days to Istio 1.5

JwtFailureDueToInvalidServicePortPrefix

This message occurs when a authentication Policy specifies the use of JWT authentication, but the targeted Kubernetes services is not configured properly. A properly targeted Kubernetes service requires the port to be named with a prefix of http|http2|https (see Protocol Selection) and also requires the protocol to be TCP; an empty protocol is acceptable as TCP is the default value.

Example

You will receive this message:

Warn [IST0119] (Policy secure-httpbin.default) Authentication policy with JWT targets Service with invalid port specification (port: 8080, name: svc-8080, protocol: TCP, targetPort: 80).

when your cluster has following policy:

apiVersion: authentication.istio.io/v1alpha1
kind: Policy
metadata:
  name: secure-httpbin
  namespace: default
spec:
  targets:
    - name: httpbin
  origins:
    - jwt:
        issuer: "testing@secure.istio.io"
        jwksUri: "https://raw.githubusercontent.com/istio/istio-1.4/security/tools/jwt/samples/jwks.json"

that targets the following service:

apiVersion: v1
kind: Service
metadata:
  name: httpbin
  namespace: default
  labels:
    app: httpbin
spec:
  ports:
  - name: svc-8080
    port: 8080
    targetPort: 80
    protocol: TCP
  selector:
    app: httpbin

In this example, the port svc-8080 does follow the syntax: name: <http|https|http2>[-<suffix>].

How to resolve

  • JWT authentication is only supported over http, https or http2. Rename the Service port name to conform with <http|https|http2>[-<suffix>]