Messaging App Backend with Flask and PostgreSQL DB

Working locally

Clone this repo on your machine

To clone the repo, run the following command:

git clone https://github.com/VladChira/ip-messaging-server.git

You will be asked to enter your credentials. For the password, you must enter a Personal Access Token instead of your account password. Click here to learn how to create a token.

Installing dependencies

You will need python installed system-wide and docker. The other dependencies will be installed in a virtual environment.

If you are on Ubuntu, the easiest way to install Docker is using the convenience script here. For other distros/operating system, please refer to the Docker docs.

Creating a branch

Create a new branch using git branch <branch name> and switch to it with git checkout <branch name>. Here is where you will work on features. When ready to merge to main, push to the branch and submit a pull request.

Creating a virtual environment

For better isolation, python packages will not be installed globally, but in a virtual environment instead. Create one in root of the project with python3 -m venv venv then activate it with source venv/bin/activate.

To install the necessary packages, run pip install -r requirements.txt.

If during development you find yourself installing other packages, add them to the requirements.txt file using pip freeze > requirements.txt

Injecting secrets

Sensitive information cannot be stored in the github repo, such as the postgresql username and password. These secrets will be injected into the app at runtime using the dotenv package. Create a file in the root of the project called .env and ask Vlad for the secrets. The .env file is automatically gitignored.

Running the database container

The postgresql database will be run in a Docker container. A script to launch the database has been provided: run_db_local.sh, as well as a script to test the database connection with the injected secrets: test_db_conn.py.

To look at logs/errors, run sudo docker logs chatapp-db -f.

To stop the db, run sudo docker stop chatapp-db. To remove the db, run sudo docker rm chatapp-db after stopping the container.

Running the Flask app

In development mode, there is no reason to run the Flask app in a container. Run python3 run.py to launch the Flask app. The app will run on the port specified in the run.py file (i.e. 5000).

Schema migrations

TODO

Deploying to production

In production, both the Flask backend and the database will be run in containers.

To deploy your code to production, submit a pull request. After it's merged to the main branch, a Github workflow will automatically deploy the backend to the server.

Please do not touch the Dockerfile and the docker-compose.yml files. They are meant for production setup.

You may review the workflow that deploys this app in the .github/workflows folder and/or ask Vlad for more info.