Example

In this example we will deploy NGINX Gateway Fabric and configure traffic splitting for a simple cafe application. We will use HTTPRoute resources to split traffic between two versions of the application -- coffee-v1 and coffee-v2.

Running the Example

1. Deploy NGINX Gateway Fabric

1. Follow the installation instructions to deploy NGINX Gateway Fabric.

2. Save the public IP address of NGINX Gateway Fabric into a shell variable:

   GW_IP=XXX.YYY.ZZZ.III
   

3. Save the port of NGINX Gateway Fabric:

   GW_PORT=<port number>
   

2. Deploy the Coffee Application

1. Create the Cafe Deployments and Services:

   kubectl apply -f cafe.yaml

2. Check that the Pods are running in the default Namespace:

   kubectl -n default get pods

   NAME                         READY   STATUS    RESTARTS   AGE
   coffee-v1-7c57c576b-rfjsh    1/1     Running   0          21m
   coffee-v2-698f66dc46-vcb6r   1/1     Running   0          21m
   

3. Configure Routing

1. Create the Gateway:

   kubectl apply -f gateway.yaml

2. Create the HTTPRoute resources:

   kubectl apply -f cafe-route.yaml

This HTTPRoute resource defines a route for the path /coffee that sends 80% of the requests to coffee-v1 and 20% to coffee-v2. In this example, we use 80 and 20; however, the weights are calculated proportionally and do not need to sum to 100. For example, the weights of 8 and 2, 16 and 4, or 32 and 8 all evaluate to the same relative proportions.

4. Test the Application

To access the application, we will use curl to send requests to /coffee:

curl --resolve cafe.example.com:$GW_PORT:$GW_IP http://cafe.example.com:$GW_PORT/coffee

80% of the responses will come from coffee-v1:

Server address: 10.12.0.18:80
Server name: coffee-v1-7c57c576b-rfjsh

20% of the responses will come from coffee-v2:

Server address: 10.12.0.19:80
Server name: coffee-v2-698f66dc46-vcb6r

5. Modify the Traffic Split Configuration

Let's shift more of the traffic to coffee-v2. To do this we will update the HTTPRoute resource and change the weight of the coffee-v2 backend to 80. Backends with equal weights will receive an equal share of traffic.

1. Apply the updated HTTPRoute resource:

   kubectl apply -f cafe-route-equal-weight.yaml

2. Test the application again:

   curl --resolve cafe.example.com:$GW_PORT:$GW_IP http://cafe.example.com:$GW_PORT/coffee

The responses will now be split evenly between coffee-v1 and coffee-v2.

We can continue modifying the weights of the backends to shift more and more traffic to coffee-v2. If there's an issue with coffee-v2, we can quickly shift traffic back to coffee-v1.