Introduction to events

This is my first presentation about event streamming/sourcing/DDD.

Steps

1. Start kafka in docker

   docker-compose -f events/resources/kafka/docker-compose.yml up -d
   

2. Build the binary

   go build -o events
   

3. Start http server accepting account creation

   ./events init --kafka-address localhost:9092 --output-topic accounts
   

4. We are going to assume all account related events will be published in accounts topic. One topic can store many types of events as long as they are going to be wrapped in Envelope event type where payload will be strictly related event type.

5. Make http request which will store data in database (badger in this case) and publish this data to the init-requests topic for further processing or data availability by other domains so they dont have to query the database each time.

   curl -XPOST -H "Content-Type: application/json" localhost:8080/create -d "{\"name\": \"gopher\", \"password\": \"v3ry-s3cr3t\"}"
   

6. Start a consumer that consumes from init-requests topic and publishes AccountCreatedEvent to accounts topic.

   ./events process --kafka-address localhost:9092 --input-topic init --output-topic accounts
   

7. Start a consumer that consumes from accounts topic and publishes many different events to the same topic.

   ./events process --kafka-address localhost:9092 --input-topic accounts --output-topic accounts
   

Protos

    make -C events proto