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/eventWatchHelper.go

@@ -0,0 +1,45 @@
+package kubernetes
+
+import (
+	"context"
+	"regexp"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/watch"
+)
+
+type EventWatchHelper struct {
+	kubernetesProvider *Provider
+	NameRegexFilter *regexp.Regexp
+}
+
+func NewEventWatchHelper(kubernetesProvider *Provider, NameRegexFilter *regexp.Regexp) *EventWatchHelper {
+	return &EventWatchHelper{
+		kubernetesProvider: kubernetesProvider,
+		NameRegexFilter: NameRegexFilter,
+	}
+}
+
+// Implements the EventFilterer Interface
+func (wh *EventWatchHelper) Filter(wEvent *WatchEvent) (bool, error) {
+	event, err := wEvent.ToEvent()
+	if err != nil {
+		return false, nil
+	}
+
+	if !wh.NameRegexFilter.MatchString(event.Name) {
+		return false, nil
+	}
+
+	return true, nil
+}
+
+// Implements the WatchCreator Interface
+func (wh *EventWatchHelper) NewWatcher(ctx context.Context, namespace string) (watch.Interface, error) {
+	watcher, err := wh.kubernetesProvider.clientSet.EventsV1().Events(namespace).Watch(ctx, metav1.ListOptions{Watch: true})
+	if err != nil {
+		return nil, err
+	}
+
+	return watcher, nil
+}

shared/kubernetes/podWatchHelper.go

@@ -21,13 +21,13 @@ func NewPodWatchHelper(kubernetesProvider *Provider, NameRegexFilter *regexp.Reg
 }
 
 // Implements the EventFilterer Interface
-func (pwh *PodWatchHelper) Filter(wEvent *WatchEvent) (bool, error) {
+func (wh *PodWatchHelper) Filter(wEvent *WatchEvent) (bool, error) {
 	pod, err := wEvent.ToPod()
 	if err != nil {
 		return false, nil
 	}
 
-	if !pwh.NameRegexFilter.MatchString(pod.Name) {
+	if !wh.NameRegexFilter.MatchString(pod.Name) {
 		return false, nil
 	}
 
@@ -35,8 +35,8 @@ func (pwh *PodWatchHelper) Filter(wEvent *WatchEvent) (bool, error) {
 }
 
 // Implements the WatchCreator Interface
-func (pwh *PodWatchHelper) NewWatcher(ctx context.Context, namespace string) (watch.Interface, error) {
-	watcher, err := pwh.kubernetesProvider.clientSet.CoreV1().Pods(namespace).Watch(ctx, metav1.ListOptions{Watch: true})
+func (wh *PodWatchHelper) NewWatcher(ctx context.Context, namespace string) (watch.Interface, error) {
+	watcher, err := wh.kubernetesProvider.clientSet.CoreV1().Pods(namespace).Watch(ctx, metav1.ListOptions{Watch: true})
 	if err != nil {
 		return nil, err
 	}

shared/kubernetes/provider.go

@@ -485,6 +485,11 @@ func (provider *Provider) CreateDaemonsetRBAC(ctx context.Context, namespace str
 				Resources: []string{"daemonsets"},
 				Verbs:     []string{"patch", "get", "list", "create", "delete"},
 			},
+			{
+				APIGroups: []string{"events.k8s.io"},
+				Resources: []string{"events"},
+				Verbs:     []string{"list", "watch"},
+			},
 		},
 	}
 	roleBinding := &rbac.RoleBinding{

shared/kubernetes/watch.go

@@ -9,7 +9,6 @@ import (
 	"sync"
 	"time"
 
-	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/watch"
 )
 
@@ -39,7 +38,7 @@ func FilteredWatch(ctx context.Context, watcherCreator WatchCreator, targetNames
 			for {
 				watcher, err := watcherCreator.NewWatcher(ctx, targetNamespace)
 				if err != nil {
-					errorChan <- fmt.Errorf("error in k8 watch: %v", err)
+					errorChan <- fmt.Errorf("error in k8s watch: %v", err)
 					break
 				}
 
@@ -54,7 +53,7 @@ func FilteredWatch(ctx context.Context, watcherCreator WatchCreator, targetNames
 				}
 
 				if err != nil {
-					errorChan <- fmt.Errorf("error in k8 watch: %v", err)
+					errorChan <- fmt.Errorf("error in k8s watch: %v", err)
 					break
 				} else {
 					if !watchRestartDebouncer.IsOn() {
@@ -95,7 +94,7 @@ func startWatchLoop(ctx context.Context, watcher watch.Interface, filterer Event
 			wEvent := WatchEvent(e)
 
 			if wEvent.Type == watch.Error {
-				return apierrors.FromObject(wEvent.Object)
+				return wEvent.ToError()
 			}
 
 			if pass, err := filterer.Filter(&wEvent); err != nil {

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)
+}