Resource Labels

This page presents the various resource labels that Istio supports to control its behavior.

istio.io/rev

Nameistio.io/rev
Feature StatusAlpha
Resource Types[Namespace]
Description

Istio control plane revision associated with the resource; e.g. canary

networking.istio.io/gatewayPort

Namenetworking.istio.io/gatewayPort
Feature StatusAlpha
Resource Types[Service]
Description

IstioGatewayPortLabel overrides the default 15443 value to use for a multi-network gateway’s port

service.istio.io/canonical-name

Nameservice.istio.io/canonical-name
Feature StatusAlpha
Resource Types[Pod]
Description

The name of the canonical service a workload belongs to

service.istio.io/canonical-revision

Nameservice.istio.io/canonical-revision
Feature StatusAlpha
Resource Types[Pod]
Description

The name of a revision within a canonical service that the workload belongs to

sidecar.istio.io/inject

Namesidecar.istio.io/inject
Feature StatusBeta
Resource Types[Pod]
Description

Specifies whether or not an Envoy sidecar should be automatically injected into the workload.

topology.istio.io/cluster

Nametopology.istio.io/cluster
Feature StatusAlpha
Resource Types[Pod]
Description

This label is applied to a workload internally that identifies the Kubernetes cluster containing the workload. The cluster ID is specified during Istio installation for each cluster via values.global.multiCluster.clusterName. It should be noted that this is only used internally within Istio and is not an actual label on workload pods. If a pod contains this label, it will be overridden by Istio internally with the cluster ID specified during Istio installation. This label provides a way to select workloads by cluster when using DestinationRules. For example, a service owner could create a DestinationRule containing a subset per cluster and then use these subsets to control traffic flow to each cluster independently.

topology.istio.io/network

Nametopology.istio.io/network
Feature StatusBeta
Resource Types[Namespace Pod Service]
Description

A label used to identify the network for one or more pods. This is used internally by Istio to group pods resident in the same L3 domain/network. Istio assumes that pods in the same network are directly reachable from one another. When pods are in different networks, an Istio Gateway (e.g. east-west gateway) is typically used to establish connectivity (with AUTO_PASSTHROUGH mode). This label can be applied to the following resources to help automate Istio’s multi-network configuration.

  • Istio System Namespace: Applying this label to the system namespace establishes a default network for pods managed by the control plane. This is typically configured during control plane installation using an admin-specified value.

  • Pod: Applying this label to a pod allows overriding the default network on a per-pod basis. This is typically applied to the pod via webhook injection, but can also be manually specified on the pod by the service owner. The Istio installation in each cluster configures webhook injection using an admin-specified value.

  • Gateway Service: Applying this label to the Service for an Istio Gateway, indicates that Istio should use this service as the gateway for the network, when configuring cross-network traffic. Istio will configure pods residing outside of the network to access the Gateway service via spec.externalIPs, status.loadBalancer.ingress[].ip, or in the case of a NodePort service, the Node’s address. The label is configured when installing the gateway (e.g. east-west gateway) and should match either the default network for the control plane (as specified by the Istio System Namespace label) or the network of the targeted pods.

topology.istio.io/subzone

Nametopology.istio.io/subzone
Feature StatusBeta
Resource Types[Node]
Description

User-provided node label for identifying the locality subzone of a workload. This allows admins to specify a more granular level of locality than what is offered by default with Kubernetes regions and zones.

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