Using JSON Web Token authentication with Service Mesh 1.x - Knative Serving | Serverless

You can use JSON Web Token (JWT) authentication with Knative services by using Service Mesh 1.x and OpenShift Serverless. To do this, you must create a policy in the application namespace that is a member of the ServiceMeshMemberRoll object. You must also enable sidecar injection for the service.

Configuring JSON Web Token authentication for Service Mesh 1.x and OpenShift Serverless

Adding sidecar injection to pods in system namespaces, such as knative-serving and knative-serving-ingress, is not supported when Kourier is enabled.

Prerequisites

You have installed the OpenShift Serverless Operator, Knative Serving, and Red Hat OpenShift Service Mesh on your cluster.
Install the OpenShift CLI (oc).
You have created a project or have access to a project with the appropriate roles and permissions to create applications and other workloads in OpenShift Dedicated.

Procedure

Add the sidecar.istio.io/inject="true" annotation to your service:

Example service

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: <service_name>
spec:
  template:
    metadata:
      annotations:
        sidecar.istio.io/inject: "true" (1)
        sidecar.istio.io/rewriteAppHTTPProbers: "true" (2)
...

1	Add the `sidecar.istio.io/inject="true"` annotation.
2	You must set the annotation `sidecar.istio.io/rewriteAppHTTPProbers: "true"` in your Knative service, because OpenShift Serverless versions 1.14.0 and higher use an HTTP probe as the readiness probe for Knative services by default.

Apply the Service resource:
```
$ oc apply -f <filename>
```

Create a policy in a serverless application namespace which is a member in the ServiceMeshMemberRoll object, that only allows requests with valid JSON Web Tokens (JWT):

The paths /metrics and /healthz must be included in excludedPaths because they are accessed from system pods in the knative-serving namespace.

apiVersion: authentication.istio.io/v1alpha1
kind: Policy
metadata:
  name: default
  namespace: <namespace>
spec:
  origins:
  - jwt:
      issuer: testing@secure.istio.io
      jwksUri: "https://raw.githubusercontent.com/istio/istio/release-1.6/security/tools/jwt/samples/jwks.json"
      triggerRules:
      - excludedPaths:
        - prefix: /metrics (1)
        - prefix: /healthz (2)
  principalBinding: USE_ORIGIN

1	The path on your application to collect metrics by system pod.
2	The path on your application to probe by system pod.

Apply the Policy resource:
```
$ oc apply -f <filename>
```

Verification

If you try to use a curl request to get the Knative service URL, it is denied:

$ curl http://hello-example-default.apps.mycluster.example.com/

Example output

Origin authentication failed.

Verify the request with a valid JWT.

Get the valid JWT token:

$ TOKEN=$(curl https://raw.githubusercontent.com/istio/istio/release-1.6/security/tools/jwt/samples/demo.jwt -s) && echo "$TOKEN" | cut -d '.' -f2 - | base64 --decode -

Access the service by using the valid token in the curl request header:

$ curl http://hello-example-default.apps.mycluster.example.com/ -H "Authorization: Bearer $TOKEN"

The request is now allowed:

Example output

Hello OpenShift!