🐳 Docker RL Lab

This repo contains the source files for the docker images required in the Docker RL laboratory.

🧱 Prerequisites

In order to be able to run and build this repository, you will need the following packages:

• Python 3
• NodeJS > 12
• Docker

👨‍💻 Development steps

This section will go over the rough steps needed to run the local development environment for each project. For more details, check the README files in the respective project's folder.

🎨 Frontend app

The frontend application is a Create React App application, so most of the documentation there also applies here.

In order to spin up the development server, run the following commands:

cd docker-app/frontend-context
yarn # or npm install - To install required packages
yarn start # or npm start - To spin up the development server

# Run frontend in container
cd frontend-context/
yarn build
docker build -t rl-frontend-image .

docker run -d --name=rl-frontend --hostname=rl-frontend \
    -e FRONTEND_NODE=FIRST_NODE \
    -e BACKEND_SERVER=192.168.200.3 \
    -p 80:80 --network=rl-network \
    --ip=192.168.200.2 \
    rl-frontend-image

The frontend development server will run on localhost:3000. It will also expect the backend server to be up and running on localhost:5000.

📦 Database

The database is a MySQL Docker container that you have to turn on before running the API. To spin it up, run the following commands:

cd database-context/
docker run -d --name=rl-database --hostname=rl-database \
    -e MYSQL_DATABASE=rl-database \
    -e MYSQL_USER=rl-user \
    -e MYSQL_PASSWORD=rl-specialpassword \
    -e MYSQL_ROOT_PASSWORD=root \
    -e TZ=Europe/Bucharest \
    -p 3306:3306 \
    --network=rl-network \
    --ip=192.168.200.4 \
    rl-database-image

You can also follow logs to know when the database has finished spinning up:

docker logs -f rl-database

🚚 Backend API

The backend API is a Flask project written in Python 3. In order to turn it on, you have to do the following:

cd docker-app/backend-context
flask db init # This will configure a fresh database
flask db migrate #
flask db upgrade # This will sync up the database with the ORM models

python3 init_db.py # Insert initial data about the predefined images

python3 run.py # Start the application

In the case that you are running a previous version of the database and need to bring it up to the most recent version, you can run the following command to execute the migrations:

flask db migrate

🚛 Deployment steps

Deployment is done via Docker Hub and is automatically done on every push to the master branch via GitHub Actions.

If you want to build the images locally, you have to follow certain steps for each component of the application:

🎨 Frontend

The frontend application needs to first be built, and the resulting files need to be delivered via a static web server such as Nginx.

In order to build the frontend application, run the following commands:

cd docker-app/frontend-context
yarn # or npm install - to install files
yarn build # or npm run build

This will generate a build/ folder which contains all the assets that need to be delivered to the end user. A sample nginx configuration is also provided in docker-app/frontend-context/util/nginx/site.

📦 Database

There is one schema in the database named images that is created at deployment using SQLAlchemy ORM. Database connection details such as server name, username, password are retrieved from environment variables defined at start-up.

cd database-context/
docker run -d --name=rl-database --hostname=rl-database \
    -e MYSQL_DATABASE=rl-database \
    -e MYSQL_USER=rl-user \
    -e MYSQL_PASSWORD=rl-specialpassword \
    -e MYSQL_ROOT_PASSWORD=root \
    -e TZ=Europe/Bucharest \
    -p 3306:3306 \
    --network=rl-network \
    --ip=192.168.200.4 \
    rl-database-image

🚚 Backend API

The entire logic (incuding the database Models) resides in run.py script.

In backend-context the entrypoint script init.sh:

• install the Python packages,
• apply the migrations,
• run the init_db.py that adds default entries in the database
• and in the end it starts the application.

cd backend-context/
docker build -t rl-backend-image .
docker run -d --name=rl-backend --hostname=rl-backend \
    -e DB_SERVER=192.168.200.4 \
    -p 5000:5000 --network=rl-network \
    --ip=192.168.200.3 \
    rl-backend-image