pods -n onlineboutique
    

    Expected output:

    NAME                                     READY   STATUS    RESTARTS   AGE
    adservice-85598d856b-8wqfd                  2/2     Running   0          25h
    cartservice-c77f6b866-7jwcr                 2/2     Running   0          25h
    checkoutservice-654c47f4b6-n8c6x            2/2     Running   0          25h
    currencyservice-59bc889674-l5xw2            2/2     Running   0          25h
    emailservice-5b9fff7cb8-jjr89               2/2     Running   0          25h
    frontend-77b88cc7cb-bwtk4                   2/2     Running   0          25h
    loadgenerator-6958f5bc8b-lqmnw              2/2     Running   0          25h
    paymentservice-68dd9755bb-dckrj             2/2     Running   0          25h
    productcatalogservice-84f95c95ff-ddhjv      2/2     Running   0          25h
    productcatalogservice-v2-6df4cf5475-9lwjb   2/2     Running   0          8s
    recommendationservice-64dc9dfbc8-7s7cx      2/2     Running   0          25h
    redis-cart-5b569cd47-vw7lw                  2/2     Running   0          25h
    shippingservice-5488d5b6cb-dj5gd            2/2     Running   0          25h
    

    Note that there are now two productcatalogservices listed.

  3. Use DestinationRule to specify the subsets of a service. In this scenario, there is a subset for v1 and then a separate subset for v2 of productcatalogservice.

    apiVersion: networking.istio.io/v1beta1
    kind: DestinationRule
    metadata:
      name: productcatalogservice
    spec:
      host: productcatalogservice
      subsets:
      - labels:
          version: v1
        name: v1
      - labels:
          version: v2
        name: v2

    Note the labels field. The versions of productcatalogservice are distinguished after the traffic is routed by the VirtualService.

    Apply the DestinationRule:

    kubectl apply -f destination-v1-v2.yaml -n onlineboutique
    

Split traffic between v1 and v2

  1. Use VirtualService to define a small percentage of the traffic to direct to v2 of the productcatalogservice.

    apiVersion: networking.istio.io/v1beta1
    kind: VirtualService
    metadata:
      name: productcatalogservice
    spec:
      hosts:
      - productcatalogservice
      http:
      - route:
        - destination:
            host: productcatalogservice
            subset: v1
          weight: 75
        - destination:
            host: productcatalogservice
            subset: v2
          weight: 25

    The subset field indicates the version, and the weight field indicates the percentage split of traffic. 75% of traffic goes to v1 of productcatalog, and 25% goes to v2.

    Apply the VirtualService:

    kubectl apply -f vs-split-traffic.yaml -n onlineboutique
    

If you visit the EXTERNAL_IP of the cluster's ingress, you should notice that periodically, the frontend is slower to load.

In the next section, explore the traffic split in Google Cloud console.

Observe the traffic split in Google Cloud console

  1. Return to Google Cloud console and go to the GKE Enterprise Services page. Go to GKE Enterprise Services

  2. In the top right, click Topology.

    Expand the productcatalogservice workload and note the productcatalogservice and productcatalogservice-v2 deployments.

  3. Return to the Table View.

  4. Click productcatalogservice in the Services Table.

  5. Return to Traffic on the left navigation bar.

  6. Note that the incoming traffic is split between v1 and v2 by the percentage specified in the VirtualService file, and that there are 2 workloads of the productcatalog service.

    On the right side of the page, you see Requests, Error Rate, and Latency Metrics. With Cloud Service Mesh, each service has these metrics outlined to provide you with observability metrics.

Roll out or roll back to a version

After observing the metrics during a canary deployment, you can complete the roll out the new service version, or roll back to the original service version by leveraging the VirtualService resource.

Roll out

After you are satisfied with the behavior of a v2 service, you can incrementally increase the percentage of traffic directed to the v2 service. Eventually, traffic can be 100% directed to the new service in the VirtualService resource you created above by removing the traffic split from that resource.

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: productcatalogservice
spec:
  hosts:
  - productcatalogservice
  http:
  - route:
    - destination:
        host: productcatalogservice
        subset: v2

To direct all the traffic to v2 of productcatalogservice:

kubectl apply -f vs-v2.yaml -n onlineboutique

Roll back

If you need to roll back to the v1 service, apply the destination-vs-v1.yaml from earlier. This directs traffic only to v1 of productcatalogservice.

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: productcatalogservice
spec:
  hosts:
  - productcatalogservice
  http:
  - route:
    - destination:
        host: productcatalogservice
        subset: v1

To direct all the traffic to v1 of productcatalogservice:

kubectl apply -f vs-v1.yaml -n onlineboutique

Clean up

To avoid incurring charges to your Google Cloud account for the resources used in this tutorial, either delete the project that contains the resources, or keep the project and delete the individual resources.

To avoid incurring continuing charges to your Google Cloud account for the resources used in this tutorial, you can either delete the project or delete the individual resources.

Delete the project

In Cloud Shell, delete the project:

gcloud projects delete PROJECT_ID

Delete the resources

If you want to prevent additional charges, delete the cluster:

gcloud container clusters delete  CLUSTER_NAME  \
  --project=PROJECT_ID \
  --zone=CLUSTER_LOCATION 

If you registered your cluster with fleet using gcloud container fleet memberships (rather than --enable-fleet or --fleet-project during cluster creation) then remove the stale membership:

gcloud container fleet memberships delete  MEMBERSHIP  \
  --project=PROJECT_ID

If you want to keep your cluster configured for Cloud Service Mesh but remove the Online Boutique sample:

  1. Delete the application namespaces:

    kubectl delete -f namespace onlineboutique
    

    Expected output:

    namespace "onlineboutique" deleted
    
  2. Delete the service entries:

    kubectl delete -f https://raw.githubusercontent.com/GoogleCloudPlatform/microservices-demo/main/istio-manifests/frontend.yaml -n onlineboutique
    kubectl delete -f https://raw.githubusercontent.com/GoogleCloudPlatform/microservices-demo/main/istio-manifests/frontend-gateway.yaml -n onlineboutique
    

    Expected output:

    serviceentry.networking.istio.io "allow-egress-googleapis" deleted
    serviceentry.networking.istio.io "allow-egress-google-metadata" deleted
    

What's next