## About third party integrations

In this example we are using the OAuth2 "password" flow.

This is appropriate when we are logging in to our own application, probably with our own frontend.

Because we can trust it to receive the `username` and `password`, as we control it.

  // "Indexed" in a text format. The indexes are represented as decimal integers
  // separated by commas. The numbers are listed in increasing order. Three or
  // more consecutive numbers are compressed and represented by the first and
  // last element of the series, separated by a hyphen.
  // For example, if the completed indexes are 1, 3, 4, 5 and 7, they are
  // represented as "1,3-5,7".
  // +optional

With a few exceptions, Istio controllers typically are split in two phases: construction and running.

Construction should create informers (via `kclient.New`), setup a queue (via `controllers.NewQueue`), and register event handlers on the informers.

  //                     required by the PodDisruptionBudget. No disruptions are
  //                     allowed and the status of the condition will be False.
  // - SufficientPods: There are more pods than required by the PodDisruptionBudget.
  //                   The condition will be True, and the number of allowed
  //                   disruptions are provided by the disruptionsAllowed property.
  //

Note that when adding a lazy property to an existing class, you need to check if instances of the class are instantiated via ObjectFactory. Most classes are instantiated this way, but it's possible that a class without any lazy properties was never updated to use it. A tell-tale sign that an object is not instantiated via the ObjectFactory are direct calls to the constructor with new.

### Existing properties in existing classes

# Usage

## Single Payload Requests

Single payload requests are requests and responses that are sent in a single message.
In essence, they are `[]byte` -> `[]byte, error` functions.

It is not possible to return *both* an error and a response.

Handlers are registered on the manager using `(*Manager).RegisterSingleHandler(id HandlerID, h SingleHandlerFn, subroute ...string)`.

   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *
   * <p>This method is not type-safe, as it may be called on a map with keys that are not mutually
   * comparable.
   *
   * @throws ClassCastException if the keys in {@code map} are not mutually comparable
   * @throws NullPointerException if any key or value in {@code map} is null

	Metrics bool   `msg:"m"`
	NoOp    bool   `msg:"np"`
}

// DiskInfo is an extended type which returns current
// disk usage per path.
// The above means that any added/deleted fields are incompatible.
//
// The above means that any added/deleted fields are incompatible.
//
//msgp:tuple DiskInfo
type DiskInfo struct {
	Total      uint64
	Free       uint64
	Used       uint64
	UsedInodes uint64
	FreeInodes uint64

Beautiful illustrations by <a href="https://www.instagram.com/ketrinadrawsalot" class="external-link" target="_blank">Ketrina Thompson</a>. 🎨

///

---

Imagine you are the computer / program 🤖 in that story.

While you are at the line, you are just idle 😴, waiting for your turn, not doing anything very "productive". But the line is fast because the cashier is only taking the orders (not preparing them), so that's fine.

So, all these are different origins:

* `http://localhost`
* `https://localhost`
* `http://localhost:8080`

Even if they are all in `localhost`, they use different protocols or ports, so, they are different "origins".

## Steps