Event Sourcing with pure Kotlin example

The goal of this project is to show a sample of event sourcing implementation with pure Kotlin, with the minimum of frameworks.

Tech stack

• Gradle
• Kotlin
• Javalin
• Koin
• MongoDB
• Spek Framework

Running

In order to get the project running, you need to:

• Provide the following environment vars:

SERVER_PORT     7000
MONGO_HOST      localhost 
MONGO_PORT      27017
MONGO_USER      mongo
MONGO_PASS      password
MONGO_DATABASE  admin

• Provide a running MongoDB instance that correspond to the configured vars. You can use Docker, for example:

$ docker container run 
                        -e MONGO_INITDB_ROOT_USERNAME=mongo \
                        -e MONGO_INITDB_ROOT_PASSWORD=mongo \
                        -e MONGO_INITDB_DATABASE=credit_limit \ 
                        -p 127.0.0.1:27017:27017 \
                        --name credit_limit \
                        -d mongo

• Execute the application

$ gradle run

About the project

Features

In order to test some flows of event sourcing implementation, some features were implemented:

• Create a user: You can create a new user by giving its username:

[POST] /users

{
  "username": "userNameTest"
}

• Block a user: You can block and unblock a user by giving its block state:

[PATCH] /users

{
  "username": "userNameTest",
  "block": true
}