Configure Request Mirroring
Learn how to mirror your HTTP or gRPC traffic using NGINX Gateway Fabric.
HTTPRoute and GRPCRoute filters can be used to configure request mirroring. Mirroring copies a request to another backend.
In this guide, we will set up two applications, coffee and tea, and mirror requests between them. All requests sent to the coffee application will also be sent to the tea application automatically.
- Install NGINX Gateway Fabric.
Create the coffee and tea applications in Kubernetes by copying and pasting the following block into your terminal:
kubectl apply -f - <<EOF apiVersion: apps/v1 kind: Deployment metadata: name: coffee spec: replicas: 1 selector: matchLabels: app: coffee template: metadata: labels: app: coffee spec: containers: - name: coffee image: nginxdemos/nginx-hello:plain-text ports: - containerPort: 8080 --- apiVersion: v1 kind: Service metadata: name: coffee spec: ports: - port: 80 targetPort: 8080 protocol: TCP name: http selector: app: coffee --- apiVersion: apps/v1 kind: Deployment metadata: name: tea spec: replicas: 1 selector: matchLabels: app: tea template: metadata: labels: app: tea spec: containers: - name: tea image: nginxdemos/nginx-hello:plain-text ports: - containerPort: 8080 --- apiVersion: v1 kind: Service metadata: name: tea spec: ports: - port: 80 targetPort: 8080 protocol: TCP name: http selector: app: tea EOFRun the following command to verify the resources were created:
kubectl get pods,svcYour output should include the pods and services for coffee and tea:
NAME READY STATUS RESTARTS AGE pod/coffee-676c9f8944-dxvkt 0/1 ContainerCreating 0 3s pod/tea-6fbfdcb95d-xl22n 0/1 ContainerCreating 0 3s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/coffee ClusterIP 10.96.151.184 <none> 80/TCP 3s service/tea ClusterIP 10.96.185.235 <none> 80/TCP 3sFirst, create the cafe Gateway resource:
kubectl apply -f - <<EOF apiVersion: gateway.networking.k8s.io/v1 kind: Gateway metadata: name: cafe spec: gatewayClassName: nginx listeners: - name: http port: 80 protocol: HTTP EOFAfter creating the Gateway resource, NGINX Gateway Fabric will provision an NGINX Pod and Service fronting it to route traffic.
Save the public IP address and port of the NGINX Service into shell variables:
GW_IP=XXX.YYY.ZZZ.III GW_PORT=<port number>In a production environment, you should have a DNS record for the external IP address that is exposed, and it should refer to the hostname that the gateway will forward for.
Now create an HTTPRoute that defines a RequestMirror filter that copies all requests sent to /coffee to be sent to the coffee backend and mirrored to the tea backend. Use the following command:
kubectl apply -f - <<EOF apiVersion: gateway.networking.k8s.io/v1 kind: HTTPRoute metadata: name: mirror spec: parentRefs: - name: cafe sectionName: http hostnames: - "cafe.example.com" rules: - matches: - path: type: PathPrefix value: /coffee filters: - type: RequestMirror requestMirror: backendRef: name: tea port: 80 backendRefs: - name: coffee port: 80 EOFTest the configuration:
You can send traffic using the external IP address and port saved earlier:
curl --resolve cafe.example.com:$GW_PORT:$GW_IP http://cafe.example.com:$GW_PORT/coffeeThis request should receive a response from the coffee Pod:
Server address: 10.244.0.13:8080 Server name: coffee-676c9f8944-dxvktNow, check the logs of the tea application:
kubectl logs deployments/teaYou should see a log that looks similar to the following:
10.244.0.12 - - [17/Apr/2025:18:44:21 +0000] "GET /coffee HTTP/1.1" 200 158 "-" "curl/8.7.1" "127.0.0.1"This shows that the request to /coffee was mirrored to the tea application.
To learn more about request mirroring using the Gateway API, see the following resource: