user_data: fix error when user-data is not utf-8 decodable

when user-data was not decodable, cloud-init would raise exception.
This also changes the signature of user_data.convert_string.
The 'headers' argument was never used, and woudl have been broken
if it was, as it was expected to be a dictionary but then was
passed in with *headers.

LP: #1532072

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/unittests/test_data.py b/tests/unittests/test_data.py
index 1923e2af..13db8a4c 100644
--- a/tests/unittests/test_data.py
+++ b/tests/unittests/test_data.py
@@ -557,3 +557,20 @@ class TestUDProcess(helpers.ResourceUsingTestCase):
         ud_proc = ud.UserDataProcessor(self.getCloudPaths())
         message = ud_proc.process(msg)
         self.assertTrue(count_messages(message) == 1)
+
+
+class TestConvertString(helpers.TestCase):
+    def test_handles_binary_non_utf8_decodable(self):
+        blob = b'\x32\x99'
+        msg = ud.convert_string(blob)
+        self.assertEqual(blob, msg.get_payload(decode=True))
+
+    def test_handles_binary_utf8_decodable(self):
+        blob = b'\x32\x32'
+        msg = ud.convert_string(blob)
+        self.assertEqual(blob, msg.get_payload(decode=True))
+
+    def test_handle_headers(self):
+        text = "hi mom"
+        msg = ud.convert_string(text)
+        self.assertEqual(text, msg.get_payload(decode=False))