UDP Routing
The UDPRoute provides a method to route UDP traffic. When combined with a gateway listener, it can be used to forward traffic on a port specified by the listener to a set of backends defined in the UDPRoute.
Prerequisites
- Kubernetes cluster version v1.21.0 or higher.
- kubectl CLI
- FSM Gateway installed via guide doc.
Demonstration
Prerequisites
- Kubernetes cluster
- kubectl tool
Environment Setup
Deploying Sample Application
Use fortio server as a sample application, which provides a UDP service listening on port 8078 and echoes back the content sent by the client.
kubectl create namespace server
kubectl apply -n server -f - <<EOF
apiVersion: v1
kind: Service
metadata:
name: fortio
labels:
app: fortio
service: fortio
spec:
ports:
- port: 8078
name: udp-8078
selector:
app: fortio
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: fortio
spec:
replicas: 1
selector:
matchLabels:
app: fortio
template:
metadata:
labels:
app: fortio
spec:
containers:
- name: fortio
image: fortio/fortio:latest_release
imagePullPolicy: Always
ports:
- containerPort: 8078
name: http
EOF
Creating UDP Gateway
Next, create a Gateway for the UDP service, setting the protocol of the listening port to UDP.
kubectl apply -n server -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
namespace: server
name: simple-fsm-gateway
spec:
gatewayClassName: fsm-gateway-cls
listeners:
- protocol: UDP
port: 8000
name: udp
EOF
Creating UDP Route
Similar to the HTTP protocol, to access backend services through the gateway, a UDPRoute needs to be created.
kubectl -n server apply -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: UDPRoute
metadata:
name: udp-route-sample
spec:
parentRefs:
- name: simple-fsm-gateway
namespace: server
port: 8000
rules:
- backendRefs:
- name: fortio
port: 8078
EOF
Test accessing the UDP service. After sending the word ‘fsm’, the same word will be received back.
export GATEWAY_IP=$(kubectl get svc -n server -l app=fsm-gateway -o jsonpath='{.items[0].status.loadBalancer.ingress[0].ip}')
echo 'fsm' | nc -4u -w1 $GATEWAY_IP 8000
fsm
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