Automating Flask Deployment with GitHub Actions and Docker

Introduction Continuous Integration and Continuous Deployment (CI/CD) are essential for modern software development. In this tutorial, I will walk you through setting up a CI/CD pipeline for a Flask application using GitHub Actions and Docker. By the end of this guide, you will have an automated workflow that builds, tests, and pushes a Docker image to Docker Hub. Prerequisites Before we get started, ensure you have the following: Python 3.x installed on your machine. Docker installed and configured. A GitHub repository for your Flask project. A Docker Hub account to store container images. Step 1: Setting Up the Flask Application Let's start by creating a simple Flask application. Create a project directory: mkdir flask-cicd && cd flask-cicd Create a virtual environment and activate it: python3 -m venv venv source venv/bin/activate # On macOS/Linux venv\Scripts\activate # On Windows Install Flask: pip install flask Create an app.py file: from flask import Flask app = Flask(name) @app.route('/') def home(): return "Hello, Flask CI/CD!" if name == 'main': app.run(host='0.0.0.0', port=5000) Create a requirements.txt file: flask Step 2: Dockerizing the Flask Application Create a Dockerfile in the project directory: # Use official Python image FROM python:3.10 WORKDIR /app COPY requirements.txt requirements.txt RUN pip install --no-cache-dir -r requirements.txt COPY . . EXPOSE 5000 CMD ["python", "app.py"] To test the Docker container locally, build and run it: docker build -t flask-cicd . docker run -p 5000:5000 flask-cicd Step 3: Setting Up GitHub Actions for CI/CD Now, we will create a GitHub Actions workflow to automate building and pushing our Docker image to Docker Hub. Inside your project, create .github/workflows/main.yml and add the following: name: Flask CI/CD on: push: branches: [ "main" ] pull_request: branches: [ "main" ] permissions: contents: read jobs: build: runs-on: ubuntu-latest steps: - name: Checkout Repository uses: actions/checkout@v4 - name: Set up Python 3.10 uses: actions/setup-python@v3 with: python-version: "3.10" - name: Install Dependencies run: | python -m pip install --upgrade pip pip install flake8 pytest if [ -f requirements.txt ]; then pip install -r requirements.txt; fi - name: Lint with flake8 run: | flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics - name: Log in to Docker Hub uses: docker/login-action@v3 with: username: ${{ secrets.DOCKER_USERNAME }} password: ${{ secrets.DOCKER_PASSWORD }} - name: Set up Docker Buildx uses: docker/setup-buildx-action@v3 - name: Build and Push Docker Image uses: docker/build-push-action@v5 with: context: . file: Dockerfile push: true tags: ${{ secrets.DOCKER_USERNAME }}/flask-app:latest Also, remember to create a .gitignore file and .dockerignore file. Step 4: Configuring GitHub Secrets To securely authenticate with Docker Hub, add the following GitHub Secrets in your repository: DOCKER_USERNAME: Your Docker Hub username. DOCKER_PASSWORD: Your Docker Hub password. Step 5: Pushing Code and Running the Pipeline Now, push your code to GitHub: git init git add . git commit -m "Initial commit" git branch -M main git remote add origin git push -u origin main Once pushed, GitHub Actions will automatically run the workflow. You can check the status under the Actions tab in your repository. Conclusion Congratulations!

Apr 1, 2025 - 10:34

Automating Flask Deployment with GitHub Actions and Docker

Introduction

Continuous Integration and Continuous Deployment (CI/CD) are essential for modern software development. In this tutorial, I will walk you through setting up a CI/CD pipeline for a Flask application using GitHub Actions and Docker. By the end of this guide, you will have an automated workflow that builds, tests, and pushes a Docker image to Docker Hub.

Prerequisites

Before we get started, ensure you have the following:

Python 3.x installed on your machine.
Docker installed and configured.
A GitHub repository for your Flask project.
A Docker Hub account to store container images.

Step 1: Setting Up the Flask Application

Let's start by creating a simple Flask application.

Create a project directory:
```
mkdir flask-cicd && cd flask-cicd
```

Create a virtual environment and activate it:

python3 -m venv venv
source venv/bin/activate  # On macOS/Linux
venv\Scripts\activate  # On Windows

Install Flask:
```
pip install flask
```

Create an app.py file:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def home():
    return "Hello, Flask CI/CD!"

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)

Create a requirements.txt file:
```
flask
```

Step 2: Dockerizing the Flask Application

Create a Dockerfile in the project directory:

# Use official Python image
FROM python:3.10

WORKDIR /app

COPY requirements.txt requirements.txt
RUN pip install --no-cache-dir -r requirements.txt

COPY . .
EXPOSE 5000
CMD ["python", "app.py"]

To test the Docker container locally, build and run it:

docker build -t flask-cicd .
docker run -p 5000:5000 flask-cicd

Step 3: Setting Up GitHub Actions for CI/CD

Now, we will create a GitHub Actions workflow to automate building and pushing our Docker image to Docker Hub.

Inside your project, create .github/workflows/main.yml and add the following:

name: Flask CI/CD

on:
  push:
    branches: [ "main" ]
  pull_request:
    branches: [ "main" ]

permissions:
  contents: read

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout Repository
        uses: actions/checkout@v4

      - name: Set up Python 3.10
        uses: actions/setup-python@v3
        with:
          python-version: "3.10"

      - name: Install Dependencies
        run: |
          python -m pip install --upgrade pip
          pip install flake8 pytest
          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi

      - name: Lint with flake8
        run: |
          flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
          flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics

      - name: Log in to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Build and Push Docker Image
        uses: docker/build-push-action@v5
        with:
          context: .
          file: Dockerfile
          push: true
          tags: ${{ secrets.DOCKER_USERNAME }}/flask-app:latest

Also, remember to create a .gitignore file and .dockerignore file.

Step 4: Configuring GitHub Secrets

To securely authenticate with Docker Hub, add the following GitHub Secrets in your repository:

DOCKER_USERNAME: Your Docker Hub username.
DOCKER_PASSWORD: Your Docker Hub password.

Step 5: Pushing Code and Running the Pipeline

Now, push your code to GitHub:

git init
git add .
git commit -m "Initial commit"
git branch -M main
git remote add origin 
git push -u origin main

Once pushed, GitHub Actions will automatically run the workflow. You can check the status under the Actions tab in your repository.

Conclusion

Congratulations!