dont open ssh tempfile exclusively (#137)

* dont open ssh tempfile exclusively

* disable bad unit test

* add explanatory comment

google_guest_agent/accounts_test.go

@@ -95,7 +95,10 @@ func TestAccountsDisabled(t *testing.T) {
 	}
 }
 
-func TestNewPwd(t *testing.T) {
+// rename this with leading disabled because this is a resource
+// intensive test. this test takes approx. 141 seconds to complete, next
+// longest test is 0.43 seconds.
+func disabledTestNewPwd(t *testing.T) {
 	minPasswordLength := 15
 	maxPasswordLength := 255
 	var tests = []struct {

google_guest_agent/non_windows_accounts.go

@@ -486,7 +486,7 @@ func updateAuthorizedKeysFile(user string, keys []string) error {
 		userKeys = append(userKeys, key)
 	}
 
-	newfile, err := os.OpenFile(tempPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0600)
+	newfile, err := os.OpenFile(tempPath, os.O_WRONLY|os.O_CREATE, 0600)
 	if err != nil {
 		return err
 	}