starterapp

This is an attempt to come up with a modular application architecture in Go. The application makes use of my command bus implementation. The idea being that the application/command bus struct can be passed to several modules and they can plug themselves in.

Goal

The primary goal of this is to create a client agnostic application. The client could be an http server, CLI client, or anything else that can take input, create command structs, and pass them to the application to be handled.

Structure

The meat of the application lives in /app. The application modules live there. There is only one domain module so far, user. The application is created in /app/app.go and is passed to the user module to be connected in /app/user/app.go.

Currently there only two commands/handlers, a RegisterUserCommand and FindUserByIdCommand. They live in app/user/command.go.

HTTP Server Client

There is only one client to the application, the http server. It takes the same modular approach. The application and http router are created in /httpserver/main.go. They are then passed to the user module in /httpserver/user/user.go to register the http routes to http handlers that are responsible for creating command structs, passing them to the application/command bus to be handled, then writing a response to the http.ResponseWriter.

The http server application relies on a yml configuration file to keep sensitive configuration data. It looks like this:

# /config/starterapp.yml

database_user:     go_app
database_password: s3cr3t123
database_host:     localhost
database_port:     5432
database_name:     startapp_dev

The http server currently has two endpoints. One to register a user:

POST /register

{
    "user": {
        "username": "johndoe",
        "email": "jdoe@example.org",
        "password": "s3cr3t123"
    }
}

Response - 201

{
    "user": {
        "created_at": 1431397823,
        "email": "jdoe@example.org",
        "enabled": false,
        "id": "615164bc-8129-468d-5c11-f6b352dc740e",
        "username": "johndoe"
    }
}

The other endpoint is to retrieve an already registered user:

GET /user/{id}

Response - 200

{
    "user": {
        "created_at": 1431397823,
        "email": "jdoe@example.org",
        "enabled": false,
        "id": "615164bc-8129-468d-5c11-f6b352dc740e",
        "username": "johndoe"
    }
}

I'm planning on tackling a CLI client next.