# TCP Echo Service

This sample runs [TCP Echo Server](src/) as an Istio service. TCP Echo Server
allows you to connect to it over TCP and echoes back data sent to it along with
a preconfigured prefix.

## Usage

To run the TCP Echo Service sample:

1. Install Istio by following the [istio install instructions](https://istio.io/docs/setup/kubernetes/quick-start.html).

1. Start the `tcp-echo-server` service inside the Istio service mesh:

    ```console
    $ kubectl apply -f <(istioctl kube-inject -f tcp-echo.yaml)
    service/tcp-echo created
    deployment.apps/tcp-echo created
    ```

1. Test by running the `nc` command from a `busybox` container from within the cluster.

    ```console
    $ kubectl run -i --rm --restart=Never dummy --image=busybox -- sh -c "echo world | nc tcp-echo 9000"
    hello world
    pod "dummy" deleted
    ```

    As you observe, sending _world_ on a TCP connection to the server results in
    the server prepending _hello_ and echoing back with _hello world_.

1. To clean up, execute the following command:

    ```console
    $ kubectl delete -f tcp-echo.yaml
    service "tcp-echo" deleted
    deployment.apps "tcp-echo" deleted
    ```