Fly.io
Fly.io has robust WebSocket support and can deploy your app to a data center that is close to your users. They have very attractive pricing with a generous free tier which allows you to host up to 3 applications for free.
To get started with Fly install flyctl and then authenticate:
fly auth login
To deploy the app with flyctl you have to add the following 3 files into the folder with your Python app.
Create requirements.txt with a list of application dependencies. At minimum it should contain flet module:
flet
Create fly.toml describing Fly application:
app = "<your-app-name>"
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 <your-app-name> with desired application name which will be also used in application URL, such as https://<your-app-name>.fly.dev.
By default, Flet web app will be running on port 8000, but you can change that by setting up FLET_SERVER_PORT environment variable.
FLET_SESSION_TIMEOUT is a user session lifetime, in seconds.
Complete list of environment variables supported by a web app.
Create Dockerfile containing the commands to build your application container:
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 a file with your Python program.
Fly.io deploys every app as a Docker container, but a great thing about Fly is that it provides a free remote Docker builder, so you don't need Docker installed on your machine.
Next, switch command line to a folder with your app and run the following command to create and initialize a new Fly app:
fly apps create --name <your-app-name>
Deploy the app by running:
fly deploy
That's it! Open your app in the browser by running:
fly apps open