I know that Gitub action is for CI/ CD but I need to deploy a model FastAPI application . I’m deploying a FastAPI application using GitHub Actions. The app is served with Uvicorn and exposed through Ngrok. Although the logs show that everything is running correctly and provide a public Ngrok URL, I am unable to access the application at the provided URL.

Configuration Details:

FastAPI App: Runs on Uvicorn at 0.0.0.0:8000.
Ngrok: Exposes the app to a public URL.
GitHub Actions: Orchestrates the setup, installation, and server running.

GitHub Actions Log Output:

Run uvicorn scripts.main:app --host 0.0.0.0 --port 8000 &
INFO: Started server process [2832]
INFO: Waiting for application startup.
INFO: Application startup complete.
INFO: Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
FastAPI app running at https://c3f3-20-161-78-239.ngrok-free.app

Firewall Settings:

Allowed TCP traffic on port 8000.
Issue:
The FastAPI app URL https://c3f3-20-161-78-239.ngrok-free.app is not accessible.

Questions:

Could the GitHub Actions environment be affecting the Ngrok tunnel’s stability or availability?
Are there any common pitfalls or configurations I might be missing that could prevent access to the Ngrok URL?
How can I ensure the Ngrok tunnel remains active and accessible as long as the GitHub Actions workflow is running?

my action yml file

name: Deploy FastAPI Application

on: 
  push:
    branches:
      - main  
  pull_request:
    branches:
      - main
  workflow_dispatch:  

jobs:
  train-and-deploy:
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v3

    - name: Set up Python
      uses: actions/setup-python@v4
      with:
        python-version: '3.10' 

    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip
        pip install -r requirements.txt

    - name: Train model
      run: python scripts/train_model.py
      env:
        PYTHONPATH: ${{ github.workspace }}

    - name: Public IP
      id: ip
      uses: haythem/[email protected]

    - name: Print Public IP
      run: |
        echo "Public IPv4: ${{ steps.ip.outputs.ipv4 }}"
        echo "Public IPv6: ${{ steps.ip.outputs.ipv6 }}"

    - name: Install Ngrok
      run: |
        curl -s https://ngrok-agent.s3.amazonaws.com/ngrok.asc | sudo tee /etc/apt/trusted.gpg.d/ngrok.asc > /dev/null
        echo "deb https://ngrok-agent.s3.amazonaws.com buster main" | sudo tee /etc/apt/sources.list.d/ngrok.list
        sudo apt update && sudo apt install ngrok

    - name: Allow port 8000 through UFW
      run: |
        sudo ufw allow 8000/tcp
        sudo ufw enable
        sudo ufw status

    - name: Start Ngrok
      run: |
        ngrok authtoken ${{ secrets.ngrok}}
        ngrok http 8000 &
        sleep 10  # Wait for ngrok to initialize
        NGROK_URL=$(curl --silent http://localhost:4040/api/tunnels | jq -r '.tunnels[0].public_url')
        echo "NGROK_URL=${NGROK_URL}" >> $GITHUB_ENV

    - name: Deploy FastAPI application
      run: |
        uvicorn scripts.main:app --host 0.0.0.0 --port 8000 &
        sleep 10  # Allow server to start
        echo "FastAPI app running at ${{ env.NGROK_URL }}"

    - name: Debug Running Services
      run: |
        echo "Running processes:"
        ps aux
        echo "Docker containers:"
        docker ps
        echo "Listening ports:"
        sudo netstat -tulpn