Simple Messaging API

Installation

The first step is to clone the repository.
Then, there are two options for starting the application: using a Docker environment or launching it manually as a uvicorn app from the command line.

Using Docker environment:

1. Make sure that you have Docker (and docker-compose) installed. See https://docs.docker.com/desktop/ for details.
2. If you're running a UNIX-based OS (Linux, macOS, FreeBSD, etc.) and it's your first run, execute the following script from the root directory of the project:

./build.sh

Then start it using the command below:

docker-compose up

The default port 8000 will be exposed to 9000 on localhost, and you can access the Swagger UI at http://localhost:9000/docs.

Alternatively, you can launch it on a host PC manually

To achieve this, you need to make the following steps:

1. Make sure that you have Python 3.9+ installed.
2. In the root directory of the app, execute the following CLI command to create a virtual environment:

python3 -m venv venv

3. Activate it. If you're running a UNIX-based OS, run:

source venv/bin/activate

If you're running Windows, run:

venv\Scripts\activate.bat

4. Install the requirements from the root directory:

pip3 install -r requirements.txt

5. Launch the application by running the command (you can choose any free port on your host):

python -m uvicorn messaging_api.main:app --host=localhost --port=9000 --reload

As in the previous setup option, you can then access it at http://localhost:9000/docs.

Running tests

1. In the case of running the application under the Docker environment, the tests will be launched in their own container before the application container, so you'll be able to see the test results in STDOUT.
2. If you're running the application locally, then just activate venv and execute the following command line to see the results:

pytest

Usage

In the default configuration, the Swagger UI for the API can be reached at http://localhost:9000/docs. The Messaging API provides basic authentication using headers.

All requests to its endpoints (except user registration) should contain "username" and "password" headers to gain access to the API.

There are four endpoints, which can be called using Swagger UI or Postman, according to the pattern http://localhost:9000/<URL PATH>/:

1. Create (register) a new user.

• URL path: /users/
• HTTP Method: POST
• Example of a JSON request payload: {"username": "john_doe", "password": "derpasswort"}
• After successful registration, these credentials can be used as authentication headers for all further requests.
• Authentication is not required.

2. Get a list of existing users.

• URL path: /users/
• HTTP Method: GET
• This endpoint supports basic (optional) limit/offset pagination which can be used as follows: http://127.0.0.1:8000/users/?skip=0&limit=100
• Authentication is required.

3. Create a message from a user.

• URL path: /users/{user_id}/messages/ where {user_id} is the ID of an existing user.
• HTTP Method: POST
• Creating messages on behalf of other users is not allowed.
• Authentication is required.

4. Get a list of messages.

• URL path: /messages/ or /messages/?user_id={user_id}
• HTTP Method: GET
• If user_id is provided, the endpoint will return messages for the given user; otherwise, all messages will be returned.
• Authentication is required.