adding ctx makes the cancel channel redundant

builder/amazon/common/step_get_password.go

@@ -46,14 +46,13 @@ func (s *StepGetPassword) Run(ctx context.Context, state multistep.StateBag) mul
 	// Get the password
 	var password string
 	var err error
-	cancel := make(chan struct{})
 	waitDone := make(chan bool, 1)
 	go func() {
 		ui.Say("Waiting for auto-generated password for instance...")
 		ui.Message(
 			"It is normal for this process to take up to 15 minutes,\n" +
 				"but it usually takes around 5. Please wait.")
-		password, err = s.waitForPassword(state, cancel, ctx)
+		password, err = s.waitForPassword(ctx, state)
 		waitDone <- true
 	}()
 
@@ -77,16 +76,12 @@ WaitLoop:
 			err := fmt.Errorf("Timeout waiting for password.")
 			state.Put("error", err)
 			ui.Error(err.Error())
-			close(cancel)
 			return multistep.ActionHalt
-		case <-time.After(1 * time.Second):
-			if _, ok := state.GetOk(multistep.StateCancelled); ok {
-				// The step sequence was cancelled, so cancel waiting for password
-				// and just start the halting process.
-				close(cancel)
-				log.Println("[WARN] Interrupt detected, quitting waiting for password.")
-				return multistep.ActionHalt
-			}
+		case <-ctx.Done():
+			// The step sequence was cancelled, so cancel waiting for password
+			// and just start the halting process.
+			log.Println("[WARN] Interrupt detected, quitting waiting for password.")
+			return multistep.ActionHalt
 		}
 	}
 
@@ -107,14 +102,14 @@ func (s *StepGetPassword) Cleanup(multistep.StateBag) {
 	commonhelper.RemoveSharedStateFile("winrm_password", s.BuildName)
 }
 
-func (s *StepGetPassword) waitForPassword(state multistep.StateBag, cancel <-chan struct{}, ctx context.Context) (string, error) {
+func (s *StepGetPassword) waitForPassword(ctx context.Context, state multistep.StateBag) (string, error) {
 	ec2conn := state.Get("ec2").(*ec2.EC2)
 	instance := state.Get("instance").(*ec2.Instance)
 	privateKey := s.Comm.SSHPrivateKey
 
 	for {
 		select {
-		case <-cancel:
+		case <-ctx.Done():
 			log.Println("[INFO] Retrieve password wait cancelled. Exiting loop.")
 			return "", errors.New("Retrieve password wait cancelled")
 		case <-time.After(5 * time.Second):