Fix termination tests randomly timing out

Unit tests are run in random order. Termination tests also verify the
polling logic of the respective code, by atomically incrementing a
counter in each call of the HTTP handler. The issues fixed with these
changes are:

1. counter var not being reset after each termination test using polling
2. using the polling iterations loop in termination tests that were not
   using the HTTP handler that increments the counter
3. polling iterations loop not using sleep between iterations, which
   spikes CPU usage

The first two issues led to the termination tests sometimes passing,
depending on which termination test run first. If it was a test that
incremented the polling counter, then all other test would be successful
as well. If it was a test that didn't increment the polling counter,
then the termination tests would be stuck in an endless loop, until the
unit tests reached a timeout.

Signed-off-by: Michail Resvanis <mresvani@redhat.com>

pkg/termination/termination_test.go

@@ -124,6 +124,8 @@ var _ = Describe("Handler Suite", func() {
 		var counter int32
 
 		BeforeEach(func() {
+			counter = 0
+
 			// Ensure the polling logic is excercised in tests
 			httpHandler = newMockHTTPHandler(func(rw http.ResponseWriter, req *http.Request) {
 				if atomic.LoadInt32(&counter) == 4 {
@@ -135,15 +137,15 @@ var _ = Describe("Handler Suite", func() {
 			})
 		})
 
-		JustBeforeEach(func() {
-			// Ensure the polling logic is excercised in tests
-			for atomic.LoadInt32(&counter) < 4 {
-				continue
-			}
-		})
-
 		Context("and the handler is stopped", func() {
 			JustBeforeEach(func() {
+				// Ensure the polling logic is tested as well
+				for atomic.LoadInt32(&counter) < 4 {
+					// use 50ms since polling is set to 100ms
+					time.Sleep(50 * time.Millisecond)
+					continue
+				}
+
 				close(stop)
 			})
 
@@ -157,6 +159,15 @@ var _ = Describe("Handler Suite", func() {
 		})
 
 		Context("and the instance termination notice is fulfilled", func() {
+			JustBeforeEach(func() {
+				// Ensure the polling logic is tested as well
+				for atomic.LoadInt32(&counter) < 4 {
+					// use 50ms since polling is set to 100ms
+					time.Sleep(50 * time.Millisecond)
+					continue
+				}
+			})
+
 			It("should mark the node for deletion", func() {
 				Eventually(nodeMarkedForDeletion(testNode.Name)).Should(BeTrue())
 			})