Fly.io Hosting for Flet Applications

Fly.io offers robust WebSocket support and global data center deployment for Flet web applications. It provides a generous free tier for hosting up to 3 applications.

Prerequisites

**Install flyctl**: Follow instructions at [fly.io/docs/getting-started/installing-flyctl/](https://fly.io/docs/getting-started/installing-flyctl/).

**Authenticate flyctl**: Run fly auth login.

Project Files

Place the following files in your Python application's root directory:

**requirements.txt**: Lists application dependencies.

    flet
    

**fly.toml**: Describes the Fly application configuration.

    app = ""
    kill_signal = "SIGINT"
    kill_timeout = 5
    processes = []
    [env]
      FLET_SESSION_TIMEOUT = "60"
    [http_service]
      internal_port = 8000
      force_https = true
      auto_stop_machines = true
      auto_start_machines = true
      min_machines_running = 0
      [http_service.concurrency]
        type = "connections"
        soft_limit = 200
        hard_limit = 250
    

* Replace with your desired application name. This name also forms the application URL (e.g., https://.fly.dev). * FLET_SESSION_TIMEOUT: Sets user session lifetime in seconds (default: 60). * The Flet web app defaults to port 8000. This can be changed via the FLET_SERVER_PORT environment variable. * Refer to [Flet Web App Environment Variables](https://docs.flet.dev/publish/web/dynamic-website/#environment-variables) for a complete list.

**Dockerfile**: Defines the application container build process.

    FROM python:3-alpine
    WORKDIR /app
    COPY requirements.txt ./
    RUN pip install --no-cache-dir -r requirements.txt
    COPY . .
    EXPOSE 8000
    CMD ["python", "main.py"]
    

* main.py is your main Python application file. * Fly.io uses Docker containers and provides a free remote Docker builder.

Deployment Steps

1. **Create Fly App**: Navigate to your app's directory in the terminal and run:

    fly apps create --name 
    

2. **Deploy App**: Run the deploy command:

    fly deploy
    

3. **Open App**: Access your deployed application in the browser:

    fly apps open
    

Regions

Fly.io allows deploying apps to data centers close to users. See [Fly.io Regions](https://fly.io/docs/reference/regions/).

Pricing

Fly.io offers attractive pricing with a free tier. See [Fly.io Pricing](https://fly.io/docs/about/pricing/#free-allowances).