Bumping k8s dependencies to 1.13

vendor/github.com/modern-go/concurrent/README.md

@@ -8,4 +8,42 @@
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://raw.githubusercontent.com/modern-go/concurrent/master/LICENSE)
 
 * concurrent.Map: backport sync.Map for go below 1.9
-* concurrent.Executor: goroutine with explicit ownership and cancellable
+* concurrent.Executor: goroutine with explicit ownership and cancellable
+
+# concurrent.Map
+
+because sync.Map is only available in go 1.9, we can use concurrent.Map to make code portable
+
+```go
+m := concurrent.NewMap()
+m.Store("hello", "world")
+elem, found := m.Load("hello")
+// elem will be "world"
+// found will be true
+```
+
+# concurrent.Executor
+
+```go
+executor := concurrent.NewUnboundedExecutor()
+executor.Go(func(ctx context.Context) {
+    everyMillisecond := time.NewTicker(time.Millisecond)
+    for {
+        select {
+        case <-ctx.Done():
+            fmt.Println("goroutine exited")
+            return
+        case <-everyMillisecond.C:
+            // do something
+        }
+    }
+})
+time.Sleep(time.Second)
+executor.StopAndWaitForever()
+fmt.Println("executor stopped")
+```
+
+attach goroutine to executor instance, so that we can
+
+* cancel it by stop the executor with Stop/StopAndWait/StopAndWaitForever
+* handle panic by callback: the default behavior will no longer crash your application

vendor/github.com/modern-go/concurrent/unbounded_executor.go

@@ -16,9 +16,6 @@ var HandlePanic = func(recovered interface{}, funcName string) {
 	ErrorLogger.Println(string(debug.Stack()))
 }
 
-// StopSignal will not be recovered, will propagate to upper level goroutine
-const StopSignal = "STOP!"
-
 // UnboundedExecutor is a executor without limits on counts of alive goroutines
 // it tracks the goroutine started by it, and can cancel them when shutdown
 type UnboundedExecutor struct {
@@ -62,7 +59,9 @@ func (executor *UnboundedExecutor) Go(handler func(ctx context.Context)) {
 	go func() {
 		defer func() {
 			recovered := recover()
-			if recovered != nil && recovered != StopSignal {
+			// if you want to quit a goroutine without trigger HandlePanic
+			// use runtime.Goexit() to quit
+			if recovered != nil {
 				if executor.HandlePanic == nil {
 					HandlePanic(recovered, funcName)
 				} else {
@@ -70,8 +69,8 @@ func (executor *UnboundedExecutor) Go(handler func(ctx context.Context)) {
 				}
 			}
 			executor.activeGoroutinesMutex.Lock()
-			defer executor.activeGoroutinesMutex.Unlock()
 			executor.activeGoroutines[startFrom] -= 1
+			executor.activeGoroutinesMutex.Unlock()
 		}()
 		handler(executor.ctx)
 	}()
@@ -93,24 +92,24 @@ func (executor *UnboundedExecutor) StopAndWaitForever() {
 func (executor *UnboundedExecutor) StopAndWait(ctx context.Context) {
 	executor.cancel()
 	for {
-		fiveSeconds := time.NewTimer(time.Millisecond * 100)
+		oneHundredMilliseconds := time.NewTimer(time.Millisecond * 100)
 		select {
-		case <-fiveSeconds.C:
+		case <-oneHundredMilliseconds.C:
+			if executor.checkNoActiveGoroutines() {
+				return
+			}
 		case <-ctx.Done():
 			return
 		}
-		if executor.checkGoroutines() {
-			return
-		}
 	}
 }
 
-func (executor *UnboundedExecutor) checkGoroutines() bool {
+func (executor *UnboundedExecutor) checkNoActiveGoroutines() bool {
 	executor.activeGoroutinesMutex.Lock()
 	defer executor.activeGoroutinesMutex.Unlock()
 	for startFrom, count := range executor.activeGoroutines {
 		if count > 0 {
-			InfoLogger.Println("event!unbounded_executor.still waiting goroutines to quit",
+			InfoLogger.Println("UnboundedExecutor is still waiting goroutines to quit",
 				"startFrom", startFrom,
 				"count", count)
 			return false

vendor/github.com/modern-go/concurrent/unbounded_executor_test.go

@@ -32,10 +32,10 @@ func ExampleUnboundedExecutor_StopAndWaitForever() {
 	})
 	time.Sleep(time.Second)
 	executor.StopAndWaitForever()
-	fmt.Println("exectuor stopped")
+	fmt.Println("executor stopped")
 	// output:
 	// goroutine exited
-	// exectuor stopped
+	// executor stopped
 }
 
 func ExampleUnboundedExecutor_Go_panic() {