# kafka-demo
This project is just a sample demonstration inspired by question "How do
we monitor a kafka stream with a OneAgent and see the data on Dynatrace?"

# setup
You need to [download](https://kafka.apache.org/downloads) kafka on your
device. For this demo project the binary Scala 2.12 - kafka_2.12-3.5.1.tgz
was downloaded, therefore kafka version 3.5.1 is used.

# run
First you have to start and run the zookeeper server, afterwards the kafka server
and finally the consumers.
```shell
bin/zookeeper-server-start.sh config/zookeeper.properties
bin/kafka-server-start.sh config/server.properties
bin/kafka-console-consumer.sh --topic TOPIC_INSTANCE --from-beginning --bootstrap-server localhost:9092
bin/kafka-console-consumer.sh --topic TOPIC_INSTANCE_JSON --from-beginning --bootstrap-server localhost:9092
```
`NOTE: MAKE SURE YOU FOLLOW THE ORDER!`

Run this project by starting the KafkaDemoApplication!

# demo
Once everything is running open the following link in your browser:
http://localhost:8080/api/v1/kafka/publish

If you want to produce a message then you can add the message query parameter and
your value as following:
http://localhost:8080/api/v1/kafka/publish?message=Madrid
http://localhost:8080/api/v1/kafka/publish?message=London
http://localhost:8080/api/v1/kafka/publish?=Vienna
http://localhost:8080/api/v1/kafka/publish?=Pizza

On one of the consumers you will see the messages!

It is possible to send a JSON Object. To do that you will have to send a POST
request via e.g. Postman. In Postman choose the POST method and use this link:
http://localhost:8080/api/v1/kafka/publish

Afterward under Body, pick raw and instead Text pick JSON. In the body section
you can add the following object:
```JSON
{
    "id": 1,
    "vin": "V09JHY4",
    "location": "New York" 
}
```
Send.

You should be able to see the data in one of the consumers! If you encounter
any warnings after starting the consumers you can ignore them!