Warn pods not starting (#493)

Print warning event related to mizu k8s resources.
In non-daemon print to CLI. In Daemon print to API-Server logs.

shared/kubernetes/watchEvent.go

@@ -2,17 +2,43 @@ package kubernetes
 
 import (
 	"fmt"
+	"reflect"
+
 	corev1 "k8s.io/api/core/v1"
+	eventsv1 "k8s.io/api/events/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/watch"
 )
 
+type InvalidObjectType struct {
+	RequestedType reflect.Type
+}
+
+// Implements the error interface
+func (iot *InvalidObjectType) Error() string {
+	return fmt.Sprintf("Cannot convert event to type %s", iot.RequestedType)
+}
+
 type WatchEvent watch.Event
 
 func (we *WatchEvent) ToPod() (*corev1.Pod, error) {
 	pod, ok := we.Object.(*corev1.Pod)
 	if !ok {
-		return nil, fmt.Errorf("Invalid object type on pod event stream")
+		return nil, &InvalidObjectType{RequestedType: reflect.TypeOf(pod)}
 	}
 
 	return pod, nil
 }
+
+func (we *WatchEvent) ToEvent() (*eventsv1.Event, error) {
+	event, ok := we.Object.(*eventsv1.Event)
+	if !ok {
+		return nil, &InvalidObjectType{RequestedType: reflect.TypeOf(event)}
+	}
+
+	return event, nil
+}
+
+func (we *WatchEvent) ToError() error {
+	return apierrors.FromObject(we.Object)
+}