Networking

OSI Model

DNS

mDNS

Ethernet

MAC Address

IP Address

Ports

Sockets

Packets

Practice Problems

Problem 1: Chat Application

In Python, implement a chat application (server and client) that allows users to send messages in a common chat room.

note

Fork the chat application repository and clone it to your local machine.

You will be working in a team setup, so make sure to coordinate with your team members. One fork per team. Each team member should be working on a separate branch.

Requirements

• The server should be able to handle multiple clients at once.

• The server should broadcast messages to all clients.

• The server should send a message to the chatroom when a new client joins the chat room.

• The server should send a message to the chatroom when a client leaves the chat room.

• The client should be able to send messages to the server.

• The client should be able to receive messages from the server.

• The client should be able to gracefully exit the chat room.

• The client should have a username, which is sent to the server when the client joins the chat room.

• The server should keep track of all clients in the chat room.

• The client is defined by:

  • username
  • IP address
  • password
  • unique ID

• The server is defined by:

  • IP address
  • port

• A message in the chat room is defined by:

  • sender (the client ID)
  • payload (the message)
  • timestamp
  • chatroom ID
  • unique ID

• The chat room is defined by:

  • name
  • unique ID

Hints

Here's a class diagram to help you get started:

You should at least have the following files:

• chat_server.py This is the main file that runs the server.
• chat_client.py This is the main file that runs the client.
• client.py This is the client class.
• server.py This is the server class.
• message.py This is the message class.
• chatroom.py This is the chatroom class.

Here's a sequence diagram to help you get started: