Kafka-Chat

Introduction

This is a sample application to test some technologies, different tools and frameworks.

The rough architecture is:

Angular ----- Spring Boot ----- Kafka / Zookeeper
                  |
                  |
                Redis

• Angular Frontend renders the view (messages are sent via websockets)
• Kafka stores and distributes the chat messages
• Redis stores the state of the chat rooms
• Spring boot glues it all together

Some Useful commands

Project specific

Starting the frontend

ng serve

Start Redis and Kafka via the script (the kafka installation folder needs to be adjusted)

scripts/start_kafka.bat

System API

List all chatrooms

curl  http://localhost:8080/api/room

Get all messages from a chatroom

curl  http://localhost:8080/api/room/[chatroom name]

Post a message

curl -H "Content-Type: application/json" -X POST -d '{"text":"[message text]", "user":"[user name]"}' http://localhost:8080/room/[chatroom name]/message

Kafka specific

create a new kafka topic

kafka-topics.bat --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic [topic name]

listen to incoming messages in the conolse

kafka-console-consumer.bat --bootstrap-server localhost:9092 --from-beginning --topic [topic name]

open a new producer from the console

kafka-console-producer.bat --broker-list localhost:9092 --topic [topic name]

get a description of a topic

kafka-topics.bat --describe --zookeeper localhost:2181 --topic [topic name]