**FastAPI**'s `UploadFile` inherits directly from **Starlette**'s `UploadFile`, but adds some necessary parts to make it compatible with **Pydantic** and the other parts of FastAPI.

## What is "Form Data"

The way HTML forms (`<form></form>`) sends the data to the server normally uses a "special" encoding for that data, it's different from JSON.

**FastAPI** will make sure to read that data from the right place instead of JSON.

1. Config ingestion (inputs to the system)
1. Config translation
1. Config serving (XDS)

### Config Ingestion

Istio reads from over 20 different resources types, and aggregates them together to build the proxy configuration. These resources can be sourced from Kubernetes (via watches), files, or over xDS; Kubernetes is by far the most common usage, though.

Primarily for historical reasons, ingestion is split into a few components.

      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,

      MockResponse(body = "unexpected call to IPv4"),
    )
    serverIpv6.enqueue(
      MockResponse(body = "hello from IPv6"),
    )

    val call = client.newCall(Request(url))
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("hello from IPv6")

    // In the process we made one successful connection attempt.

## Example upgrade

Now modify the file `main.py` to receive a body from a `PUT` request.

Declare the body using standard Python types, thanks to Pydantic.

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float

!!! note "Technical Details"
    You could also use `from starlette.responses import HTMLResponse`.

    **FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette.

### `Response`

The main `Response` class, all the other responses inherit from it.

You can return it directly.

      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,

      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,

- ISTIO_META_DNS_CAPTURE env variable on the proxy - enables dns redirect
- INVALID_DROP env var on proxy - changes behavior from reset to drop in iptables
- auto excluded inbound ports: 15020, 15021, 15090

The code automatically detects the proxyUID and proxyGID from RunAsUser/RunAsGroup and exclude them from interception, defaulting to 1337

### Overview

- [istio-cni Helm chart](../manifests/charts/istio-cni/templates)

message RollingUpdateStatefulSetStrategy {
  // Partition indicates the ordinal at which the StatefulSet should be partitioned
  // for updates. During a rolling update, all pods from ordinal Replicas-1 to
  // Partition are updated. All pods from ordinal Partition-1 to 0 remain untouched.
  // This is helpful in being able to do a canary based deployment. The default value is 0.
  // +optional
  optional int32 partition = 1;