Header and query match

Documentation

Use header and query matchers in a route delegation setup.

Configuration overview

In this guide you walk through a route delegation example where headers and query parameters are added as matchers to the parent and child HTTPRoute resources. A routing hierarchy can be created only if the child defines the same header and query matchers that the parent HTTPResource defines. You can optionally define additional header or query matchers on the child HTTPRoute resource.

For example, if the parent HTTPRoute resource specifies the header header, the child must specify the same header matcher.

The following image illustrates the route delegation hierarchy:

parent HTTPRoute:

The parent HTTPRoute resource delegates traffic as follows:
- /anything/team1 delegates traffic to the child HTTPRoute resource child-team1 in namespace team1 for requests that include the header1; val1 request header and the query1=val1 query parameter.
- /anything/team2 delegates traffic to the child HTTPRoute resource child-team2 in namespace team2 for requests that include the header2: val2 request header and the query2=val2 query parameter.

child-team1 HTTPRoute:

The child HTTPRoute resource child-team1 matches incoming traffic for the /anything/team1/foo prefix path if the header1: val1 and headerX: valX request headers and query1=val1 and queryX=valX query parameters are present in the request. Requests that match these conditions are forwarded to the httpbin app in namespace team1. Note that the headers and query parameters are a superset of the headers and query parameters that the parent HTTPRoute resource defines.

child-team2 HTTPRoute:

The child HTTPRoute resource child-team2 matches incoming traffic for the /anything/team2/bar exact prefix path if the headerX: valX request header and queryX=valX query parameter are present in the request. Because the child HTTPRoute resource does not specify the same header and query parameters that the parent HTTPRoute specified, the route is considered invalid.

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

Setup

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

Route 1 matches on the following conditions. If these conditions are met, the routing decision is delegated to a child HTTPRoute resource in the team1 namespace.
- path prefix match on /anything/team1
- exact header match on header1=val1
- exact query parameter match on query1=val1
Route 2 matches on the following conditions. If these conditions are met, the routing decision is delegated to a child HTTPRoute resource in the team2 namespace.
- path prefix match on /anything/team2
- exact header match on header2=val2
- exact query parameter match on query2=val2

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
      headers:
      - type: Exact
        name: header1
        value: val1
      queryParams:
      - type: Exact
        name: query1
        value: val1
    backendRefs:
    - group: gateway.networking.k8s.io
      kind: HTTPRoute
      name: "*"
      namespace: team1
  - matches:
    - path:
        type: PathPrefix
        value: /anything/team2
      headers:
      - type: Exact
        name: header2
        value: val2
      queryParams:
      - type: Exact
        name: query2
        value: val2
    backendRefs:
    - group: gateway.networking.k8s.io
      kind: HTTPRoute
      name: "*"
      namespace: team2
EOF

Create the child-team1 HTTPRoute resource in the team1 namespace that matches traffic on the /anything/team1/foo path prefix if the header1=val1 and headerX=valX request headers and the query1=val1 and queryX=valX query parameters are present in the request. Requests that meet these conditions are forwarded to the httpbin app in the team1 namespace.

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
      headers:
      - type: Exact
        name: header1
        value: val1
      - type: Exact
        name: headerX
        value: valX
      queryParams:
      - type: Exact
        name: query1
        value: val1
      - type: Exact
        name: queryX
        value: valX
    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 if the headerX=valX request header and queryX=valX query parameter are present in the request. Requests that meets these conditions are forwarded to the httpbin app in the team2 namespace.

kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: child-team2
  namespace: team2
spec:
  rules:
  - matches:
    - path:
        type: Exact
        value: /anything/team2/foo
      headers:
      - type: Exact
        name: headerX
        value: valX
      queryParams:
      - type: Exact
        name: queryX
        value: valX
    backendRefs:
    - name: httpbin
      port: 8000
EOF

Send a request to the delegation.example domain along the /anything/team1/foo path with the header1=val1 request header and the query1=val1 query parameter. Verify that you get back a 404 HTTP response code. Although you included the header and query parameters that are defined on the parent HTTPRoute resource, the headers and query parameters that the child HTTPRoute resource matches on are missing in your request.
curl -i http://$INGRESS_GW_ADDRESS:8080/anything/team1/foo?query1=val1 \ -H "host: delegation.example:8080" -H "header1: val1"
curl -i localhost:8080/anything/team1/foo1?query1=val1 \ -H "host: delegation.example" -H "header1: val1"
Example output:
```
HTTP/1.1 404 Not Found
date: Mon, 06 May 2024 16:01:48 GMT
server: envoy
transfer-encoding: chunked
```

Send another request to the delegation.example domain along the /anything/team1/foo path. This time, you include all of the header and query parameters that the parent and child HTTPRoute resources defined. Verify that you get back a 200 HTTP response code.

curl -i http://$INGRESS_GW_ADDRESS:8080/anything/team1/foo?query1=val1&queryX=valX \
-H "host: delegation.example:8080" -H "header1: val1" -H "headerX: valX"

curl -i localhost:8080/anything/team1/foo1?query1=val1&queryX=valX \
-H "host: delegation.example:8080" -H "header1: val1" -H "headerX: valX"

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

Send another request to the delegation.example domain along the /anything/team2/bar path that is configured on the child-team2 HTTPRoute resource and include all of the header and query parameters that are defined on the parent and child HTTPRoute resources. Verify that you get back a 404 HTTP response code. Because the child-team2 HTTPRoute resource does not specify the same header and query matchers as the parent HTTPRoute resource, the routing configuration is considered invalid.
curl -i http://$INGRESS_GW_ADDRESS:8080/anything/team2/bar?queryX=valX&query2=val2 \ -H "host: delegation.example:8080" -H "headerX: valX" -H "header2: val2"
curl -i localhost:8080/anything/team2/bar?queryX=valX&query2=val2 \ -H "host: delegation.example:8080" -H "headerX: valX" -H "header2: val2"
Example output:
```
HTTP/1.1 404 Not Found
date: Mon, 06 May 2024 16:01:48 GMT
server: envoy
transfer-encoding: chunked
```

Cleanup

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 -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

Multi-level delegation Policy inheritance