Handle possible error in WaitForSpecific func

In some situations we need to be aware of errors
to basically return it rather than polling again
and angain until the timeout.

Signed-off-by: Guillaume Giamarchi <guillaume.giamarchi@gmail.com>

utils/utils.go

@@ -94,9 +94,13 @@ func CopyFile(src, dst string) error {
 	return nil
 }
 
-func WaitForSpecific(f func() bool, maxAttempts int, waitInterval time.Duration) error {
+func WaitForSpecificOrError(f func() (bool, error), maxAttempts int, waitInterval time.Duration) error {
 	for i := 0; i < maxAttempts; i++ {
-		if f() {
+		stop, err := f()
+		if err != nil {
+			return err
+		}
+		if stop {
 			return nil
 		}
 		time.Sleep(waitInterval)
@@ -104,6 +108,12 @@ func WaitForSpecific(f func() bool, maxAttempts int, waitInterval time.Duration)
 	return fmt.Errorf("Maximum number of retries (%d) exceeded", maxAttempts)
 }
 
+func WaitForSpecific(f func() bool, maxAttempts int, waitInterval time.Duration) error {
+	return WaitForSpecificOrError(func() (bool, error) {
+		return f(), nil
+	}, maxAttempts, waitInterval)
+}
+
 func WaitFor(f func() bool) error {
 	return WaitForSpecific(f, 60, 3*time.Second)
 }