do not create new files for cloud storage transfer tests

storage/aws_test.go

@@ -10,14 +10,13 @@ import (
 
 func TestSnapshotS3Upload(test *testing.T) {
 	// test this fails at s3upload
-	fooFile, err := os.Create("./foo")
+	fooFile, err := os.Open("../.gitignore")
 	if err != nil {
-		test.Error("test short-circuited because file could not be created and opened")
+		test.Error("test short-circuited because file could not be opened")
 	}
 	defer fooFile.Close()
-	defer os.Remove("./foo")
 
-	if err := snapshotS3Upload(util.Container, fooFile, "prefix-foo"); err == nil || !strings.Contains(err.Error(), "get credentials: failed to refresh cached credentials") {
+	if err := snapshotS3Upload(util.Container, fooFile, ""); err == nil || !strings.Contains(err.Error(), "get credentials: failed to refresh cached credentials") {
 		test.Errorf("expected error (contains): get credentials: failed to refresh cached credentials, actual: %v", err)
 	}
 }

storage/gcp_test.go

@@ -9,14 +9,13 @@ import (
 
 func TestSnapshotCSUpload(test *testing.T) {
 	// test this fails at upload transfer
-	fooFile, err := os.Create("./foo")
+	fooFile, err := os.Open("../.gitignore")
 	if err != nil {
-		test.Error("test short-circuited because file could not be created and opened")
+		test.Error("test short-circuited because file could not be opened")
 	}
 	defer fooFile.Close()
-	defer os.Remove("./foo")
 
-	if err := snapshotCSUpload(util.Container, fooFile, "prefix-foo"); err == nil || err.Error() != "dialing: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information" {
+	if err := snapshotCSUpload(util.Container, fooFile, ""); err == nil || err.Error() != "dialing: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information" {
 		test.Errorf("expected error: dialing: google: could not find default credentials. See https://cloud.google.com/docs/authentication/external/set-up-adc for more information, actual: %v", err)
 	}
 }