Install in-cluster Cloud Service Mesh on GKE

Note: This guide only supports Cloud Service Mesh with Istio APIs and does not support Google Cloud APIs. For more information see, Cloud Service Mesh overview.

This page explains how to install unmanaged, in-cluster Cloud Service Mesh on GKE:

• Run asmcli to do a new installation of Cloud Service Mesh 1.23.4-asm.1.
• Optionally, deploy an ingress gateway.
• Deploy or redeploy your workloads to inject sidecar proxies.

Note that for Kubernetes workloads on Google Cloud, we recommend provisioning a managed control plane

For instructions to prepare an offline installation of Cloud Service Mesh, see Prepare an offline installation of Cloud Service Mesh You will need to specify the --offline and --output_dir options when running asmcli install.

Limitations

Note the following limitations:

• All Cloud Service Mesh clusters for one mesh must be registered to the same fleet at all times to use Cloud Service Mesh. Other clusters in the project of a Cloud Service Mesh cluster must not be registered to a different fleet.

• For GKE Autopilot clusters, only managed Cloud Service Mesh is supported. Cloud Service Mesh support for GKE Autopilot is only available with versions 1.21.3+.

• The asmcli tool must have access to the Google Kubernetes Engine (GKE) endpoint. You can configure access through a "jump" server, such as a Compute Engine VM within the Virtual Private Cloud (VPC) giving specific access.

Before you begin

Before you begin, make sure that you:

• Review the prerequisites.
• Review the information in Plan the install.
• Install the required tools.
• Download asmcli.
• Grant cluster admin permissions.
• Validate project and cluster.

Warning: For Cloud Service Mesh to function correctly, deploy istiod and canonical-service-controller-manager to your cluster. These tools have elevated role-based access control (RBAC) permissions, such as the ability to modify all deployments and to modify all cluster secrets. These permissions are required for Cloud Service Mesh functions such as injecting sidecars, discovering services, securing traffic, managing ingress gateways, and presenting services dashboards.

Note: If you need to install Cloud Service Mesh from a private or custom container registry, see Use a custom overlay for custom registry.

Roles required to install in-cluster Cloud Service Mesh

The following table describes the roles that are required to install in-cluster Cloud Service Mesh.

Role name	Role ID	Grant location	Description
GKE Hub Admin	roles/gkehub.admin	Fleet project	Full access to GKE Hubs and related resources.
Kubernetes Engine Admin	roles/container.admin	Cluster project. Note that this role must be granted in both Fleet and cluster project for cross-project bindings.	Provides access to full management of Container Clusters and their Kubernetes API objects.
Mesh Config Admin	roles/meshconfig.admin	Fleet and cluster project	Provides permissions required to initialize managed components of Cloud Service Mesh, such as managed control plane and backend permission that allows workloads to talk to Stackdriver without each being individually authorized (for both managed and in-cluster control planes).
Project IAM Admin	roles/resourcemanager.projectIamAdmin	Cluster project	Provides permissions to administer IAM policies on projects.
Service Account Admin	roles/iam.serviceAccountAdmin	Fleet project	Authenticate as a service account.
Service Management Admin	roles/servicemanagement.admin	Fleet project	Full control of Google Service Management resources.
Service Usage Admin	roles/serviceusage.serviceUsageAdmin	Fleet project	Ability to enable, disable, and inspect service states, inspect operations, and consume quota and billing for a consumer project.^(Note 1)
CA Service Admin ^Beta	roles/privateca.admin	Fleet project	Full access to all CA Service resources. ^(Note 2)

Notes:

1. Service Usage Admin - This role is necessary as a prerequisite to enable the mesh.googleapis.com API when initially provisioning managed Cloud Service Mesh.
2. CA Service Admin - This role is only required if you are integrating with CA Service.

Install Cloud Service Mesh

Warning: GitOps tools (including Config Sync, Argo CD, Terraform, and Jenkins) may interfere with your Cloud Service Mesh installation, migration, or upgrade processes. For best results, disable your GitOps tools before you install, migrate, or upgrade Cloud Service Mesh.

The following outlines how to install Cloud Service Mesh:

1. Run asmcli install to install the in-cluster control plane on a single cluster. See the following sections for command line examples. The examples contain both required arguments and optional arguments that you might find useful. We recommend that you always specify the output_dir argument so that you can locate sample gateways and tools such as istioctl. See the navigation bar on the right for a list of the examples.

2. Private GKE clusters need an additional firewall configuration step to allow traffic to istiod.

3. Optionally, install an ingress gateway. By default, asmcli doesn't install the istio-ingressgateway. We recommend that you deploy and manage the control plane and gateways separately. If you need the default istio-ingressgateway installed with the in-cluster control plane, include the --option legacy-default-ingressgateway argument.

4. To complete setting up Cloud Service Mesh, you need to enable automatic sidecar injection and deploy or redeploy workloads.

5. If you are installing Cloud Service Mesh on more than one cluster, run asmcli install on each cluster. When you run asmcli install, be sure to use the same FLEET_PROJECT_ID for each cluster. After Cloud Service Mesh is installed, see the instructions to set up a multi-cluster mesh on GKE.

6. If your clusters are on different networks (as they are in island mode then you should pass a unique network name to asmcli using the --network_id flag.

Install default features and Mesh CA

This section shows how to run asmcli to install Cloud Service Mesh with the default supported features for your platform and enable Cloud Service Mesh certificate authority as the certificate authority.

Run the following command to install the control plane with default features and Cloud Service Mesh certificate authority. Enter your values in the provided placeholders.

./asmcli install \
   --project_id PROJECT_ID \
   --cluster_name CLUSTER_NAME \
   --cluster_location CLUSTER_LOCATION \
   --fleet_id FLEET_PROJECT_ID \
   --output_dir DIR_PATH \
   --enable_all \
   --ca mesh_ca

• --project_id, --cluster_name, and --cluster_location Specify the project ID that the cluster is in, the cluster name, and either the cluster zone or region.
• --fleet_id The project ID of the fleet host project. If you don't include this option, asmcli uses the project that the cluster was created in when registering the cluster.
• --output_dir Include this option to specify a directory where asmcli downloads the anthos-service-mesh package and extracts the installation file, which contains istioctl, samples, and manifests. Otherwise asmcli downloads the files to a tmp directory. You can specify either a relative path or a full path. The environment variable $PWD doesn't work here.
  Note: Make note of this --output_dir directory. You will need to reference it when deploying gateways.
• --enable_all Allows the script to:
  • Grant required IAM permissions.
  • Enable the required Google APIs.
  • Set a label on the cluster that identifies the mesh.
  • Register the cluster to the fleet if it isn't already registered.
• --ca mesh_ca Use Cloud Service Mesh certificate authority as the certificate authority. asmcliconfigures Cloud Service Mesh certificate authority to use fleet workload identity

Install default features and Certificate Authority (CA) Service

This section shows how to run asmcli to install Cloud Service Mesh with the default supported features for your platform and enable CA Service as the certificate authority.

Platform note: CA Service is only supported on the following platforms: GKE clusters on Google Cloud, Google Distributed Cloud (software only) for VMware, and Distributed Cloud. If you run asmcli install and specify --ca gcp_cas on other platforms, the installation appears successful, but your workloads will fail to start.

In addition to Cloud Service Mesh certificate authority, you can configure Cloud Service Mesh to use Certificate Authority Service. This guide provides you an opportunity to integrate with CA Service, which is recommended for the following use cases:

• If you need different certificate authorities to sign workload certificates on different clusters.
• If you need to back your signing keys in a managed HSM.
• If you are in a highly regulated industry and are subject to compliance.
• If you want to chain up your Cloud Service Mesh CA to a custom enterprise root certificate to sign workload certificates.

The cost of Cloud Service Mesh certificate authority is included in the Cloud Service Mesh pricing. The CA Service isn't included in the base Cloud Service Mesh price and is charged separately. Additionally, CA Service comes with an explicit SLA, but the Cloud Service Mesh certificate authority does not.

Configure CA Service

1. Create the CA pool in the tier DevOps and in the same region as the cluster that it serves to avoid excessive latency issues or potential cross-region outages. For more information, see Workload-optimized tiers.
2. Create the CA to have at least one active certificate authority in the CA pool in the same project as the GKE cluster. Use subordinate CA's to sign Cloud Service Mesh workload certificates. Note down the CA pool corresponding to the subordinate CA.

3. If it is meant to only service certificates for Cloud Service Mesh workloads, set up the following issuance policy for the CA pool:

   policy.yaml

   baselineValues:
     keyUsage:
       baseKeyUsage:
         digitalSignature: true
         keyEncipherment: true
       extendedKeyUsage:
         serverAuth: true
         clientAuth: true
     caOptions:
       isCa: false
   identityConstraints:
     allowSubjectPassthrough: false
     allowSubjectAltNamesPassthrough: true
     celExpression:
       expression: subject_alt_names.all(san, san.type == URI && san.value.startsWith("spiffe://PROJECT_ID.svc.id.goog/ns/") )
   

   Note: As a best practice for multi-cluster meshes, set one subordinate CA pool per unique cluster region. All the subordinate CA pools should chain to the same root CA pool.

4. To update the CA pool's issuance policy, use the following command:

   gcloud privateca pools update CA_POOL --location ca_region --issuance-policy policy.yaml
   

   For information on setting a policy on a pool, see Using a certificate issuance policy.

5. If you are using a certificate template, then configure it now. For more information, follow the CA Service guide for workload identity certificates. Ensure the certificate template is created in the same region as the CA pool. If there are multiple regions for CA pools, then create a certificate template per region.

Configure Cloud Service Mesh to use CA Service

Run the following commands on Google Distributed Cloud (software only) for VMware or Google Distributed Cloud (software only) for bare metal to install the control plane with default features and Certificate Authority Service. Enter your values in the provided placeholders.

1. Set the current context to your user cluster:

   kubectl config use-context CLUSTER_NAME
   

2. Run asmcli install:

   ./asmcli install \
     --kubeconfig KUBECONFIG_FILE \
     --fleet_id FLEET_PROJECT_ID \
     --output_dir DIR_PATH \
     --enable_all \
     --ca gcp_cas \
     --platform multicloud \
     --ca_pool  projects/CA_POOL_PROJECT_ID/locations/ca_region/caPools/CA_POOL
   

   • --fleet_id The project ID of the fleet host project.
   • --kubeconfig The full path to the kubeconfig file. The environment variable $PWD doesn't work here. Additionally, relative kubeconfig file locations that use a `~` will not work.
   • --output_dir Include this option to specify a directory where asmcli downloads the anthos-service-mesh package and extracts the installation file, which contains istioctl, samples, and manifests. Otherwise asmcli downloads the files to a tmp directory. You can specify either a relative path or a full path. The environment variable $PWD doesn't work here.
   • --platform multicloud Specifies that the platform is something other than Google Cloud, such as on-premises or multi-cloud.
   • --enable_all Allows the script to:
     • Grant required IAM permissions.
     • Enable the required Google APIs.
     • Set a label on the cluster that identifies the mesh.
     • Register the cluster to the fleet if it isn't already registered.
   • --ca gcp_cas Use Certificate Authority Service as the certificate authority. Changing certificate authorities during an upgrade causes downtime. asmcliconfigures Certificate Authority Service to use fleet workload identity
   • --ca_pool The full identifier for the Certificate Authority Service CA Pool. If you are using a certificate template, then append the template id separated by :. For example:

       --ca_pool projects/CA_POOL_PROJECT_ID/locations/ca_region/caPools/CA_POOL:projects/CA_POOL_PROJECT_ID/locations/ca_region/certificateTemplates/CERT_TEMPLATE_ID
       

   To view SLOs and infrastructure metrics in the Cloud Service Mesh UI, you must also perform the first three steps in Enable application logging and monitoring. If logging and monitoring are not enabled and do not receive custom logs and metrics, the Cloud Service Mesh dashboard will not display SLOs, error logs, or CPU and memory metrics.

Install default features with Istio CA

This section explains how to:

• Generate certificates and keys for the Istio CA that Cloud Service Mesh uses to sign your workloads.
• Run asmcli to install Cloud Service Mesh with default features and enable Istio CA.

By default environments that install Cloud Service Mesh with Istio CA report metrics to Prometheus. If you want to use the Cloud Service Mesh dashboards, you must enable Stackdriver. For more information, see Install with optional features.

For the best security, we highly recommend maintaining an offline root CA and using the subordinate CAs to issue certificates for each cluster. For more information, see Plug in CA Certificates. In this configuration, all workloads in the service mesh use the same root certificate authority (CA). Each Cloud Service Mesh CA uses an intermediate CA signing key and certificate, signed by the root CA. When multiple CAs exist within a mesh, this establishes a hierarchy of trust among the CAs. You can repeat these steps to provision certificates and keys for any number of certificate authorities.

Important: These steps create certificates and keys using a make command that we provide for illustrative purposes only. For the best security, use an offline secure computer and production-ready tools, for example using HashiCorp Vault to securely generate and protect the CA signing key.

The Makefile to generate the certificates is located in the istio-1.23.4-asm.1 subdirectory in the --output_dir directory that you specified in the asmcli validate command. If you didn't run asmcli validate, or you don't have the downloaded directory locally, you can get the Makefile by downloading the Cloud Service Mesh installation file and extracting the contents.

1. Change to the istio-1.23.4-asm.1 directory.

2. Create a directory for the certificates and keys:

   mkdir -p certs && \
   pushd certs

3. Generate a root certificate and key:

   make -f ../tools/certs/Makefile.selfsigned.mk root-ca
   

   This generates these files:

   • root-cert.pem: the root certificate
   • root-key.pem: the root key
   • root-ca.conf: the configuration for openssl to generate the root certificate
   • root-cert.csr: the CSR for the root certificate

4. Generate an intermediate certificate and key:

   make -f ../tools/certs/Makefile.selfsigned.mk cluster1-cacerts

   This generates these files in a directory named cluster1:

   • ca-cert.pem: the intermediate certificates
   • ca-key.pem: the intermediate key
   • cert-chain.pem: the certificate chain which istiod uses
   • root-cert.pem: the root certificate
   Note: You can replace cluster1 with a different name. For example, make mycluster-cacerts creates a directory named mycluster.

   If you perform these steps using an offline computer, copy the generated directory to a computer with access to the clusters.

5. Return to the previous directory:

   popd

6. Run the following command to install the control plane with default features and Istio CA. Enter your values in the provided placeholders.

./asmcli install \
   --project_id PROJECT_ID \
   --cluster_name CLUSTER_NAME \
   --cluster_location CLUSTER_LOCATION \
   --fleet_id FLEET_PROJECT_ID \
   --output_dir DIR_PATH \
   --enable_all \
   --ca citadel \
   --ca_cert CA_CERT_FILE_PATH \
   --ca_key CA_KEY_FILE_PATH \
   --root_cert ROOT_CERT_FILE_PATH \
   --cert_chain CERT_CHAIN_FILE_PATH

• --project_id, --cluster_name, and --cluster_location Specify the project ID that the cluster is in, the cluster name, and either the cluster zone or region.
• --fleet_id The project ID of the fleet host project. If you don't include this option, asmcli uses the project that the cluster was created in when registering the cluster.
• --output_dir Include this option to specify a directory where asmcli downloads the anthos-service-mesh package and extracts the installation file, which contains istioctl, samples, and manifests. Otherwise asmcli downloads the files to a tmp directory. You can specify either a relative path or a full path. The environment variable $PWD doesn't work here.
  Note: Make note of this --output_dir directory. You will need to reference it when deploying gateways.
• --enable_all Allows the script to:
  • Grant required IAM permissions.
  • Enable the required Google APIs.
  • Set a label on the cluster that identifies the mesh.
  • Register the cluster to the fleet if it isn't already registered.
• -ca citadel Use Istio CA as the certificate authority.
• --ca_cert The intermediate certificate
• --ca_key The key for the intermediate certificate
• --root_cert The root certificate
• --cert_chain The certificate chain

Install with Istio CA with Google Cloud Observability enabled

If you want to use Cloud Service Mesh dashboards, you must enable Stackdriver.

Run the following command to install the control plane with default features and Istio CA. Enter your values in the provided placeholders.

./asmcli install \
   --project_id PROJECT_ID \
   --cluster_name CLUSTER_NAME \
   --cluster_location CLUSTER_LOCATION \
   --fleet_id FLEET_PROJECT_ID \
   --output_dir DIR_PATH \
   --enable_all \
   --ca citadel \
   --ca_cert CA_CERT_FILE_PATH \
   --ca_key CA_KEY_FILE_PATH \
   --root_cert ROOT_CERT_FILE_PATH \
   --cert_chain CERT_CHAIN_FILE_PATH

• --project_id, --cluster_name, and --cluster_location Specify the project ID that the cluster is in, the cluster name, and either the cluster zone or region.
• --fleet_id The project ID of the fleet host project. If you don't include this option, asmcli uses the project that the cluster was created in when registering the cluster.
• --output_dir Include this option to specify a directory where asmcli downloads the anthos-service-mesh package and extracts the installation file, which contains istioctl, samples, and manifests. Otherwise asmcli downloads the files to a tmp directory. You can specify either a relative path or a full path. The environment variable $PWD doesn't work here.
  Note: Make note of this --output_dir directory. You will need to reference it when deploying gateways.
• --enable_all Allows the script to:
  • Grant required IAM permissions.
  • Enable the required Google APIs.
  • Set a label on the cluster that identifies the mesh.
  • Register the cluster to the fleet if it isn't already registered.
• -ca citadel Use Istio CA as the certificate authority.
• --ca_cert The intermediate certificate
• --ca_key The key for the intermediate certificate
• --root_cert The root certificate
• --cert_chain The certificate chain
• --option stackdriver Enables Stackdriver option. Note that you can also enable both Stackdriver and Prometheus by using --option prometheus-and-stackdriver.

Install with optional features

An overlay file is a YAML file containing an IstioOperator custom resource (CR) that you pass to asmcli to configure the control plane. You can override the default control plane configuration and enable an optional feature by passing the YAML file to asmcli. You can layer on more overlays, and each overlay file overrides the configuration on the previous layers. As a best practice, we recommend that you save the overlay files in your version control system.

There are two options to enable optional features: --option and --custom_overlay.

Use --option to if you don't need to change the overlay file. With this method asmclifetches the file from the GitHub repository for you.

Use --custom_overlay when you need to customize the overlay file.

For more information, see Enabling optional features on the in-cluster control plane.

Run the following command to install the control plane with an optional feature. To add multiple files, specify --custom_overlay and the filename, for example: --custom_overlay overlay_file1.yaml --custom_overlay overlay_file2.yaml --custom_overlay overlay_file3.yaml Enter your values in the provided placeholders.

./asmcli install \
--project_id PROJECT_ID \
--cluster_name CLUSTER_NAME \
--cluster_location CLUSTER_LOCATION \
--fleet_id FLEET_PROJECT_ID \
--output_dir DIR_PATH \
--enable_all \
--ca mesh_ca \
--custom_overlay OVERLAY_FILE

• --project_id, --cluster_name, and --cluster_location Specify the project ID that the cluster is in, the cluster name, and either the cluster zone or region.
• --fleet_id The project ID of the fleet host project. If you don't include this option, asmcli uses the project that the cluster was created in when registering the cluster.
• --output_dir Include this option to specify a directory where asmcli downloads the anthos-service-mesh package and extracts the installation file, which contains istioctl, samples, and manifests. Otherwise asmcli downloads the files to a tmp directory. You can specify either a relative path or a full path. The environment variable $PWD doesn't work here.
  Note: Make note of this --output_dir directory. You will need to reference it when deploying gateways.
• --enable_all Allows the script to:
  • Grant required IAM permissions.
  • Enable the required Google APIs.
  • Set a label on the cluster that identifies the mesh.
  • Register the cluster to the fleet if it isn't already registered.
• --ca mesh_ca Use Cloud Service Mesh certificate authority as the certificate authority. Note that asmcliconfigures Cloud Service Mesh certificate authority to use fleet workload identity
• --custom_overlay Specify the name of the overlay file.

Install gateways

Cloud Service Mesh gives you the option to deploy and manage gateways as part of your service mesh. A gateway describes a load balancer operating at the edge of the mesh receiving incoming or outgoing HTTP/TCP connections. Gateways are Envoy proxies that provide you with fine-grained control over traffic entering and leaving the mesh.

1. Create a namespace for the ingress gateway if you don't already have one. Gateways are user workloads, and as a best practice, they shouldn't be deployed in the control plane namespace. Replace GATEWAY_NAMESPACE with the name of your namespace.

   kubectl create namespace GATEWAY_NAMESPACE
   

   Expected output:

   namespace/GATEWAY_NAMESPACE created
   

2. Enable auto-injection on the gateway. The steps required depend on whether you want to use default injection labels (for example, istio-injection=enabled) or the revision label on the gateway namespace. The default revision tag and revision label are used by the sidecar injector webhook to associate injected proxies with a particular control plane revision.

   Default injection labels

   Note: If you used a default tag revision to enable auto-injection on the gateway then verify the default tag exists in the directory that you specified in --output_dir and is pointing to the newly installed revision. Run the command istioctl tag list.

   Apply the default injection labels to the namespace.

   kubectl label namespace GATEWAY_NAMESPACE istio-injection=enabled istio.io/rev-
   

   Revision label

   1. Use the following command to locate the revision label on istiod:

      kubectl get deploy -n istio-system -l app=istiod -o \
        "jsonpath={.items[*].metadata.labels['istio\.io/rev']}{'\n'}"
      

      The command outputs the revision label that corresponds to the Cloud Service Mesh version, for example: asm-1234-1

   2. Apply the revision label to the namespace. In the following command, REVISION is the value of the istiod revision label that you noted in the previous step.

      kubectl label namespace GATEWAY_NAMESPACE \
        istio.io/rev=REVISION --overwrite
      

      Expected output:

      namespace/GATEWAY_NAMESPACE labeled
      

   You can ignore the message "istio.io/rev" not found in the output. That means that the namespace didn't previously have the istio.io/rev label, which you should expect in new installations of Cloud Service Mesh or new deployments. Because auto-injection fails if a namespace has both the istio.io/rev and the istio-injection label, all kubectl label commands in the Cloud Service Mesh documentation explicitly specify both labels.

   If the gateway namespace is not labelled, the istio-ingressgateway pods will fail with an ImagePullBackOff error when the gateway attempts to pull and the auto image. This image should be replaced by the webhook.

3. Download the example ingress gateway .yaml configuration file from the anthos-service-mesh-packages repository.

4. Apply the example ingress gateway .yaml configuration as is, or modify as needed.

   kubectl apply -n GATEWAY_NAMESPACE \
     -f CONFIG_PATH/istio-ingressgateway
   

   Expected output:

   deployment.apps/istio-ingressgateway created
   poddisruptionbudget.policy/istio-ingressgateway created
   horizontalpodautoscaler.autoscaling/istio-ingressgateway created
   role.rbac.authorization.k8s.io/istio-ingressgateway created
   rolebinding.rbac.authorization.k8s.io/istio-ingressgateway created
   service/istio-ingressgateway created
   serviceaccount/istio-ingressgateway created
   

Learn more about best practices for gateways.

Deploy and redeploy workloads

Warning: If you are installing sidecars in application pods where CA connectivity through a direct connection is not available (for example, due to firewalls or other restrictive features), then you must Configure CA connectivity through a proxy after installing the in-cluster control plane and before redeploying workloads.

Cloud Service Mesh uses sidecar proxies to enhance network security, reliability, and observability. With Cloud Service Mesh, these functions are abstracted away from the application's primary container and implemented in a common out-of-process proxy delivered as a separate container in the same Pod.

Your installation isn't complete until you enable automatic sidecar proxy injection (auto-injection) and restart the Pods for any workloads that were running on your cluster before you installed Cloud Service Mesh.

To enable auto-injection, you label your namespaces with the default injection labels if the default tag is set up, or a revision label that was set on istiod when you installed Cloud Service Mesh. The default revision tag and revision label are used by the sidecar injector webhook to associate injected sidecars with an istiod revision. After adding the label, any existing Pods in the namespace must be restarted for sidecars to be injected.

Before you deploy new workloads in a new namespace, make sure to configure auto-injection so that Cloud Service Mesh can monitor and secure traffic.

1. The steps required to enable auto-injection depend on whether you want to use default injection labels or the revision label:

   Default (Recommended)

   1. If you used a default tag revision to enable auto-injection on the gateway, verify that the default tag exists in the directory that you specified in --output_dir and that it is pointing to the newly installed revision.

      DIR_PATH/istioctl tag list
      

   2. Run the following command. NAMESPACE is the name of the namespace where you want to enable auto-injection.

      kubectl label namespace NAMESPACE istio-injection=enabled istio.io/rev-
      

   The default injection labels inject the revision the default tag is pointing to.

   Revision label

   1. Use the following command to locate the revision label on istiod:

      kubectl -n istio-system get pods -l app=istiod --show-labels
      

      The output looks similar to the following:

      NAME                                READY   STATUS    RESTARTS   AGE   LABELS
      istiod-asm-1234-1-5788d57586-bljj4   1/1     Running   0          23h   app=istiod,istio.io/rev=asm-1234-1,istio=istiod,pod-template-hash=5788d57586
      istiod-asm-1234-1-5788d57586-vsklm   1/1     Running   1          23h   app=istiod,istio.io/rev=asm-1234-1,istio=istiod,pod-template-hash=5788d57586

      In the output, under the LABELS column, note the value of the istiod revision label, which follows the prefix istio.io/rev=. In this example, the value is asm-1234-1.

   2. Apply the revision label and remove the istio-injection label if it exists. In the following command, NAMESPACE is the name of the namespace where you want to enable auto-injection, and REVISION is the revision label you noted in the previous step.

      kubectl label namespace NAMESPACE istio-injection- istio.io/rev=REVISION --overwrite
      

      You can ignore the message "istio-injection not found" in the output. That means that the namespace didn't previously have the istio-injection label, which you should expect in new installations of Cloud Service Mesh or new deployments. Because auto-injection behavior is undefined when a namespace has both the istio-injection and the revision label, all kubectl label commands in the Cloud Service Mesh documentation explicitly ensure that only one is set.

2. If workloads were running on your cluster before you installed Cloud Service Mesh, restart the Pods to trigger re-injection.

   How you restart Pods depends on your application and the environment the cluster is in. For example, in your staging environment, you might simply delete all the Pods, which causes them to restart. But in your production environment, you might have a process that implements a blue-green deployment so that you can safely restart Pods to avoid traffic interruption.

   You can use kubectl to perform a rolling restart:

   kubectl rollout restart deployment -n NAMESPACE
   

What's next?

• If your mesh consists entirely of GKE clusters, see Set up a multi-cluster mesh on GKE.

• Configure an external IP address on-premises.

• Deploy the Online Boutique sample application.