GO (TCP) Echo

A Simple go TCP echo server. Written to learn and test Kubernetes TCP networking.

Test with Docker

Run the container from a terminal:

docker run --rm -it -e TCP_PORT=2701 -e NODE_NAME="EchoNode" -p 2701:2701 cjimti/go-echo

In another terminal run:

telnet localhost 2701

Test with Kubernetes

cd k8s
kubectl create -f . 

You should now have two TCP echo containers running:

kubectl get pods --selector=app=tcp-echo

NAME                                   READY     STATUS    RESTARTS   AGE
tcp-echo-deployment-777d856787-5fhb4   1/1       Running   0          27s
tcp-echo-deployment-777d856787-rh9tp   1/1       Running   0          27s

You should also have a service that connection port 32701 to the pods:

kubectl get service --selector=app=tcp-echo-service

NAME               TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
tcp-echo-service   NodePort   10.102.207.113   <none>        2701:32701/TCP   35m

Echo some data, replace ANY_NODE_IP with a location of a node:

telnet ANY_NODE_IP 32701

After connecting, type the word hello and hit return:

Trying x.x.x.x...
Connected to node1.example.com.
Escape character is '^]'.
Welcome, you are connected to node node1.example.com.
Running on Pod tcp-echo-deployment-777d856787-rh9tp.
In namespace default.
With IP address 192.168.33.39.
Service default.
hello
hello

Resources

• Expose Pod Information to Containers Through Environment Variables
• Docker
• Kubernetes