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Every BackAnt project ships with a Dockerfile, a development docker-compose.yml, a production docker-compose-prod.yml, and a GitHub Actions workflow for pushing images to Amazon ECR.

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Local development

Start the full stack (PostgreSQL + Flask) from the project root: 
docker-compose up --build
This starts:
  • PostgreSQL 16 on localhost:5432
  • Flask (gunicorn) on localhost:5000 with 4 workers
On first start, init_db() creates all tables automatically. Test the default route: 
curl http://localhost:5000/
# "Your backant backend is working"
To stop without removing volumes: 
docker-compose down

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Dockerfile

The generated Dockerfile uses python:3.11-slim-buster and runs Flask via gunicorn with 4 gthread workers: 
FROM python:3.11-slim-buster

ENV POSTGRES_USER=postgres \
    POSTGRES_PASSWORD=test \
    POSTGRES_DB=postgres \
    DB_URL=postgres \
    CLEAR_DB=True \
    FLASK_APP=app.py \
    FLASK_ENV=development

WORKDIR /app
COPY requirements.txt requirements.txt
RUN pip3 install -r requirements.txt
COPY api .

CMD [ "gunicorn", "--log-level", "debug", "--timeout", "0", \
      "-k", "gthread", "--workers", "4", "--bind", "0.0.0.0:5000", \
      "app:create_app()" ]
The ENV defaults in the Dockerfile are overridden at runtime by the environment variables in docker-compose.yml. Always configure sensitive values via .env, not the Dockerfile.

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Environment variables at runtime

docker-compose.yml injects all variables from your .env file into the container: 
flask_backend:
  build: .
  environment:
    POSTGRES_USER: ${POSTGRES_USER}
    POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
    POSTGRES_DB: ${POSTGRES_DB}
    DB_URL: ${DB_URL}
    CLEAR_DB: ${CLEAR_DB}
    FLASK_APP: ${FLASK_APP}
    FLASK_ENV: ${FLASK_ENV}
Ensure your .env at the project root has all required values set before running docker-compose up.

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Production deployment

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1. Set CLEAR_DB to False

CLEAR_DB=False
Never drop tables in production.

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2. Push to Amazon ECR via GitHub Actions

The generated workflow at .github/workflows/build_and_push_to_ecr.yml triggers on every push to main and:
  1. Configures AWS credentials via OIDC (no long-lived keys)
  2. Logs in to ECR
  3. Builds the Docker image
  4. Tags and pushes it to your ECR repository
Configure these values in the workflow file: 
env:
  AWS_REGION: eu-central-1
  ECR_REPOSITORY: your-repo-name
  TAG: latest
The workflow uses aws-actions/configure-aws-credentials@v4 with an IAM role assumed via GitHub’s OIDC provider. Set the role ARN in your workflow: 
role-to-assume: arn:aws:iam::<account-id>:role/GitHubAction-AssumeRoleWithAction

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3. Deploy with the production compose file

Update docker-compose-prod.yml with your ECR image URL: 
services:
  flask_backend:
    image: <account>.dkr.ecr.<region>.amazonaws.com/<repo>:latest
    environment:
      POSTGRES_USER: ${POSTGRES_USER}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
      POSTGRES_DB: ${POSTGRES_DB}
      DB_URL: ${DB_URL}
      CLEAR_DB: False
    ports:
      - "5000:5000"
    restart: always
Then deploy: 
docker-compose -f docker-compose-prod.yml up -d
The production compose file does not include the postgres service — use a managed database (e.g. AWS RDS) in production and point DB_URL at its hostname.