Pods and Services

To be part of a mesh, Kubernetes pods and services must satisfy the followingrequirements:

• Named service ports: Service ports must be named. The port name key/valuepairs must have the following syntax: name: <protocol>[-<suffix>]. SeeProtocol Selection formore details.

• Service association: A pod must belong to at least one Kubernetesservice even if the pod does NOT expose any port.If a pod belongs to multiple Kubernetes services,the services cannot use the same port number for different protocols, forinstance HTTP and TCP.

• Deployments with app and version labels: We recommend adding an explicitapp label and version label to deployments. Add the labels to thedeployment specification of pods deployed using the Kubernetes Deployment.The app and version labels add contextual information to the metrics andtelemetry Istio collects.

  • The app label: Each deployment specification should have a distinctapp label with a meaningful value. The app label is used to addcontextual information in distributed tracing.

  • The version label: This label indicates the version of the applicationcorresponding to the particular deployment.

• Application UIDs: Ensure your pods do not run applications as a userwith the user ID (UID) value of 1337.

• NET_ADMIN capability: If your cluster enforces pod security policies,pods must allow the NET_ADMIN capability. If you use the Istio CNI Plugin,this requirement no longer applies. To learn more about the NET_ADMINcapability, see Required pod capabilities, below.

Ports used by Istio

The following ports and protocols are used by Istio. Ensure that there are noTCP headless services using a TCP port used by one of Istio’s services.

Required pod capabilities

If pod security policiesare enforcedin your cluster and unless you use the Istio CNI Plugin, your pods must have theNET_ADMIN capability allowed. The initialization containers of the Envoyproxies require this capability.

To check if the NET_ADMIN capability is allowed for your pods, you need to check if theirservice accountcan use a pod security policy that allows the NET_ADMIN capability.If you haven’t specified a service account in your pods’ deployment, the pods run usingthe default service account in their deployment’s namespace.

To list the capabilities for a service account, replace <your namespace> and <your service account>with your values in the following command:

$ for psp in $(kubectl get psp -o jsonpath="{range .items[*]}{@.metadata.name}{'\n'}{end}"); do if [ $(kubectl auth can-i use psp/$psp --as=system:serviceaccount:<your namespace>:<your service account>) = yes ]; then kubectl get psp/$psp --no-headers -o=custom-columns=NAME:.metadata.name,CAPS:.spec.allowedCapabilities; fi; done

For example, to check for the default service account in the default namespace, run the following command:

$ for psp in $(kubectl get psp -o jsonpath="{range .items[*]}{@.metadata.name}{'\n'}{end}"); do if [ $(kubectl auth can-i use psp/$psp --as=system:serviceaccount:default:default) = yes ]; then kubectl get psp/$psp --no-headers -o=custom-columns=NAME:.metadata.name,CAPS:.spec.allowedCapabilities; fi; done

If you see NET_ADMIN or * in the list of capabilities of one of the allowedpolicies for your service account, your pods have permission to run the Istio init containers.Otherwise, you will need to provide the permission.

See also

Installing the Sidecar

Install the Istio sidecar in application pods automatically using the sidecar injector webhook or manually using istioctl CLI.

Demystifying Istio's Sidecar Injection Model

De-mystify how Istio manages to plugin its data-plane components into an existing deployment.

Install Istio with the Istio CNI plugin

Install and use Istio with the Istio CNI plugin, allowing operators to deploy services with lower privilege.

DNS Certificate Management

Provision and manage DNS certificates in Istio.

Secure Webhook Management

A more secure way to manage Istio webhooks.

Customizable Install with Helm

Install and configure Istio for in-depth evaluation or production use.