- kube-apiserver: a new `--requestheader-uid-headers` flag allows configuring request header authentication to obtain the authenticating user's UID from the specified headers. The suggested value for the new option is `X-Remote-Uid`. When specified, the `kube-system/extension-apiserver-authentication` configmap will include the value in its `.data[requestheader-uid-headers]` field. ([#115834](https://github.com/kubernetes/kubernetes/pull/115834), [@stlaz](...

- Changed: default "Accept-Encoding" header removed from HTTP probes. See https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#http-probes ([#96127](https://github.com/kubernetes/kubernetes/pull/96127), [@fonsecas72](https://github.com/fonsecas72)) [SIG Network and Node]

*   It is now possible to set multiple manifest URL headers with the kubelet's `--manifest-url-header` flag. Multiple headers for the same key will be added in the order provided. The ManifestURLHeader field in KubeletConfiguration object (kubeletconfig/v1alpha1) is now a map[string][]string, which facilitates writing JSON and YAML files....

pkg syscall (netbsd-arm64), type InterfaceAnnounceMessage struct
pkg syscall (netbsd-arm64), type InterfaceAnnounceMessage struct, Header IfAnnounceMsghdr
pkg syscall (netbsd-arm64), type InterfaceMessage struct
pkg syscall (netbsd-arm64), type InterfaceMessage struct, Data []uint8
pkg syscall (netbsd-arm64), type InterfaceMessage struct, Header IfMsghdr

- The `RemoteRequestHeaderUID` feature moves to beta and is now enabled by default. This makes the kube-apiserver propagate UIDs in the `X-Remote-Uid` header in requests to the aggregated API servers. The header is not honored by default for incoming requests, but that can be enabled by setting the `--requestheader-uid-headers` flag explicitly. ([#130560](https://github.com/kubernetes/kubernetes/pull/130560), [@stlaz](https://github.com/stlaz)) [SIG API Machinery, Auth and Testing]

pkg syscall (darwin-arm64), type InterfaceAddrMessage struct, Header IfaMsghdr
pkg syscall (darwin-arm64), type InterfaceMessage //deprecated
pkg syscall (darwin-arm64), type InterfaceMessage struct
pkg syscall (darwin-arm64), type InterfaceMessage struct, Data []uint8
pkg syscall (darwin-arm64), type InterfaceMessage struct, Header IfMsghdr
pkg syscall (darwin-arm64), type InterfaceMulticastAddrMessage //deprecated

- Kube-apiserver: sets an upper-bound on the lifetime of idle keep-alive connections and the time to read the headers of incoming requests. ([#103958](https://github.com/kubernetes/kubernetes/pull/103958), [@liggitt](https://github.com/liggitt))

* The `--insecure-allow-any-token` flag has been removed from the API server. Users of the flag should use impersonation headers instead for debugging. ([#49045](https://github.com/kubernetes/kubernetes/pull/49045), [@ericchiang](https://github.com/ericchiang))

request alternate representations of normal Kubernetes objects by passing an `Accept` header like `application/json;as=Table;g=meta.k8s.io;v=v1beta1` or `application/json;as=PartialObjectMetadata;g=meta.k8s.io;v1=v1beta1`.  Older servers will ignore this representation or return an error if it is not available.  Clients may request fallback to the normal object by adding a non-qualified mime-type to their `Accept` header like `application/json` - the server will then respond with either the alternate...

- Added a path `/header?key=` to `agnhost netexec` allowing one to view what the header value is of the incoming request.

  Ex:
  ```
  $ curl -H "X-Forwarded-For: something" 172.17.0.2:8080/header?key=X-Forwarded-For
  something
  ```