Instead of referencing a Kubernetes service in your HTTPRoute directly, you can create an Upstream resource that represents your Kubernetes service and reference that Upstream in your HTTPRoute. With Kubernetes Upstream resources, you can configure additional settings for your Kubernetes service that cannot be configured when using the KubernetesService resource. For example, you can require communication to your Kubernetes service to use the HTTP/2 protocol, or add health checks. Because Upstreams bypass the kube-proxy, you can also improve load balancing times for your workloads.

Before you begin

  1. Follow the Get started guide to install Gloo Gateway, set up a gateway resource, and deploy the httpbin sample app.

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

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

Set up the Upstream

  1. Create the Petstore sample app.

      kubectl apply -f https://raw.githubusercontent.com/solo-io/gloo/v1.16.x/example/petstore/petstore.yaml

  2. Create an Upstream resource for the Petstore app.

      kubectl apply -f- <<EOF
apiVersion: gloo.solo.io/v1
kind: Upstream
metadata:
  name: petstore
  namespace: gloo-system
spec:
  kube:
    serviceName: petstore
    serviceNamespace: default
    servicePort: 8080
EOF

  3. Create an HTTPRoute resource that references the Upstream that you created.

      kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: kube-upstream
  namespace: gloo-system
spec:
  parentRefs:
  - name: http
    namespace: gloo-system
  hostnames:
    - kube.example
  rules:
    - backendRefs:
      - name: petstore
        kind: Upstream
        group: gloo.solo.io
EOF

  4. Send a request to the Petstore app.

      curl -vik http://$INGRESS_GW_ADDRESS:8080/api/pets -H "host: kube.example:8080"
  
      curl -vik localhost:8080/api/pets -H "host: kube.example:8080"

    Example output:

      ...
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
...
[{"id":1,"name":"Dog","status":"available"},{"id":2,"name":"Cat","status":"pending"}]

Cleanup

Remove the resources that you created.

  kubectl delete httproute kube-upstream -n gloo-system
kubectl delete upstream petstore -n gloo-system
kubectl delete -f https://raw.githubusercontent.com/solo-io/gloo/v1.16.x/example/petstore/petstore.yaml