Query parameter

Specify a set of URL query parameters which requests must match in entirety.

For more information, see the Kubernetes Gateway API documentation.

Before you begin

  1. Follow the Get started guide to install kgateway.

  2. Follow the Sample app guide to create a gateway proxy with an HTTP listener and deploy the httpbin sample app.

  3. Get the external address of the gateway and save it in an environment variable. 

    export INGRESS_GW_ADDRESS=$(kubectl get svc -n kgateway-system http -o jsonpath="{.status.loadBalancer.ingress[0]['hostname','ip']}")
echo $INGRESS_GW_ADDRESS  
    kubectl port-forward deployment/http -n kgateway-system 8080:8080

Set up query parameter matching

  1. Create an HTTPRoute resource for the match.example domain that matches incoming requests with a user=me query parameter.

    kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: httpbin-match
  namespace: httpbin
spec:
  parentRefs:
    - name: http
      namespace: kgateway-system
  hostnames:
    - match.example
  rules:
    - matches:
      - queryParams: 
          - type: Exact
            value: me
            name: user
      backendRefs:
        - name: httpbin
          port: 8000
EOF

  2. Send a request to the /status/200 path of the httpbin app on the match.example domain without any query parameters. Verify that your request is not forwarded to the httpbin app because no matching query parameter is found. 

    curl -vi http://$INGRESS_GW_ADDRESS:8080/status/200 -H "host: match.example:8080"
    curl -vi localhost:8080/status/200 -H "host: match.example"

    Example output:

    * Mark bundle as not supporting multiuse
< HTTP/1.1 404 Not Found
HTTP/1.1 404 Not Found
< date: Sat, 04 Nov 2023 03:45:39 GMT
date: Sat, 04 Nov 2023 03:45:39 GMT
< server: envoy
server: envoy
< content-length: 0
content-length: 0

  3. Send a request to the /status/200 path of the httpbin app on the match.example domain. This time, you provide the user=me query parameter. Verify that your request now succeeds and that you get back a 200 HTTP response code. 

    curl -vi "http://$INGRESS_GW_ADDRESS:8080/status/200?user=me" -H "host: match.example:8080"
    curl -vi "localhost:8080/status/200?user=me" -H "host: match.example"

    Example output:

    * Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< access-control-allow-credentials: true
access-control-allow-credentials: true
< access-control-allow-origin: *
access-control-allow-origin: *
< date: Sat, 04 Nov 2023 03:49:17 GMT
date: Sat, 04 Nov 2023 03:49:17 GMT
< content-length: 0
content-length: 0
< x-envoy-upstream-service-time: 1
x-envoy-upstream-service-time: 1
< server: envoy
server: envoy

Cleanup

You can remove the resources that you created in this guide. 
kubectl delete httproute httpbin-match -n httpbin
Path