TIS1107 - Preferred Gateway Nomenclature

The preferred nomenclature for gateways in Istio is [gateway namespace]/[gateway name].

Recommendation: Use Preferred Gateway Nomenclature [namespace]/[gateway name]

To ensure clear and unambiguous gateway references, always use the preferred nomenclature [gateway namespace]/[gateway name] in VirtualService configurations.

Examples

1. VirtualService with Incorrect Gateway Nomenclature

   apiVersion: networking.istio.io/v1beta1
   kind: VirtualService
   metadata:
     name: my-virtual-service
     namespace: example-namespace
   spec:
     hosts:
     - "my-app.example.com"
     gateways:
     - "my-gateway"
     http:
     - route:
       - destination:
           host: "my-app-service.example-namespace.svc.cluster.local"

   Explanation: The gateway field in the VirtualService is set as "my-gateway" without specifying the namespace. The preferred Istio nomenclature for referencing gateways is [gateway namespace]/[gateway name], which provides clarity and avoids conflicts when gateways with the same name exist in different namespaces.

Recommendation

Update the nomenclature of the gateways to the supported Istio format [gateway namespace]/[gateway name].

1. Update Gateway Nomenclature to Include Namespace

   Update the gateway reference to include both the namespace and the gateway name.

   apiVersion: networking.istio.io/v1beta1
   kind: VirtualService
   metadata:
     name: my-virtual-service
     namespace: example-namespace
   spec:
     hosts:
     - "my-app.example.com"
     gateways:
     - "example-namespace/my-gateway"
     http:
     - route:
       - destination:
           host: "my-app-service.example-namespace.svc.cluster.local"

   Explanation: Updating the gateway reference to "example-namespace/my-gateway" provides the complete and preferred nomenclature, avoiding ambiguity and ensuring that the correct gateway is used in the configuration.