Version 1.11

Enabling optional features on the in-cluster control plane

This page describes how to enable optional features on an in-cluster control plane. For information on the Google-managed control plane, see Configure managed Anthos Service Mesh.

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

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 Anthos Service Mesh using the Google-provided 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.

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

Downloading the anthos-service-mesh package

To download the anthos-service-mesh package:

The following steps use kpt to download the asm package from the GitHub repository. If you prefer, you can use git clone instead.

  1. Install kpt if you haven't already:

    gcloud components install kpt
    
  2. Download the package that contains the files:

    kpt pkg get \
    https://github.com/GoogleCloudPlatform/anthos-service-mesh-packages.git/asm@release-1.11 asm
    

    The following examples assume that the asm package is in your current working directory.

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 other command line options .

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. 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.

Direct Envoy to stdout

---
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 Anthos Service Mesh installations on the following platforms:

  • GKE on Google Cloud
  • Anthos clusters on-premises if you install with Anthos Service Mesh certificate authority (Mesh CA)

For detailed pricing information, refer to the Cloud Trace pricing page.

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

The default sampling rate is 1%, but you can override the default by specifying a tracing.sampling value. The value must be in the range of 0.0 to 100.0 with a precision of 0.01. For example, to trace 5 requests out of every 10,000, use 0.05.

The following example shows a sampling rate of 100% (which you would only do for demo or troubleshooting purposes).

apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
spec:
  meshConfig:
    enableTracing: true
    defaultConfig:
      tracing:
        sampling: 100
  values:
    global:
      proxy:
        tracer: stackdriver

Note that currently tracer configuration is part of proxy bootstrap configuration, so pod needs to restart and get re-injected to pick up the tracer update. For example, you can use the following command the restart pods belong to a deployment:

kubectl rollout restart deployment -n NAMESPACE DEPLOYMENT_NAME

Trace context propagation

Although the sidecar proxies can automatically send trace spans, they need some hints to tie together the entire trace. Applications need to propagate the appropriate HTTP headers so that when the proxies send span information, the spans can be correlated correctly into a single trace.

To do this, an application needs to collect and propagate the following headers from the incoming request to any outgoing requests:

  • x-request-id
  • x-b3-traceid
  • x-b3-spanid
  • x-b3-parentspanid
  • x-b3-sampled
  • x-b3-flags
  • x-ot-span-context
  • x-cloud-trace-context
  • traceparent
  • grpc-trace-bin

For examples propagating the headers, see Trace context propagation.

Create a trace from client with custom ID

To create a trace from a client with a custom ID, use the curl command to create a request with an external client and force it to show a trace. For example:

curl $URL --header "x-client-trace-id: 105445aa7843bc8bf206b12000100000"

For more information about x-client-trace-id, refer to the Envoy documentation.

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 Anthos 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 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: cloud.google.com/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.