Chapter 11. Configuring access to Knative services

Procedure

1. 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.

2. Apply the Service resource:

   $ oc apply -f <filename>

3. Create a RequestAuthentication resource in each serverless application namespace that is a member in the ServiceMeshMemberRoll object:

   apiVersion: security.istio.io/v1beta1
   kind: RequestAuthentication
   metadata:
     name: jwt-example
     namespace: <namespace>
   spec:
     jwtRules:
     - issuer: testing@secure.istio.io
       jwksUri: https://raw.githubusercontent.com/istio/istio/release-1.8/security/tools/jwt/samples/jwks.json

4. Apply the RequestAuthentication resource:

   $ oc apply -f <filename>

5. Allow access to the RequestAuthenticaton resource from system pods for each serverless application namespace that is a member in the ServiceMeshMemberRoll object, by creating the following AuthorizationPolicy resource:

   apiVersion: security.istio.io/v1beta1
   kind: AuthorizationPolicy
   metadata:
     name: allowlist-by-paths
     namespace: <namespace>
   spec:
     action: ALLOW
     rules:
     - to:
       - operation:
           paths:
           - /metrics 1
           - /healthz 2

   1

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

   2

   The path on your application to probe by system pod.

6. Apply the AuthorizationPolicy resource:

   $ oc apply -f <filename>

7. For each serverless application namespace that is a member in the ServiceMeshMemberRoll object, create the following AuthorizationPolicy resource:

   apiVersion: security.istio.io/v1beta1
   kind: AuthorizationPolicy
   metadata:
     name: require-jwt
     namespace: <namespace>
   spec:
     action: ALLOW
     rules:
     - from:
       - source:
          requestPrincipals: ["testing@secure.istio.io/testing@secure.istio.io"]

8. Apply the AuthorizationPolicy resource:

   $ oc apply -f <filename>

Verification

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

   Example command

   $ curl http://hello-example-1-default.apps.mycluster.example.com/

   Example output

   RBAC: access denied

2. Verify the request with a valid JWT.

   1. Get the valid JWT token:

      $ TOKEN=$(curl https://raw.githubusercontent.com/istio/istio/release-1.8/security/tools/jwt/samples/demo.jwt -s) && echo "$TOKEN" | cut -d '.' -f2 - | base64 --decode -

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

      $ curl -H "Authorization: Bearer $TOKEN"  http://hello-example-1-default.apps.example.com

      The request is now allowed:

      Example output

      Hello OpenShift!

Procedure

1. 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.

2. Apply the Service resource:

   $ oc apply -f <filename>

3. 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):

   Important

   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.

4. Apply the Policy resource:

   $ oc apply -f <filename>

Verification

1. 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.

2. Verify the request with a valid JWT.

   1. 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 -

   2. 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!