ICA Istio Installation Upgrade And Configuration — 20 Questions

Question 1

You are performing a canary upgrade of the Istio control plane using the revision-based approach. After deploying the new revision, how do you verify which pods are currently pointing to the new control plane?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

kubectl get pods -l istio.io/rev. You verify the configuration by checking the 'istio.io/rev' label on the pods to see which revision they are assigned to.

Answer

istioctl upgrade status

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istioctl proxy-config endpoint

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kubectl describe svc istiod

Question 2

Which 'istioctl' command is used to verify that the current Istio configuration in a cluster is valid and follows best practices?

Accepted Answer

istioctl analyze. The 'istioctl analyze' command inspects the cluster and identifies configuration errors or warnings.

Answer

istioctl check

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istioctl diagnose

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istioctl verify

Question 3

When using IstioOperator to customize the installation, you want to change the number of replicas for the Istiod control plane. Where should this be defined?

Accepted Answer

spec.components.pilot.k8s.replicaCount. The 'spec.components.pilot.k8s.hpaSpec' or 'spec.components.pilot.k8s.replicaCount' fields are the correct places to define scale for the pilot component.

Answer

spec.values.pilot.scaling

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spec.meshConfig.pilot.replicas

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spec.pilot.replicas

Question 4

A team wants to enable sidecar injection for a specific namespace without modifying the deployment manifests. What is the most efficient way to achieve this?

Accepted Answer

kubectl label namespace <name> istio-injection=enabled. Labeling the namespace with 'istio-injection=enabled' triggers the sidecar injector webhook to automatically inject proxies into new pods.

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istioctl inject -n <namespace>

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kubectl apply -f sidecar-injector.yaml

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kubectl annotate namespace <name> istio-injection=enabled

Question 5

You need to add a custom CA certificate to the Istio control plane during installation. How do you pass this using IstioOperator?

Accepted Answer

spec.values.global.certificates.caCertificates. You use the 'spec.values.global.certificates' or specific secret mounts to provide custom certificates to Istiod.

Answer

spec.meshConfig.caCertificates

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spec.components.pilot.k8s.env

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spec.security.ca.path

Question 6

You need to configure the IstioOperator CR to disable mTLS globally for a legacy migration. Which field correctly sets the global peer authentication policy?

Accepted Answer

spec.values.global.mtls.enabled: false. The 'spec.meshConfig.defaultConfig.peerAuthenticationPolicy' is not the correct path; the global mTLS setting is handled via 'spec.values.global.mtls.enabled'.

Answer

spec.components.pilot.mtls: false

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spec.meshConfig.mtls: false

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spec.security.globalMtls: false

Question 7

You are installing Istio for a development cluster and want to use a predefined configuration that includes the core components but disables unnecessary features like telemetry to save resources. Which profile should you choose?

Accepted Answer

minimal. The 'minimal' profile installs only the base resources and the control plane, making it ideal for resource-constrained development environments.

Answer

preview

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demo

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default

Question 8

You are performing an in-place upgrade of Istio. You have updated the control plane, but your data plane proxies are still running the old image. What is the standard process to upgrade the proxies?

Accepted Answer

kubectl rollout restart deployment. To upgrade the data plane proxies, you must perform a rolling restart of the pods to trigger the injector to pull the new sidecar image.

Answer

istioctl upgrade --data-plane

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kubectl patch deployment -p '{"spec":{"template":{"metadata":{"annotations":{"sidecar.istio.io/status":"update"}}}}}'

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istioctl proxy-status --upgrade

Question 9

Which profile is recommended for a production environment where high availability and performance are required?

Accepted Answer

default. The 'default' profile is optimized for production use cases with HA settings enabled.

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minimal

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empty

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demo

Question 10

You have a cluster with multiple revisions of Istio installed. You want to move a namespace from revision '1-18' to '1-19'. What is the correct procedure?

Accepted Answer

Update label and restart pods. You must update the 'istio.io/rev' label on the namespace to the new revision and then perform a rolling restart of the pods in that namespace.

Answer

Use 'istioctl install --revision 1-19' on the namespace

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Update label and run 'istioctl proxy-config rev 1-19'

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Just update the label; Istio handles it automatically

Question 11

You want to exclude a specific container in a pod from being injected with the Istio proxy. How is this achieved?

Accepted Answer

Add annotation 'sidecar.istio.io/inject: "false"' to the pod. You add the annotation 'sidecar.istio.io/inject: "false"' to the pod template or the specific container annotation if supported via sidecar lifecycle hooks.

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Modify the IstioOperator to exclude the container

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Add label 'sidecar.istio.io/skip'

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Add environment variable 'ISTIO_PROXY_IGNORE=true'

Question 12

If you want to use a custom proxy image for your sidecars, where should this be specified in the IstioOperator configuration?

Accepted Answer

spec.values.global.proxy.image. The 'spec.values.global.proxy.image' field is used to override the default image for the sidecar proxies.

Answer

spec.components.proxy.image

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spec.meshConfig.defaultConfig.proxyImage

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spec.sidecarInjector.image

Question 13

When configuring an IstioOperator file, what does the 'spec.meshConfig' section primarily control?

Accepted Answer

Mesh-wide proxy and traffic behavior policies. The 'meshConfig' section defines the mesh-wide configuration options that apply to all proxies in the mesh.

Answer

The version of Istio to install

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The ingress gateway load balancer IP

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Kubernetes deployment manifests for Istiod

Question 14

What is the purpose of the 'istio-sidecar-injector' service in the Istio control plane?

Accepted Answer

To inject the Envoy proxy sidecar into pods. The sidecar injector is a MutatingAdmissionWebhook that intercepts pod creation requests to inject the proxy container.

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To act as a load balancer for traffic

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To monitor the health of pods

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To store mesh configuration data

Question 15

You are debugging an Istio installation issue. Which command allows you to view the currently applied IstioOperator configuration in the cluster?

Accepted Answer

kubectl get istiooperator -n istio-system. The 'kubectl get istiooperator -n istio-system' command displays the custom resources that define the Istio installation.

Answer

istioctl manifest get

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helm get values istio

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istioctl config dump

Question 16

Which TWO of the following are valid ways to verify the status of an Istio control plane deployment?

Accepted Answer

istioctl verify-install. Using 'istioctl verify-install' checks the health of the control plane, and checking the status of the 'istiod' deployment via kubectl is a standard Kubernetes verification method.

Answer

istioctl proxy-status

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istioctl mesh-check

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kubectl describe ingressgateway

Question 17

Which TWO fields in the IstioOperator CR are commonly used to configure ingress gateway resources?

Accepted Answer

spec.components.ingressGateways. The 'spec.components.ingressGateways' and 'spec.values.gateways.istio-ingressgateway' are the standard configuration areas for gateway resources.

Answer

spec.gateways.enabled

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spec.pilot.gateways

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spec.meshConfig.ingress

Question 18

When planning an Istio upgrade, which THREE steps are critical for a canary upgrade strategy?

Accepted Answer

Install the new version as a separate revision. Canary upgrades require installing a new revision, updating the namespace label, and then performing a rolling restart of the application pods.

Answer

Perform an in-place upgrade of the existing istiod

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Delete the old IstioOperator CR

Question 19

Which THREE commands can be used to manage or inspect the Istio mesh configuration?

Accepted Answer

istioctl version. The 'istioctl' tool provides 'analyze', 'proxy-config', and 'version' commands for mesh inspection and management.

Answer

istioctl deploy

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istioctl upgrade

Question 20

Which THREE actions occur when you label a namespace with 'istio-injection=enabled'?

Accepted Answer

New pods created in the namespace are injected with a sidecar. The webhook controller is notified, existing pods are not affected, but new pods will have the sidecar injected automatically.

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The istiod deployment is scaled up

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All existing pods are immediately restarted