[Ingest Manager] Agent longpoll (elastic#19244)

* init

* simple things made simple

* Update fleet_gateway.go

x-pack/elastic-agent/pkg/agent/application/fleet_gateway.go

@@ -19,11 +19,11 @@ import (
 
 // Default Configuration for the Fleet Gateway.
 var defaultGatewaySettings = &fleetGatewaySettings{
-	Duration: 30 * time.Second,
-	Jitter:   5 * time.Second,
-	Backoff: backoffSettings{
-		Init: 1 * time.Second,
-		Max:  10 * time.Second,
+	Duration: 1 * time.Second,        // time between successful calls
+	Jitter:   500 * time.Millisecond, // used as a jitter for duration
+	Backoff: backoffSettings{ // time after a failed call
+		Init: 5 * time.Second,
+		Max:  60 * time.Second,
 	},
 }
 

x-pack/elastic-agent/pkg/kibana/client.go

@@ -104,7 +104,7 @@ func NewWithRawConfig(log *logger.Logger, config *config.Config, wrapper wrapper
 
 	cfg := &Config{}
 	if err := config.Unpack(cfg); err != nil {
-		return nil, errors.Wrap(err, "invidate configuration")
+		return nil, errors.Wrap(err, "invalidate configuration")
 	}
 
 	return NewWithConfig(l, cfg, wrapper)