GOIOS_DEV_ID, GOIOS_TEAM_ID and GOIOS_APP_ID. The detect.go program in this directory will
attempt to auto-detect suitable values. Run it as

	go run detect.go

which will output something similar to

	export GOIOS_DEV_ID="iPhone Developer: ******@****.*** (XXXXXXXX)"
	export GOIOS_APP_ID=YYYYYYYY.some.bundle.id
	export GOIOS_TEAM_ID=ZZZZZZZZ

!!! 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.

In general, ASGI middlewares are classes that expect to receive an ASGI app as the first argument.

So, in the documentation for third-party ASGI middlewares they will probably tell you to do something like:

```Python
from unicorn import UnicornMiddleware

app = SomeASGIApp()

new_app = UnicornMiddleware(app, some_config="rainbow")
```

Most of these ideas would be more or less **independent**, and in most cases you should only need to study them if they apply directly to **your project**.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

!!! tip

The same as with SQLAlchemy, we are not doing something like:

```Python
user = await models.User.select().first()
```

...but instead we are using:

```Python
user = models.User.select().first()
```

So, again, we should declare the *path operation functions* and the dependency without `async def`, just with a normal `def`, as:

```Python hl_lines="2"
# Something goes here

    val handshake = makeRequest(client)

    assertThat(handshake.cipherSuite).isIn(*expectedModernTls12CipherSuites.toTypedArray())

    // Probably something like
    // TLS_AES_128_GCM_SHA256
    // TLS_AES_256_GCM_SHA384
    // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
    // TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
    // TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

# Controllers

Istio has a variety of [controllers](https://kubernetes.io/docs/concepts/architecture/controller/), which basically watch some inputs and do something.
This can be reading from Kubernetes and writing other objects back, writing to proxies over XDS, etc.

Unfortunately, writing controllers is very error prone, even for seemingly simple cases.
To work around this, Istio has a variety of abstractions meant to make writing controllers easier.

## Clients

Ein „**Callable**“ in Python ist etwas, das wie eine Funktion aufgerufen werden kann („to call“).

Wenn Sie also ein Objekt `something` haben (das möglicherweise _keine_ Funktion ist) und Sie es wie folgt aufrufen (ausführen) können:

```Python
something()
```

oder

```Python
something(some_argument, some_keyword_argument="foo")
```

dann ist das ein „Callable“ (ein „Aufrufbares“).

## Klassen als Abhängigkeiten

### Async Context Manager

If you check, the function is decorated with an `@asynccontextmanager`.

That converts the function into something called an "**async context manager**".

```Python hl_lines="1  13"
{!../../../docs_src/events/tutorial003.py!}
```

A **context manager** in Python is something that you can use in a `with` statement, for example, `open()` can be used as a context manager:

```Python
with open("file.txt") as file:

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