You simply add the list of static hosts or DNS names to your Upstream resource and then reference the Upstream in your HTTPRoute resource. Unlike Upstreams that are dynamically created by using the discovery feature in Gloo Gateway, static Upstream resources must be created manually by the user.

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 a static Upstream

  1. Create a static Upstream resource that routes requests to the JSON testing API.

    kubectl apply -f- <<EOF
apiVersion: gloo.solo.io/v1
kind: Upstream
metadata:
  name: json-upstream
spec:
  static:
    hosts:
      - addr: jsonplaceholder.typicode.com
        port: 80
EOF

  2. Create a RouteOption resource that rewrites the hostname to the jsonplaceholder.typicode.com.

    kubectl apply -f- <<EOF
apiVersion: gateway.solo.io/v1
kind: RouteOption
metadata:
  name: rewrite
  namespace: default
spec:
  options:
    hostRewrite: 'jsonplaceholder.typicode.com'
EOF

  3. Create an HTTPRoute resource that routes traffic on the static.example domain to your Upstream resource. To ensure that your request can be forwarded to the JSON testing API, you must also reference the RouteOption resource that rewrites hostnames to jsonplaceholder.typicode.com.

    kubectl apply -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: static-upstream
  namespace: default
spec:
  parentRefs:
  - name: http
    namespace: gloo-system
  hostnames:
    - static.example
  rules:
    - backendRefs:
      - name: json-upstream
        kind: Upstream
        group: gloo.solo.io
      filters:
      - type: ExtensionRef
        extensionRef:
          group: gateway.solo.io
          kind: RouteOption
          name: rewrite
EOF

  4. Send a request to your Upstream and verify that you get back a 200 HTTP response code and a list of posts.

    curl -vik http://$INGRESS_GW_ADDRESS:8080/posts -H "host: static.example:8080"
    curl -vik localhost:8080/posts -H "host: static.example:8080"

    Example output:

    <
 [
   {
     "userId": 1,
     "id": 1,
     "title": "sunt aut facere repellat provident occaecati excepturi optio reprehenderit",
     "body": "quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto"
   },
   {
     "userId": 1,
     "id": 2,
     "title": "qui est esse",
     "body": "est rerum tempore vitae\nsequi sint nihil reprehenderit dolor beatae ea dolores neque\nfugiat blanditiis voluptate porro vel nihil molestiae ut reiciendis\nqui aperiam non debitis possimus qui neque nisi nulla"
   },
   {
     "userId": 1,
     "id": 3,
     "title": "ea molestias quasi exercitationem repellat qui ipsa sit aut",
     "body": "et iusto sed quo iure\nvoluptatem occaecati omnis eligendi aut ad\nvoluptatem doloribus vel accusantium quis pariatur\nmolestiae porro eius odio et labore et velit aut"
   },
   {
     "userId": 1,
     "id": 4,
     "title": "eum et est occaecati",
     "body": "ullam et saepe reiciendis voluptatem adipisci\nsit amet autem assumenda provident rerum culpa\nquis hic commodi nesciunt rem tenetur doloremque ipsam iure\nquis sunt voluptatem rerum illo velit"
   },
...

Cleanup

You can optionally remove the resources that you created.

kubectl delete httproute static-upstream
kubectl delete routeoption rewrite
kubectl delete upstream json-upstream