& `Response` 💪 ⚙️ 🛎 ⚒ 🎚 & 🍪, **FastAPI** 🚚 ⚫️ `fastapi.Response`.

## 🛃 🎚

✔️ 🤯 👈 🛃 © 🎚 💪 🚮 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">⚙️ '✖-' 🔡</a>.

- https://github.com/istio/istio/issues/17635
releaseNotes:
  - |
    **Added** a new configuration to `ProxyHeaders`, `MetadataExchangeHeaders`. The `IN_MESH` mode ensures `x-envoy-peer-metadata` and `x-envoy-peer-metadata-id`

## Duplicate headers

It is possible to receive duplicate headers. That means, the same header with multiple values.

You can define those cases using a list in the type declaration.

You will receive all the values from the duplicate header as a Python `list`.

For example, to declare a header of `X-Token` that can appear more than once, you can write:

// [CanonicalHeaderKey].
func (h Header) Del(key string) {
	textproto.MIMEHeader(h).Del(key)
}

// Write writes a header in wire format.
func (h Header) Write(w io.Writer) error {
	return h.write(w, nil)
}

func (h Header) write(w io.Writer, trace *httptrace.ClientTrace) error {
	return h.writeSubset(w, nil, trace)
}

// Clone returns a copy of h or nil if h is nil.
func (h Header) Clone() Header {
	if h == nil {

docs:
 - '[reference] https://istio.io/latest/docs/reference/commands/pilot-discovery/'

releaseNotes:
- |
  **Added** an `ENABLE_LEADER_ELECTION=false` feature flag for pilot-discovery

Laura Kassovic <******@****.***> 1701107622 -0800

apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: duplicate-header-match
spec:
  rules:
  - matches:
    - headers:
      - name: foo
        value: bar
      - name: foo

    val headers1 =
      Headers.Builder()
        .add("Connection", "close")
        .add("Transfer-Encoding", "chunked")
        .build()
    val headers2 =
      Headers.Builder()
        .add("Connection", "keep-alive")
        .add("Transfer-Encoding", "chunked")
        .build()
    assertThat(headers2).isNotEqualTo(headers1)
    assertThat(headers2.hashCode()).isNotEqualTo(headers1.hashCode().toLong())
  }

  name: appendh-route
  namespace: testns
spec:
  hosts:
    - appendh.test.istio.io
  http:
    - route:
      - destination:
          host: appendh.test.istio.io
      headers:
        request:
          add:

// Package iotest implements Readers and Writers useful mainly for testing.
package iotest

import (
	"bytes"
	"errors"
	"fmt"
	"io"
)

// OneByteReader returns a Reader that implements
// each non-empty Read by reading one byte from r.
func OneByteReader(r io.Reader) io.Reader { return &oneByteReader{r} }

type oneByteReader struct {
	r io.Reader
}