Multi-level delegation

Configuration overview link

In this guide you walk through a route delegation example that demonstrates route delegation from a parent HTTPRoute resource to a child HTTPRoute resource, and from a child HTTPRoute resource to a grandchild HTTPRoute resource. The following image illustrates the route delegation hierarchy:

• The parent HTTPRoute resource parent delegates traffic as follows:
  • /anything/team1 delegates traffic to the child HTTPRoute resource child-team1 in namespace team1.
  • /anything/team2 delegates traffic to the child HTTPRoute resource child-team2 in namespace team2.
• The child HTTPRoute resource child-team1 matches incoming traffic for the /anything/team1/foo prefix path and routes that traffic to the httpbin app in the team1 namespace.
• The child HTTPRoute resource child-team2 delegates traffic on the /anything/team2/grandchild to a grandchild HTTPRoute resource in the team2 namespace.
• The grandchild HTTPRoute resource grandchild-team2 matches incoming traffic for the /anything/team2/grandchild/.* regex path and routes that traffic to the httpbin app in the team2 namespace.

Before you begin link

1. Create the namespaces for team1 and team2.

     kubectl create namespace team1
   kubectl create namespace team2
     

2. Deploy the httpbin app into both namespaces.

     kubectl -n team1 apply -f https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/policy-demo/httpbin.yaml
   kubectl -n team2 apply -f https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/policy-demo/httpbin.yaml
     

3. Verify that the httpbin apps are up and running.

     kubectl get pods -n team1
   kubectl get pods -n team2
     

   Example output:

     NAME                      READY   STATUS    RESTARTS   AGE
   httpbin-f46cc8b9b-bzl9z   3/3     Running   0          7s
   NAME                      READY   STATUS    RESTARTS   AGE
   httpbin-f46cc8b9b-nhtmg   3/3     Running   0          6s
     

Setup link

1. Create the parent HTTPRoute resource that matches incoming traffic on the delegation.example domain. The HTTPRoute resource specifies two routes:

   • /route1/team1: The routing decision is delegated to a child HTTPRoute resource in the team1 namespace.
   • /route2/team2: The routing decision is delegated to a child HTTPRoute resource in the team2 namespace.

     kubectl apply -f- <<EOF
   apiVersion: gateway.networking.k8s.io/v1
   kind: HTTPRoute
   metadata:
     name: parent
     namespace: gloo-system
   spec:
     hostnames:
     - delegation.example
     parentRefs:
     - name: http
     rules:
     - matches:
       - path:
           type: PathPrefix
           value: /anything/team1
       backendRefs:
       - group: gateway.networking.k8s.io
         kind: HTTPRoute
         name: "*"
         namespace: team1
     - matches:
       - path:
           type: PathPrefix
           value: /anything/team2
       backendRefs:
       - group: gateway.networking.k8s.io
         kind: HTTPRoute
         name: "*"
         namespace: team2
   EOF
     

2. Create the child-team1 HTTPRoute resource in the team1 namespace that matches traffic on the /anything/team1/foo prefix and routes traffic to the httpbin app in the team1 namespace. The child HTTPRoute resource does not select a specific parent HTTPRoute resource. Because of that, the child HTTPRoute resource is automatically selected by all parent HTTPRoute resources that delegate traffic to this child.

     kubectl apply -f- <<EOF
   apiVersion: gateway.networking.k8s.io/v1
   kind: HTTPRoute
   metadata:
     name: child-team1
     namespace: team1
   spec:
     rules:
     - matches:
       - path:
           type: PathPrefix
           value: /anything/team1/foo
       backendRefs:
       - name: httpbin
         port: 8000
   EOF
     

3. Create the child-team2 HTTPRoute resource in the team2 namespace that matches traffic on the /anything/team2/grandchild/ prefix and delegates traffic to an HTTPRoute resource in the team2 namespace. Note that because the child delegates traffic to a grandchild, a PathPrefix matcher must be used.

     kubectl apply -f- <<EOF
   apiVersion: gateway.networking.k8s.io/v1
   kind: HTTPRoute
   metadata:
     name: child-team2
     namespace: team2
   spec:
     rules:
     - matches:
       - path:
           type: PathPrefix
           value: /anything/team2/grandchild/
       backendRefs:
       - group: gateway.networking.k8s.io
         kind: HTTPRoute
         name: "*"
         namespace: team2
   EOF
     

4. Create a grandchild HTTPRoute resource that matches traffic on the /anything/team2/grandchild/.* regex path and routes traffic to the httpbin app in the team2 namespace.

     kubectl apply -f- <<EOF
   apiVersion: gateway.networking.k8s.io/v1
   kind: HTTPRoute
   metadata:
     name: grandchild
     namespace: team2
   spec:
     rules:
     - matches:
       - path:
           type: RegularExpression
           value: /anything/team2/grandchild/.*
       backendRefs:
       - name: httpbin
         port: 8000
   EOF
     

5. Send a request to the delegation.example domain along the /anything/team1/foo path. Verify that you get back a 200 HTTP response code.

     curl -I http://$INGRESS_GW_ADDRESS:8080/anything/team1/foo \
   -H "host: delegation.example:8080"
     

     curl -I localhost:8080/anything/team1/foo \
   -H "host: delegation.example"
     

   Example output:

     HTTP/1.1 200 OK
   access-control-allow-credentials: true
   access-control-allow-origin: *
   content-type: application/json; encoding=utf-8
   date: Mon, 06 May 2024 15:59:32 GMT
   x-envoy-upstream-service-time: 0
   server: envoy
   transfer-encoding: chunked
     

6. Send another request to the delegation.example domain along the /anything/team1/bar path. Verify that you get back a 404 HTTP response code, because this route is not specified in the child HTTPRoute resource child-team1.

     curl -I http://$INGRESS_GW_ADDRESS:8080/anything/team1/bar \
   -H "host: delegation.example:8080"
     

     curl -I localhost:8080/anything/team1/bar \
   -H "host: delegation.example"
     

   Example output:

     HTTP/1.1 404 Not Found
   date: Mon, 06 May 2024 16:01:48 GMT
   server: envoy
   transfer-encoding: chunked
     

7. Send another request to the delegation.example domain. This time, you use the /anything/team2/grandchild/bar path that is configured on the grandchild HTTPRoute resource. Verify that you get back a 200 HTTP response code.

     curl -I http://$INGRESS_GW_ADDRESS:8080/anything/team2/grandchild/bar \
   -H "host: delegation.example:8080"
     

     curl -I localhost:8080/anything/team2/grandchild/bar \
   -H "host: delegation.example"
     

   Example output:

     HTTP/1.1 200 OK
   access-control-allow-credentials: true
   access-control-allow-origin: *
   content-type: application/json; encoding=utf-8
   date: Mon, 06 May 2024 15:59:32 GMT
   x-envoy-upstream-service-time: 0
   server: envoy
   transfer-encoding: chunked
     

8. Send another request to the delegation.example domain along the /anything/team2/grandchild/foo path. Because the grandchild HTTPRoute resource uses a regular expression to match incoming traffic, you can use any valid endpoint in the httpbin app to route traffic to the httpbin app in the team2 namespace.
   

     curl -I http://$INGRESS_GW_ADDRESS:8080/anything/team2/grandchild/foo \
   -H "host: delegation.example:8080"
     

     curl -I localhost:8080/anything/team2/grandchild/foo \
   -H "host: delegation.example"
     

   Example output:

     HTTP/1.1 200 OK
   access-control-allow-credentials: true
   access-control-allow-origin: *
   content-type: application/json; encoding=utf-8
   date: Mon, 06 May 2024 15:59:32 GMT
   x-envoy-upstream-service-time: 0
   server: envoy
   transfer-encoding: chunked
     

Cleanup link

You can remove the resources that you created in this guide.

  kubectl delete httproute parent -n gloo-system
kubectl delete httproute child-team1 -n team1
kubectl delete httproute child-team2 -n team2
kubectl delete httproute grandchild -n team2
kubectl delete -n team1 -f https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/policy-demo/httpbin.yaml
kubectl delete -n team2 -f https://raw.githubusercontent.com/solo-io/gloo-mesh-use-cases/main/policy-demo/httpbin.yaml
kubectl delete namespaces team1 team2