Enable optional features on an in-cluster control plane

This page describes how to enable optional features on Cloud Service Mesh with an in-cluster control plane.

When you install in-cluster Cloud Service Mesh, the features that are enabled by default differ by platform. You can override the default configuration and enable an optional feature by including an overlay file when you install (or upgrade) Cloud Service Mesh. An overlay file is a YAML file containing an IstioOperator custom resource (CR) that you use to configure the control plane. Specify one feature per overlay file. You can layer on more overlays, and each overlay file overrides the configuration on the previous layers.

Caution: Using asmcli install overwrites the existing control plane configuration. When you enable optional features to an existing installation, make sure to specify all files that you want to keep in the original configuration, as well as the overlay files for the features that you want to enable. We recommended that you store the overlay files that you use for installation in source control so that you can apply the same configurations to your control plane with upgrades or when enabling additional optional features. This ensures no downtime when enabling optional features.

About the overlay files

The overlay files on this page are in the anthos-service-mesh package in GitHub. These files contain common customizations to the default configuration. You can use these files as they are, or you can make additional changes to them as needed.

When you install Cloud Service Mesh using asmcli script, you can specify one or more overlay files with the --option or the --custom_overlay options. If you don't need to make any changes to the files in the anthos-service-mesh repository, you can use --option, and the script fetches the file from GitHub for you. Otherwise, you can make changes to the overlay file, and then use the --custom_overlay option to pass it to the asmcli.

Important: Don't specify more than one IstioOperator CR in an overlay file because istioctl install only applies the first CR that it finds in the file.

Don't include multiple CRs in one overlay file	Create separate overlay files for each CR

How to enable optional features

The following examples are simplified to show only using the custom overlays to enable optional features. Replace OTHER_FLAGS with the required installation flags.

Important: The order of the files on the command line matters. Be sure to specify the configuration required for the default features first, and then the overlay files after that.

The asmcli install command provides two ways to enable an optional feature. The method that you use depends on whether you need to make changes to the overlay file.

• Use --option when you don't need to make any changes to the overlay file. With --option, asmcli fetches the file from the GitHub repository for you, so you must have an internet connection.

  ./asmcli install \
    OTHER_FLAGS \
    --option OPTION_NAME
  

  Replace OPTION_NAME with the option you want to enable. Be sure to omit the .yaml extension and only include the name of the overlay file, such as iap-operator and attached-cluster. For a list of options refer to the anthos-service-mesh package.

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

  ./asmcli install \
    OTHER_FLAGS \
    --custom_overlay PATH_TO_FILE
  

  Replace PATH_TO_FILE with the path to the overlay file you want to use.

YAML for optional features

The following sections provide the YAML to enable optional and supported features.

mTLS STRICT mode

The global.mtls.enabled configuration was removed from the IstioOperator CR to avoid issues with upgrades and to provide a more flexible installation. To enable STRICT mTLS, configure a peer authentication policy instead.

Distroless proxy image

As a best practice, you should restrict the contents of a container runtime to only the necessary packages. This approach improves security and the signal-to-noise ratio of Common Vulnerabilities and Exposures (CVE) scanners. Istio provides proxy images based on distroless base images.

The following configuration enables distroless images for the entire Cloud Service Mesh. An image type change requires each pod to restart and get re-injected to take effect.

apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  meshConfig:
    defaultConfig:
      image:
        imageType: distroless

The distroless image does not contain any binaries other than the proxy. It is therefore not possible to exec a shell or use curl, ping, or other debug utilities inside the container.

If you run a curl command, you see the following error:

error: Internal error occurred: error executing command in container: failed to exec in container: failed to start exec  "<container-id>"
OCI runtime exec failed: exec failed: unable to start container process: exec: "curl": executable file not found in $PATH: unknown

If you run a shell command, you see the following error:

error: Internal error occurred: error executing command in container: failed to exec in container: failed to start exec "<container-id>"
OCI runtime exec failed: exec failed: container_linux.go:380: starting container process caused: exec: "sh": executable file not found in $PATH: unknown

If you need access to these tools for specific pods, you may override the imageType by using the following pod annotation.

sidecar.istio.io/proxyImageType: debug

After changing the image type of a deployment via the annotation, the deployment should be restarted.

kubectl rollout restart deployment -n NAMESPACE DEPLOYMENT_NAME

For most types of proxy debugging, istioctl proxy-cmd should be used which does not require a debug base image.

Use a custom overlay for custom registry

You can use a custom overlay for custom registries, such as if you need to install Cloud Service Mesh from a custom container registry. For example:

apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  hub: {private_registry_url}

The following is a list of images for Cloud Service Mesh that you need to mirror to the custom container registry:

• Install-cni - gke.gcr.io/asm/install-cni:1.21.5-asm.12
• Managed Data Plane - gke.gcr.io/asm/mdp:1.21.5-asm.12
• Pilot - gke.gcr.io/asm/pilot:1.21.5-asm.12
• Proxyv2 - gke.gcr.io/asm/proxyv2:1.21.5-asm.12

Note: If you use a Canonical Service, then you also need to mirror the custom container registries gcr.io/kubebuilder/kube-rbac-proxy:v0.13.1 and gke.gcr.io/asm/canonical-service-controller:1.10.3-asm.16.

Add images to a private registry

To push Cloud Service Mesh images to a private registry, complete the following steps.

Note: Use a client from which you can pull from gcr.io and push to your private registry.

1. Pull the Cloud Service Mesh images:

   docker pull gke.gcr.io/asm/install-cni:1.21.5-asm.12
   docker pull gke.gcr.io/asm/mdp:1.21.5-asm.12
   docker pull gke.gcr.io/asm/pilot:1.21.5-asm.12
   docker pull gke.gcr.io/asm/proxyv2:1.21.5-asm.12
   

2. Create a variable for your private registry URL:

   export PRIVATE_REGISTRY_URL=PRIVATE_REGISTRY_URL
   

   Replace PRIVATE_REGISTRY_URL with your private registry URL.
3. Tag the images with your private registry URL:

   docker tag gke.gcr.io/asm/install-cni:1.21.5-asm.12 \
    ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/install-cni:1.21.5-asm.12
   docker tag gke.gcr.io/asm/mdp:1.21.5-asm.12 \
    ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/mdp:1.21.5-asm.12
   docker tag gke.gcr.io/asm/pilot:1.21.5-asm.12 \
    ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/pilot:1.21.5-asm.12
   docker tag gke.gcr.io/asm/proxyv2:1.21.5-asm.12 \
    ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/proxyv2:1.21.5-asm.12
   

4. Push the tagged images to your private registry:

   docker push ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/install-cni:1.21.5-asm.12
   docker push ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/mdp:1.21.5-asm.12
   docker push ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/pilot:1.21.5-asm.12
   docker push ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/proxyv2:1.21.5-asm.12
   

5. (Optional) If you use a canonical service, then add the canonical service images to your private registry.
   1. Pull the Cloud Service Mesh canonical service images:

              docker pull gcr.io/kubebuilder/kube-rbac-proxy:v0.13.1
              docker pull gke.gcr.io/asm/canonical-service-controller:1.10.3-asm.16
              

   2. Tag the images with your private registry URL:

              docker tag gcr.io/kubebuilder/kube-rbac-proxy:v0.13.1 \
              ${PRIVATE_REGISTRY_URL}/gcr.io/kubebuilder/kube-rbac-proxy:v0.13.1
              docker tag gke.gcr.io/asm/canonical-service-controller:1.10.3-asm.16 \
              ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/canonical-service-controller:1.10.3-asm.16
              

   3. Push the tagged images to your private registry:

              docker push ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/kube-rbac-proxy:v0.13.1
              docker push ${PRIVATE_REGISTRY_URL}/gke.gcr.io/asm/canonical-service-controller:1.10.3-asm.16
              

If you can pull the tagged images from your private registry, then the procedure was successful.

Increase termination drain duration

By default Envoy will wait five seconds (5s) for existing connections to complete when a pod is terminating.

Pod terminationGracePeriodSeconds must be greater than terminationDrainDuration value.

For more information see Global Mesh Options.

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  meshConfig:
    defaultConfig:
      terminationDrainDuration: 30s

Enable Access logs

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  meshConfig:
    accessLogFile: "/dev/stdout"

For more information, see Enable Envoy's access logging.

Cloud Trace

Cloud Trace is available with Cloud Service Mesh installations on the following platforms:

• GKE on Google Cloud
• GKE Enterprise clusters on-premises if you install with Cloud Service Mesh certificate authority

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  meshConfig:
    enableTracing: true
  values:
    global:
      proxy:
        tracer: stackdriver

For more information, see Accessing traces.

Egress via egress gateways

We recommend that you install an injected gateway as described in Install and upgrade gateways.

Istio Container Network Interface

How you enable the Istio Container Network Interface (CNI) depends on the environment that Cloud Service Mesh is installed on.

1. Enable a network policy.

2. Choose the overlay file that matches your platform.

Enable CNI on GKE

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  components:
    cni:
      enabled: true
      namespace: kube-system
  values:
    cni:
      cniBinDir: /home/kubernetes/bin
      excludeNamespaces:
        - istio-system
        - kube-system

Enable CNI on-premises

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  components:
    cni:
      enabled: true
      namespace: kube-system
  values:
    cni:
      cniBinDir: /opt/cni/bin
      excludeNamespaces:
        - istio-system
        - kube-system
        - gke-system

Enable Traffic logs for off-Google Cloud

Installing Cloud Service Mesh with Istio CA outside of Google Cloud reports metrics to Prometheus by default. Use this option to enable reporting Traffic logs instead, or both Prometheus and Stackdriver, so you can use the Cloud Service Mesh dashboards.

Only Stackdriver

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  values:
    telemetry:
      enabled: true
      v2:
        enabled: true
        prometheus:
          enabled: false
        stackdriver:
          enabled: true

Stackdriver and Prometheus

---
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  values:
    telemetry:
      enabled: true
      v2:
        enabled: true
        prometheus:
          enabled: true
        stackdriver:
          enabled: true

Enable an internal load balancer

We recommend that you install an injected gateway as described in Install and upgrade gateways to set up an internal load balancer on GKE. When configuring the gateway Service, you include the annotation: networking.gke.io/load-balancer-type: "Internal"

External certificate management on the ingress gateway

For information on enabling external certificate management on the ingress gateway using Envoy SDS, see Secure Gateways.