Add test for image in node status

pkg/util/rand/rand.go

@@ -32,7 +32,7 @@ var rng = struct {
 	rand: rand.New(rand.NewSource(time.Now().UTC().UnixNano())),
 }
 
-// Intn generates an integer in range 0->max.
+// Intn generates an integer in range [0,max).
 // By design this should panic if input is invalid, <= 0.
 func Intn(max int) int {
 	rng.Lock()
@@ -40,6 +40,22 @@ func Intn(max int) int {
 	return rng.rand.Intn(max)
 }
 
+// IntnRange generates an integer in range [min,max).
+// By design this should panic if input is invalid, <= 0.
+func IntnRange(min, max int) int {
+	rng.Lock()
+	defer rng.Unlock()
+	return rng.rand.Intn(max-min) + min
+}
+
+// IntnRange generates an int64 integer in range [min,max).
+// By design this should panic if input is invalid, <= 0.
+func Int63nRange(min, max int64) int64 {
+	rng.Lock()
+	defer rng.Unlock()
+	return rng.rand.Int63n(max-min) + min
+}
+
 // Seed seeds the rng with the provided seed.
 func Seed(seed int64) {
 	rng.Lock()