!!! 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.

### 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:

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

	netns io.Closer
	fd    uintptr
	inode uint64
}

func (n *NetnsWithFd) Close() error {
	if n.netns == nil {
		return nil
	}

	ret := n.netns.Close()
	// set fd to invalid value, so if something uses it by mistake it will err
	uintZero := uintptr(0)
	n.fd = ^uintZero
	return ret
}

func (n *NetnsWithFd) Fd() uintptr {
	return n.fd
}

func (n *NetnsWithFd) Inode() uint64 {
	return n.inode

    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

    sourceCompatibility(JavaVersion.VERSION_11)
  }

  kotlinOptions {
    jvmTarget = JavaVersion.VERSION_11.toString()
  }

  // issue merging due to conflict with httpclient and something else
  packagingOptions.resources.excludes += setOf(
    "META-INF/DEPENDENCIES"
  )
}


dependencies {
  val okhttpLegacyVersion = "3.12.12"

  implementation(libs.kotlin.reflect)

  workflow_dispatch:

permissions: {}

jobs:
  feedback:
    permissions:
      issues: write
      pull-requests: write
    runs-on: ubuntu-latest
    steps:
      # Feedback loop: ask for something on PR/Issue and close if not provided or return to the queue on update.
      # https://github.com/gradle/issue-management-action/blob/main/src/feedback.ts
      - uses: gradle/issue-management-action@v1
        with:

name: Bug Report
description: Something is not working as expected
labels: ["type=defect"]
body:
  - type: markdown
    attributes:
      value: >
        Thank you for filing a bug report. Please help us identify and resolve the bug by filling
        out the following fields.

  - type: textarea
    attributes:
      label: Description
      description: Please describe the issue you encountered.
    validations:
      required: true

# 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

    "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">