NOTE: I have created client image, and it does connects, but for some reason I am not able to send anything via that connection. It possible only when I am running netcat via bash image.

1. Create network

docker network create test_network

2. Build images

Server

$ cd server/
$ sudo docker build -t netcat-server .

Client

$ cd server/
$ sudo docker build -t netcat-client .

3. Run server

docker container run -p 5959:5959 --network test_network  netcat-server 5959
#in detached mode. (choice)
docker container run -d -p 5959:5959  --network test_network netcat-server
docker container -f <container hash>

4. Find out Server IP

#see in "Containers chapter"
docker network inspect test_network
# or
docker container inspect <container-name>

Run client (only connection)

docker container run -it --network test_network  netcat-client <IP address> <PORT>

Run client(with message being sent)

$ docker run -it --network test_network bash
# in bash(in container), we are running
$ echo "Hello!" | nc -v <ip-address> <port>