!!! info "`@decorator` Info"
    That `@something` syntax in Python is called a "decorator".

    You put it on top of a function. Like a pretty decorative hat (I guess that's where the term came from).

    A "decorator" takes the function below and does something with it.

    "servers": [
        {
            "url": "/api/v1"
        }
    ],
    "paths": {
            // More stuff here
    }
}
```

In this example, the "Proxy" could be something like **Traefik**. And the server would be something like FastAPI CLI with **Uvicorn**, running your FastAPI application.

### Providing the `root_path`

To achieve this, you can use the command line option `--root-path` like:

<div class="termy">

We also saw that HTTPS is normally provided by a component **external** to your application server, a **TLS Termination Proxy**.

And there has to be something in charge of **renewing the HTTPS certificates**, it could be the same component or it could be something different.

### Example Tools for HTTPS

Some of the tools you could use as a TLS Termination Proxy are:

* Traefik

        That including `uvloop`, the high-performance drop-in replacement for `asyncio`, that provides the big concurrency performance boost.

        When you install FastAPI with something like `pip install fastapi` you already get `uvicorn[standard]` as well.

=== "Hypercorn"

!!! tip
    The actual callback is just an HTTP request.

    When implementing the callback yourself, you could use something like <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a> or <a href="https://requests.readthedocs.io/" class="external-link" target="_blank">Requests</a>.

## Write the callback documentation code

    But keep in mind that, as everything is handled in memory, in a single list, it will only work while the process is running, and will only work with a single process.

    If you need something easy to integrate with FastAPI but that is more robust, supported by Redis, PostgreSQL or others, check <a href="https://github.com/encode/broadcaster" class="external-link" target="_blank">encode/broadcaster</a>.

## More info

But it's not possible to have a running container without **at least one running process**. If the main process stops, the container stops.

## Build a Docker Image for FastAPI

Okay, let's build something now! 🚀

I'll show you how to build a **Docker image** for FastAPI **from scratch**, based on the **official Python** image.

This is what you would want to do in **most cases**, for example:

```Python
async def do_something():
    try:
        yield something
    finally:
        some_cleanup()
```

...that way the `finally` block is run regardless of any exception that might happen.

### Features

    ```Python hl_lines="2  5-8  11"
    {!> ../../../docs_src/settings/tutorial001_pv1.py!}
    ```

!!! tip
    If you want something quick to copy and paste, don't use this example, use the last one below.