K8 Gateway API Demo ⛩️

This repo is dedicated to showcasing the Gateway API. This material was created for the co-located event ServiceMesh Con for KubeCon NA 2022 talk that I delivered!

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Content

• K8 Gateway API Demo ⛩️
  • Pre requisites
  • Set up
  • 1 - Prefix match and header edit
  • 2 - Traffic Split
  • 3 - Add a new Gateway
  • Resources

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Pre requisites

• A Kubernetes cluster
• Istio, with the minimal profile
  • istioctl install --set profile=minimal -y

Set up

1. Install the Gateway API CRDs into your cluster.

kubectl apply -f 
https://github.com/kubernetes-sigs/gateway-api/releases/download/v0.5.1/standard-install.yaml

2. Clone this repo.

git clone https://github.com/xtineskim/gatewayapi-demo

3. Deploy the well-known sample application, httpbin. This will create a v1 and v2 deployment and service of the sample application in the default namespace.

kubectl apply -f gatewayapi-demo/0-setup/httpbin-v1-v2.yaml

4. Enable the sidecar injection to your default namespace (optional)

kubectl label ns default istio-injection=enabled --overwrite

5. Deploy your Gateway and HTTPRoute

kubectl apply -f  gatewayapi-demo/0-setup/gateway-api-demo.yaml

This Gateway is configured to use the Istio Gateway Controller 4. Get the EXTERNAL_IP of your Gateway

kubectl get gateway -n istio-ingress

Try curl-ing the EXTERNAL_IP. You should be able to get a 200 response.

curl -s -I -HHost:httpbin.example.com "<YOUR_EXTERNAL_IP>/get"

1 - Prefix match and header edit

The HTTPRoute is where the majority of the logic is handled. You have the ability to add matching on a URI, and also apply fileters to modify the header.

Currently, the HTTPRoute only exposes the /get path. Try curl-ing /headers.

curl -s -I -HHost:httpbin.example.com "<YOUR_EXTERNAL_IP>/get"

Let's say that your app devs wanted to add another path to their app. All they would have to do is specify in the HTTPRoute to match the new path. In 1-header/httproute.yaml, note the new match on the type: PathPrefix for /headers. Also note that this HTTPRoute is adding hello: world to the response headers.

Apply the HTTPRoute to access add a new headers.

kubectl apply -f gatewayapi-demo/1-header/httproute.yaml

Try curl-ing with /headers. You should now be able to access it. You should also see hello:world in it's response headers.

curl -s -I -HHost:httpbin.example.com "<YOUR_EXTERNAL_IP>/headers"

2 - Traffic Split

To split traffic between v1 and v2 of the the httpbin sample app, you can specify weights to state the percentage you want.

kubectl apply -f gatewayapi-demo/2-traffic-split/traffic-split-httproute.yaml

In this resource, you are specifying a 75%/25% split on v1 and v2.

If you curl your EXTERNAL_IP/get path, you should get a split between v1 and v2 according to the percentages!

curl -s -I -HHost:httpbin.example.com "<YOUR_EXTERNAL_IP>/get"

3 - Add a new Gateway

To try out another Gateway Controller (in this example, GKE L7 Load Balancer), you just need to instantiate your new Gateway with the appropriate gatewayClassName.

In the 3-newGateway/ directory, the gateway.yaml contains the new GKE L7 LB. If you look at the httproute, note the new entry in the parentRefs to allow traffic to flow from the new Gateway (in a different namespace) to the httpbin service.

First create a new namespace for the GKE L7

kubectl create ns gke-ingress

Create the new Gateway, and deploy the edited HTTPRoute

kubectl apply -f gatewayapi-demo/3-newGateway/gateway.yaml
kubectl apply -f gatewayapi-demo/3-newGateway/httproute.yaml

If you get the EXTERNAL_IP of your Gateways, you will now be able to interact with both Gateways and access the httpbin app!

Resources

https://gateway-api.sigs.k8s.io/