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Delegation via labels

Use labels to delegate traffic from a parent HTTPRoute to different child HTTPRoutes.

Configuration overview

In this example, you learn how to use labels to delegate traffic. The parent HTTPRoute defines the labels that must be present on the child HTTPRoute to allow traffic to be forwarded.

You typically configure the parent to find an HTTPRoute with a specific label in a specific namespace. However, you can also use a wildcard for the namespace when you have multiple HTTPRoutes in different namespaces that can all receive delegated traffic. This configuration can significantly simplify your route delegation setup as it allows you to quickly add new child HTTPRoutes to the delegation chain without changing the parent HTTPRoute configuration.

Explore an example for delegating traffic to an HTTPRoute with a specific label in a specific namespace. To try out this example, see the Before you begin section and then continue with HTTPRoutes in specific namespaces.

parent HTTPRoute:

The parent HTTPRoute resource delegates traffic as follows:
- Requests to /anything/team1 are delegated to the child HTTPRoute resource child-team1 in namespace team1 with the delegation.gateway.solo.io/label: team1 label.
- Requests to /anything/team2 are delegated to the child HTTPRoute resource child-team2 in namespace team2 with the delegation.gateway.solo.io/label: team2 label.

child-team1 HTTPRoute:

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.

child-team2 HTTPRoute:

The child HTTPRoute resource child-team2 matches incoming traffic for the /anything/team1/bar prefix path and routes that traffic to the httpbin app in the team2 namespace.

Learn how to use a wildcard for the namespace to streamline your route delegation setup. To try out this example, see the Before you begin section and then continue with Use wildcard namespaces.

parent HTTPRoute:

The parent HTTPRoute resource delegates traffic as follows:
- Requests to / are delegated to all child HTTPRoute resources with the delegation.gateway.solo.io/label: wildcard label. The / matcher is used so that the child HTTPRoutes can define any path prefix that they want to match traffic on.

child-team1 HTTPRoute:

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 HTTPRoute is configured with the delegation.gateway.solo.io/label: wildcard label so that it can receive delegated traffic from the parent.

child-team2 HTTPRoute:

The child HTTPRoute resource child-team2 matches incoming traffic for the /anything/team1/bar prefix path and routes that traffic to the httpbin app in the team2 namespace. The HTTPRoute is configured with the delegation.gateway.solo.io/label: wildcard label so that it can receive delegated traffic from the parent.

Before you begin

Create the namespaces for team1 and team2.

  kubectl create namespace team1
kubectl create namespace team2

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

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

HTTPRoutes in specific namespaces

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

Route 1 matches traffic on the path prefix /anything/team1 and delegates traffic to the HTTPRoute with the delegation.gateway.solo.io/label: team1 label.
Route 2 matches traffic on the path prefix /anything/team2 and delegates traffic to the HTTPRoute with the delegation.gateway.solo.io/label: team2 label.

  kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
 name: parent
 namespace: gloo-system
spec:
 parentRefs:
 - name: http
 hostnames:
 - delegation.example
 rules:
 - matches:
   - path: 
       type: PathPrefix
       value: /anything/team1
   backendRefs:
   # Delegate to routes with the label delegation.gateway.solo.io/label:foobar
   # in the foo namespace
   - group: delegation.gateway.solo.io
     kind: label 
     name: team1
     namespace: team1
 - matches:
   - path: 
       type: PathPrefix
       value: /anything/team2
   backendRefs:
   # Delegate to routes with the label delegation.gateway.solo.io/label:foobar
   # in the foo namespace
   - group: delegation.gateway.solo.io
     kind: label 
     name: team2
     namespace: team2
EOF

Create the child-team1 HTTPRoute resource in the team1 namespace that matches traffic on the /anything/team1/foo path prefix. To delegate traffic to this HTTPRoute, you must label the route with the delegation.gateway.solo.io/label: team1 label that you defined on the parent HTTPRoute.

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

Create the child-team2 HTTPRoute resource in the team2 namespace that matches traffic on the /anything/team2/bar exact prefix. To delegate traffic to this HTTPRoute, you must label the route with the delegation.gateway.solo.io/label: team2 label that you defined on the parent HTTPRoute.

  kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: child-team2
  namespace: team2
  labels: 
    delegation.gateway.solo.io/label: team2
spec:
  rules:
  - matches:
    - path:
        type: Exact
        value: /anything/team2/bar
    backendRefs:
    - name: httpbin
      port: 8000
EOF

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
content-length: 509
x-envoy-upstream-service-time: 0
server: envoy

{
  "args": {},
  "headers": {
    "Accept": [
      "*/*"
    ],
    "Host": [
      "delegation.example:8080"
    ],
    "User-Agent": [
      "curl/8.7.1"
    ],
    "X-Envoy-Expected-Rq-Timeout-Ms": [
      "15000"
    ],
    "X-Forwarded-Proto": [
      "http"
    ],
    "X-Request-Id": [
     "65927858-2c6b-42ae-9278-8ff9d8bba3f8"
    ]
  },
  "origin": "10.0.64.27:49526",
  "url": "http://delegation.example:8080/anything/team1/foo",
  "data": "",
  "files": null,
  "form": null,
  "json": null
}

Send a request to the delegation.example domain along the /anything/team2/bar path. Verify that you also get back a 200 HTTP response code.

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

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

Example output:

  HTTP/1.1 200 OK
access-control-allow-credentials: true
access-control-allow-origin: *
content-type: application/json; encoding=utf-8
content-length: 509
x-envoy-upstream-service-time: 1
server: envoy

{
  "args": {},
  "headers": {
    "Accept": [
     "*/*"
    ],
    "Host": [
      "delegation.example:8080"
    ],
    "User-Agent": [
      "curl/8.7.1"
    ],
    "X-Envoy-Expected-Rq-Timeout-Ms": [
      "15000"
    ],
    "X-Forwarded-Proto": [
      "http"
    ],
    "X-Request-Id": [
      "d645dc37-5326-4b69-8c2c-4060e12ca4ff"
    ]
  },
  "origin": "10.0.64.27:53026",
  "url": "http://delegation.example:8080/anything/team2/bar",
  "data": "",
  "files": null,
  "form": null,
  "json": null
}

Use wildcard namespaces

Instead of routing to an HTTPRoute with a specific label in a specific namespace, you can use a wildcard for the namespace. This configuration can streamline your route delegation setup as it allows you to easily add new child HTTPRoutes to the delegation chain.

Update the parent HTTPRoute to delegate traffic to all child HTTPRoutes with the wildcard label.

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

Update the child-team1 HTTPRoute to add the delegation.gateway.solo.io/label: wildcard label so that the parent HTTPRoute can delegate traffic to this route.

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

Update the child-team2 HTTPRoute to also add the delegation.gateway.solo.io/label: wildcard label.

  kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: child-team2
  namespace: team2
  labels: 
    delegation.gateway.solo.io/label: wildcard
spec:
  rules:
  - matches:
    - path:
        type: Exact
        value: /anything/team2/bar
    backendRefs:
    - name: httpbin
      port: 8000
EOF

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
content-length: 509
x-envoy-upstream-service-time: 0
server: envoy

{
  "args": {},
  "headers": {
    "Accept": [
      "*/*"
    ],
    "Host": [
      "delegation.example:8080"
    ],
    "User-Agent": [
      "curl/8.7.1"
    ],
    "X-Envoy-Expected-Rq-Timeout-Ms": [
      "15000"
    ],
    "X-Forwarded-Proto": [
      "http"
    ],
    "X-Request-Id": [
     "65927858-2c6b-42ae-9278-8ff9d8bba3f8"
    ]
  },
  "origin": "10.0.64.27:49526",
  "url": "http://delegation.example:8080/anything/team1/foo",
  "data": "",
  "files": null,
  "form": null,
  "json": null
}

Send a request to the delegation.example domain along the /anything/team2/bar path. Verify that you also get back a 200 HTTP response code.

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

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

Example output:

  HTTP/1.1 200 OK
access-control-allow-credentials: true
access-control-allow-origin: *
content-type: application/json; encoding=utf-8
content-length: 509
x-envoy-upstream-service-time: 1
server: envoy

{
  "args": {},
  "headers": {
    "Accept": [
     "*/*"
    ],
    "Host": [
      "delegation.example:8080"
    ],
    "User-Agent": [
      "curl/8.7.1"
    ],
    "X-Envoy-Expected-Rq-Timeout-Ms": [
      "15000"
    ],
    "X-Forwarded-Proto": [
      "http"
    ],
    "X-Request-Id": [
      "d645dc37-5326-4b69-8c2c-4060e12ca4ff"
    ]
  },
  "origin": "10.0.64.27:53026",
  "url": "http://delegation.example:8080/anything/team2/bar",
  "data": "",
  "files": null,
  "form": null,
  "json": null
}

Cleanup

You can optionally remove the resources that you set up as part of 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 -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

Delegation via labels

Configuration overview link

Before you begin link

HTTPRoutes in specific namespaces link

Use wildcard namespaces link

Cleanup link

Configuration overview

Before you begin

HTTPRoutes in specific namespaces

Use wildcard namespaces

Cleanup