HNG DevOps Stage - 2

Introduction

As part of my HNG DevOps Internship, I was tasked with deploying a FastAPI application with a Continuous Integration (CI) and Continuous Deployment (CD) pipeline while ensuring the application is served using Nginx as a reverse proxy. This blog post will guide you step by step on how to complete this project.

Project Overview

In this task, we:

1. Implement a missing API endpoint.

2. Set up a CI pipeline to run tests using pytest.

3. Configure a CD pipeline to deploy on merging into main.

4. Dockerize the FastAPI application.

5. Serve the application using Nginx.

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Step 1: Fork the Template Repository

1. Navigate to the given template repository on GitHub.

2. Click on Fork to create a copy under your GitHub account.

3. Clone your forked repository to your local machine:

    git clone https://github.com/your-username/fastapi-project.git
    cd fastapi-project
   

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NOTE: THIS REPO IS NO LONGER UP.

Step 2: Implement the Missing Endpoint

We need to add an endpoint to retrieve a book by its ID.

Modify routes.py

1. Open the routes.py file.

2. Add the following function:

    from fastapi import FastAPI, HTTPException
    from models import books  # Assuming books is a predefined list or database object
   
    app = FastAPI()
   
    @app.get("/api/v1/books/{book_id}")
    async def get_book(book_id: int):
        book = next((book for book in books if book["id"] == book_id), None)
        if not book:
            raise HTTPException(status_code=404, detail="Book not found")
        return book
   

3. Save the file and test it locally using uvicorn:

    uvicorn main:app --reload
   

4. Open http://127.0.0.1:8000/docs to test the new endpoint.

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Step 3: Set Up the CI Pipeline

A CI pipeline will run tests automatically.

Create .github/workflows/ci.yml

1. Create a .github/workflows/ci.yml file with:

    name: CI
   
    on:
      pull_request:
        branches:
          - main
   
    jobs:
      test:
        runs-on: ubuntu-latest
        steps:
          - name: Checkout repository
            uses: actions/checkout@v3
          - name: Set up Python
            uses: actions/setup-python@v3
            with:
              python-version: "3.9"
          - name: Install dependencies
            run: |
              pip install -r requirements.txt
          - name: Run tests
            run: pytest
   

2. Commit and push this file.

3. Open a Pull Request and verify the test job runs successfully.

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Step 4: Set Up the Deployment Pipeline

Create .github/workflows/deploy.yml

1. Add a new file .github/workflows/deploy.yml:

    name: Deploy
   
    on:
      push:
        branches:
          - main
   
    jobs:
      deploy:
        runs-on: ubuntu-latest
        steps:
          - name: Checkout repository
            uses: actions/checkout@v3
          - name: Build and Push Docker Image
            run: |
              docker build -t my-fastapi-app .
              docker run -d -p 8000:8000 my-fastapi-app
   

2. Push changes and merge a PR to test deployment.

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Step 5: Dockerize the FastAPI App

Create Dockerfile

FROM python:3.9-slim
WORKDIR /app
COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt
COPY . .
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]

1. Build and test locally:

    docker build -t fastapi-app .
    docker run -p 8000:8000 fastapi-app
   

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Step 6: Set Up Nginx as a Reverse Proxy

Modify nginx.conf

1. Create nginx.conf:

    server {
        listen 80;
        server_name localhost;
   
        location / {
            proxy_pass http://127.0.0.1:8000;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }
    }
   

2. Run Nginx with Docker:

    docker run --name nginx -v $(pwd)/nginx.conf:/etc/nginx/nginx.conf:ro -p 80:80 nginx
   

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Step 7: Deploy the Application

1. Push the Docker image to a registry (e.g., Docker Hub, AWS ECR, GitHub Container Registry).

    docker tag fastapi-app your-username/fastapi-app:latest
    docker push your-username/fastapi-app:latest
   

2. Deploy to a cloud provider or a self-hosted server with Docker and Nginx configured.

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Conclusion

This project strengthened my CI/CD automation, Dockerization, and Nginx deployment skills.

I successfully:

1. Implemented a missing API endpoint

2. Set up a deployment pipeline.

3. Configured Nginx as a reverse proxy.

With each project I complete at HNG I learn a lot and I look forward to the next ones

#DevOps #FastAPI #Docker #GitHubActions #CI/CD #Nginx #CloudComputing