)

const (
	// Location to read istioctl defaults from
	defaultIstioctlConfig = "$HOME/.istioctl/config.yaml"
)

var (
	// IstioConfig is the name of the istioctl config file (if any)
	IstioConfig = env.Register("ISTIOCONFIG", defaultIstioctlConfig,
		"Default values for istioctl flags").Get()

	LoggingOptions = defaultLogOptions()

	LogFormat  = "log"
	JSONFormat = "json"
	YAMLFormat = "yaml"
)

var (
	MsgOutputFormatKeys = []string{LogFormat, JSONFormat, YAMLFormat}
	MsgOutputFormats    = make(map[string]bool)
	termEnvVar          = env.Register("TERM", "", "Specifies terminal type.  Use 'dumb' to suppress color output")
)

func init() {
	for _, key := range MsgOutputFormatKeys {
		MsgOutputFormats[key] = true
	}
}

// RawExtension is used to hold extensions in external versions.
//
// To use this, make a field which has RawExtension as its type in your external, versioned
// struct, and Object in your internal struct. You also need to register your
// various plugin types.
//
// // Internal package:
//
// 	type MyAPIObject struct {
// 		runtime.TypeMeta `json:",inline"`
// 		MyPlugin runtime.Object `json:"myPlugin"`
// 	}
//

	"istioNamespace":      env.Register("ISTIOCTL_ISTIONAMESPACE", constants.IstioSystemNamespace, "The istioctl --istioNamespace override"),
	"xds-address":         env.Register("ISTIOCTL_XDS_ADDRESS", "", "The istioctl --xds-address override"),
	"xds-port":            env.Register("ISTIOCTL_XDS_PORT", 15012, "The istioctl --xds-port override"),
	"authority":           env.Register("ISTIOCTL_AUTHORITY", "", "The istioctl --authority override"),

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.
Often, these handlers are adding something to the queue like `client.AddEventHandler(controllers.ObjectHandler(queue.AddObject))`.