Using OkHttp is easy. Its request/response API is designed with fluent builders and immutability. It
supports both synchronous blocking calls and async calls with callbacks.

A well behaved user agent
-------------------------

OkHttp follows modern HTTP specifications such as

* HTTP Semantics - [RFC 9110](https://datatracker.ietf.org/doc/html/rfc9110)

   * by the application:
   *
   * * It may be transformed by the user's interceptors. For example, an application interceptor
   *   may add headers like `User-Agent`.
   * * It may be the request generated in response to an HTTP redirect or authentication
   *   challenge. In this case the request URL may be different than the initial request URL.
   *

      Header("retry-after", ""),
      Header("server", ""),
      Header("set-cookie", ""),
      Header("strict-transport-security", ""),
      Header("transfer-encoding", ""),
      Header("user-agent", ""),
      Header("vary", ""),
      Header("via", ""),
      Header("www-authenticate", ""),
    )

  val NAME_TO_FIRST_INDEX = nameToFirstIndex()

- Kubernetes 1.12 includes a large number of metadata agent improvements, including expanding the metadata agent's access to all API groups and removing metadata agent config maps in favor of command line flags. It also includes improvements to the logging agent, such as multiple fixes and adjustments.

### Other notable changes

* Metadata Agent Improvements ([#66485](https://github.com/kubernetes/kubernetes/pull/66485), [@bmoyles0117](https://github.com/bmoyles0117))
    * Bump metadata agent version to 0.2-0.0.21-1.
    * Expand the metadata agent's access to all API groups.
    * Remove metadata agent config maps in favor of command line flags.

// Excerpts from @lsegal - https://github.com/aws/aws-sdk-js/issues/659#issuecomment-120477258
//
//	User-Agent:
//
//	    This is ignored from signing because signing this causes problems with generating pre-signed URLs
//	    (that are executed by other agents) or when customers pass requests through proxies, which may
//	    modify the user-agent.
//
//	Authorization:
//
//	    Is skipped for obvious reasons

    ```kotlin
      private val client = OkHttpClient()

      fun run() {
        val request = Request.Builder()
            .url("https://api.github.com/repos/square/okhttp/issues")
            .header("User-Agent", "OkHttp Headers.java")
            .addHeader("Accept", "application/json; q=0.5")
            .addHeader("Accept", "application/vnd.github.v3+json")
            .build()

* Add NoSchedule/NoExecute tolerations to ip-masq-agent, ensuring it to be scheduled in all nodes except master. ([#66260](https://github.com/kubernetes/kubernetes/pull/66260), [@tanshanshan](https://github.com/tanshanshan))
* Metadata Agent Improvements ([#66485](https://github.com/kubernetes/kubernetes/pull/66485), [@bmoyles0117](https://github.com/bmoyles0117))
    * Bump metadata agent version to 0.2-0.0.21-1.

   *
   * @since 28.1
   */
  public static final String UPGRADE_INSECURE_REQUESTS = "Upgrade-Insecure-Requests";

  /** The HTTP {@code User-Agent} header field name. */
  public static final String USER_AGENT = "User-Agent";

  // HTTP Response header fields

  /** The HTTP {@code Accept-Ranges} header field name. */
  public static final String ACCEPT_RANGES = "Accept-Ranges";

	loginPathPrefix = SlashSeparator + "login"
)

func guessIsBrowserReq(r *http.Request) bool {
	aType := getRequestAuthType(r)
	return strings.Contains(r.Header.Get("User-Agent"), "Mozilla") &&
		globalBrowserEnabled && aType == authTypeAnonymous
}

func setBrowserRedirectMiddleware(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {