Customizable Install with Istioctl

Follow this guide to install and configure an Istio mesh for in-depth evaluation or production use. If you are new to Istio, and just want to try it out, follow the quick start instructions instead.

This installation guide uses the istioctl command line tool to provide rich customization of the Istio control plane and of the sidecars for the Istio data plane. It has user input validation to help prevent installation errors and customization options to override any aspect of the configuration.

Using these instructions, you can select any one of Istio’s built-in configuration profiles and then further customize the configuration for your specific needs.

Prerequisites

Before you begin, check the following prerequisites:

1. Download the Istio release.
2. Perform any necessary platform-specific setup.
3. Check the Requirements for Pods and Services.

Install Istio using the default profile

The simplest option is to install the default Istio configuration profile using the following command:

$ istioctl manifest apply

This command installs the default profile on the cluster defined by your Kubernetes configuration. The default profile is a good starting point for establishing a production environment, unlike the larger demo profile that is intended for evaluating a broad set of Istio features.

If you want to enable security on top of the default profile, you can set the security related configuration parameters:

$ istioctl manifest apply --set values.global.mtls.enabled=true

In general, you can use the --set flag in istioctl as you would with Helm. The only difference is you must prefix the setting paths with values. because this is the path to the Helm pass-through API, described below.

Install from external charts

By default, istioctl uses compiled-in charts to generate the install manifest. These charts are released together with istioctl for auditing and customization purposes and can be found in the release tar in the install/kubernetes/operator/charts directory. istioctl can also use external charts rather than the compiled-in ones. To select external charts, set installPackagePath to a local file system path:

$ istioctl manifest apply --set installPackagePath=~/istio-releases/istio-1.5.4/install/kubernetes/operator/charts

If using the istioctl 1.5.4 binary, this command will result in the same installation as istioctl manifest apply alone, because it points to the same charts as the compiled-in ones. Other than for experimenting with or testing new features, we recommend using the compiled-in charts rather than external ones to ensure compatibility of the istioctl binary with the charts.

Install a different profile

Other Istio configuration profiles can be installed in a cluster by passing the profile name on the command line. For example, the following command can be used to install the demo profile:

$ istioctl manifest apply --set profile=demo

Display the list of available profiles

You can display the names of Istio configuration profiles that are accessible to istioctl by using this command:

$ istioctl profile list
Istio configuration profiles:
    minimal
    remote
    sds
    default
    demo

Display the configuration of a profile

You can view the configuration settings of a profile. For example, to view the setting for the demo profile run the following command:

$ istioctl profile dump demo
autoInjection:
  components:
    injector:
      enabled: true
      k8s:
        replicaCount: 1
        strategy:
          rollingUpdate:
            maxSurge: 100%
            maxUnavailable: 25%
  enabled: true
cni:
  components:
    cni:
      enabled: false
  enabled: false
...

To view a subset of the entire configuration, you can use the --config-path flag, which selects only the portion of the configuration under the given path:

$ istioctl profile dump --config-path trafficManagement.components.pilot demo
enabled: true
k8s:
  env:
  - name: POD_NAME
    valueFrom:
      fieldRef:
        apiVersion: v1
        fieldPath: metadata.name
  - name: POD_NAMESPACE
    valueFrom:
      fieldRef:
        apiVersion: v1
        fieldPath: metadata.namespace
  - name: GODEBUG
    value: gctrace=1
  - name: PILOT_TRACE_SAMPLING
    value: "100"
  - name: CONFIG_NAMESPACE
    value: istio-config
  hpaSpec:
    maxReplicas: 5
    metrics:
...

Show differences in profiles

The profile diff sub-command can be used to show the differences between profiles, which is useful for checking the effects of customizations before applying changes to a cluster.

You can show differences between the default and demo profiles using these commands:

$ istioctl profile diff <(istioctl profile dump default) <(istioctl profile dump demo)
 gateways:
   components:
     egressGateway:
-      enabled: false
+      enabled: true
...
           requests:
-            cpu: 100m
-            memory: 128Mi
+            cpu: 10m
+            memory: 40Mi
         strategy:
...

Generate a manifest before installation

You can generate the manifest before installing Istio using the manifest generate sub-command, instead of manifest apply. For example, use the following command to generate a manifest for the default profile:

$ istioctl manifest generate > $HOME/generated-manifest.yaml

Inspect the manifest as needed, then apply the manifest using this command:

$ kubectl apply -f $HOME/generated-manifest.yaml

Show differences in manifests

You can show the differences in the generated manifests in a YAML style diff between the default profile and a customized install using these commands:

$ istioctl manifest generate > 1.yaml
$ istioctl manifest generate -f samples/operator/pilot-k8s.yaml > 2.yaml
$ istioctl manifest diff 1.yam1 2.yaml
Differences of manifests are:

Object Deployment:istio-system:istio-pilot has diffs:

spec:
  template:
    spec:
      containers:
        '[0]':
          resources:
            requests:
              cpu: 500m -> 1000m
              memory: 2048Mi -> 4096Mi
      nodeSelector: -> map[master:true]
      tolerations: -> [map[effect:NoSchedule key:dedicated operator:Exists] map[key:CriticalAddonsOnly
        operator:Exists]]


Object HorizontalPodAutoscaler:istio-system:istio-pilot has diffs:

spec:
  maxReplicas: 5 -> 10
  minReplicas: 1 -> 2

Verify a successful installation

You can check if the Istio installation succeeded using the verify-install command which compares the installation on your cluster to a manifest you specify.

If you didn’t generate your manifest prior to deployment, run the following command to generate it now:

$ istioctl manifest generate <your original installation options> > $HOME/generated-manifest.yaml

Then run the following verify-install command to see if the installation was successful:

$ istioctl verify-install -f $HOME/generated-manifest.yaml

Customizing the configuration

In addition to installing any of Istio’s built-in configuration profiles, istioctl manifest provides a complete API for customizing the configuration.

• The IstioControlPlane API

The configuration parameters in this API can be set individually using --set options on the command line. For example, to enable the security feature in a default configuration profile, use this command:

$ istioctl manifest apply --set values.global.mtls.enabled=true

Alternatively, the IstioControlPlane configuration can be specified in a YAML file and passed to istioctl using the -f option:

$ istioctl manifest apply -f samples/operator/pilot-k8s.yaml

Identify an Istio feature or component

The IstioControlPlane API groups control plane components by feature, as shown in the table below:

In addition to the core Istio components, third-party addon features and components are also available. These can only be enabled and configured through the Helm pass-through API:

Features can be enabled or disabled, which enables or disables all of the components that are a part of the feature. Namespaces that components are installed into can be set by component, feature, or globally.

Configure the feature or component settings

After you identify the name of the feature or component from the previous table, you can use the API to set the values using the --set flag, or create an overlay file and use the --filename flag. The --set flag works well for customizing a few parameters. Overlay files are designed for more extensive customization, or tracking configuration changes.

The simplest customization is to turn a feature or component on or off from the configuration profile default.

To disable the telemetry feature in a default configuration profile, use this command:

$ istioctl manifest apply --set telemetry.enabled=false

Alternatively, you can disable the telemetry feature using a configuration overlay file:

1. Create this file with the name telemetry_off.yaml and these contents:

apiVersion: install.istio.io/v1alpha2
kind: IstioControlPlane
spec:
  telemetry:
    enabled: false

1. Use the telemetry_off.yaml overlay file with the manifest apply command:

$ istioctl manifest apply -f telemetry_off.yaml

You can also use this approach to set the component-level configuration, such as enabling the node agent:

$ istioctl manifest apply --set security.components.nodeAgent.enabled=true

Another customization is to select different namespaces for features and components. The following is an example of installation namespace customization:

apiVersion: install.istio.io/v1alpha2
kind: IstioControlPlane
spec:
  defaultNamespace: istio-system
  security:
    namespace: istio-security
    components:
      citadel:
        namespace: istio-citadel

Applying this file will cause the default profile to be applied, with components being installed into the following namespaces:

• The Citadel component is installed into istio-citadel namespace
• All other components in the security feature installed into istio-security namespace
• Remaining Istio components installed into istio-system namespace

Customize Kubernetes settings

The IstioControlPlane API allows each component’s Kubernetes settings to be customized in a consistent way.

Each component has a KubernetesResourceSpec, which allows the following settings to be changed. Use this list to identify the setting to customize:

1. Resources
2. Readiness probes
3. Replica count
4. HorizontalPodAutoscaler
5. PodDisruptionBudget
6. Pod annotations
7. Service annotations
8. ImagePullPolicy
9. Priority class name
10. Node selector
11. Affinity and anti-affinity

All of these Kubernetes settings use the Kubernetes API definitions, so Kubernetes documentation can be used for reference.

The following example overlay file adjusts the TrafficManagement feature’s resources and horizontal pod autoscaling settings for Pilot:

apiVersion: install.istio.io/v1alpha2
kind: IstioControlPlane
spec:
  trafficManagement:
    components:
      pilot:
        k8s:
          resources:
            requests:
              cpu: 1000m # override from default 500m
              memory: 4096Mi # ... default 2048Mi
          hpaSpec:
            maxReplicas: 10 # ... default 5
            minReplicas: 2  # ... default 1
          nodeSelector:
            master: "true"
          tolerations:
          - key: dedicated
            operator: Exists
            effect: NoSchedule
          - key: CriticalAddonsOnly
            operator: Exists

Use manifest apply to apply the modified settings to the cluster:

$ istioctl manifest apply -f samples/operator/pilot-k8s.yaml

Customize Istio settings using the Helm API

The IstioControlPlane API includes a pass-through interface to the Helm API using the values field.

The following YAML file configures global and Pilot settings through the Helm API:

apiVersion: install.istio.io/v1alpha2
kind: IstioControlPlane
spec:
  trafficManagement:
    components:
      pilot:
        values:
          traceSampling: 0.1 # override from 1.0

  # global Helm settings
  values:
    global:
      monitoringPort: 15050

Some parameters will temporarily exist in both the Helm and IstioControlPlane APIs, including Kubernetes resources, namespaces and enablement settings. The Istio community recommends using the IstioControlPlane API as it is more consistent, is validated, and follows the community graduation process.

Uninstall Istio

To uninstall Istio, run the following command:

$ istioctl manifest generate <your original installation options> | kubectl delete -f -