Wetty Echo Server

Introduction

This docker container is created for demo purposes. It contains a TCP, UDP and HTTP based echo server and provides Web based terminal access into the container. The 4 different services offered, can be enabled or disabled at preference. The contiainer is based on Alpine Linux and has two flavors: a slim version without extra debug tools and a fat version with debug tools.

This container is useful for demoing and or debugging service mesh or other intra service network communication scenario's, without having to deploy a full blown microservice based application. The container can act both as the client (netcat for tcp/udp/http or curl for http) and a server. The servers are written in Javascript.

The web based terminal is based on wetty. A user account admin with password admin has been created for terminal access.

In order to provide proper container support for multiple processes running, dumb-init is used as a simple process supervisor and init system designed to run as PID 1 inside minimal container.

Github & dockerhub

The source code and docker containers are available at the following locations.

Github: https://github.com/boeboe/wetty-echo-server
Dockerhub: https://hub.docker.com/r/boeboe/wetty-echo-server

Usage

Environment variables

The following docker ENV variables can be used to tweak the behavior of this container.

ENV Variable	Default	Usage
WETTY_ENABLED	true	enable web terminal
WETTY_PORT	3000	web terminal port
TCP_ECHO_ENABLED	true	enable tcp echo server
TCP_ECHO_HOST	0.0.0.0	tcp echo server host
TCP_ECHO_PORT	3001	tcp echo server port
UDP_ECHO_ENABLED	true	enable udp echo server
UDP_ECHO_HOST	0.0.0.0	udp echo server host
UDP_ECHO_PORT	3002	udp echo server port
HTTP_ECHO_ENABLED	true	enable http echo server
HTTP_ECHO_HOST	0.0.0.0	http echo server host
HTTP_ECHO_PORT	3003	http echo server port

Docker run

In order to run this container with the defaults (all services enabled):

$ docker run -i -t --rm -p=18080:3000 -p=18081:3001 -p=18082:3002/udp -p=18083:3003 --name="wetty-echo-server" boeboe/wetty-echo-server

To run the container with only wetty and http echo enabled:

$ docker run -i -t --rm -p=18080:3000 -p=18083:3003 -e TCP_ECHO_ENABLED=false -e UDP_ECHO_ENABLED=false --name="wetty-echo-server" boeboe/wetty-echo-server

Termanal usage

The user credentials for the web based terminal access method are:

username: admin
password: admin

The terminal is accessible on the following url:

url_terminal: http://<host>:18080/wetty

An example on on how to use the container as both client and server.

Installed tooling

There are two versions of this docker container. A slim and a fat version, the latter containing extra debugging and demo tooling.

Current version is 1.0.0.

Version tag	Tools installed
1.0.0	dumb-init openssh-client sshpass curl netcat-openbsd jq
1.0.0-dbg	bash tree vim nano strace iputils wget httpie net-tools socat tcpdump bind-tools iproute2 tcptraceroute iperf3

Extra Alpine packages can be installed on the fly with the package manager apk.

$ apk add -U zsh

Note

This container is purely used for demo purposes and not meant for production environments at all.

boeboe / wetty-echoserver