Do not set the mime-type for userdata

We set the mime-type to  'x-shellscript' for all
single userdata when user_data_format='SOFTWARE_CONFIG',
it's incorrect, for example, if user create a server
with a cloud-config userdata, we will set the mime-type to
'x-shellscript', then cloud-init will consume the userdata
as a shellscript and fail to execute.

This change will improve this by not setting the mime-type
and letting cloud-init figure it out from the first line
in the file.

Closes-Bug: #1643739
Change-Id: If026884a95c58bb81a0f04ab415909011b1a5414

heat/engine/clients/os/nova.py

@@ -325,7 +325,9 @@ class NovaClientPlugin(client_plugin.ClientPlugin):
                 subtype = os.path.splitext(filename)[0]
             if content is None:
                 content = ''
-            msg = text.MIMEText(content, _subtype=subtype)
+            msg = (text.MIMEText(content, _subtype=subtype)
+                   if subtype else text.MIMEText(content))
+
             msg.add_header('Content-Disposition', 'attachment',
                            filename=filename)
             return msg
@@ -359,7 +361,6 @@ echo -e '%s\tALL=(ALL)\tNOPASSWD: ALL' >> /etc/sudoers
                        (cloudinit_boothook, 'boothook.sh', 'cloud-boothook'),
                        (read_cloudinit_file('part_handler.py'),
                         'part-handler.py')]
-
         if is_cfntools:
             attachments.append((userdata, 'cfn-userdata', 'x-cfninitdata'))
         elif is_software_config:
@@ -376,7 +377,7 @@ echo -e '%s\tALL=(ALL)\tNOPASSWD: ALL' >> /etc/sudoers
                                         part.get_filename(),
                                         part.get_content_subtype()))
             else:
-                attachments.append((userdata, 'userdata', 'x-shellscript'))
+                attachments.append((userdata, ''))
 
         if is_cfntools:
             attachments.append((read_cloudinit_file('loguserdata.py'),

heat_integrationtests/scenario/templates/test_server_signal.yaml

@@ -23,6 +23,9 @@ parameters:
   dns_servers:
     type: comma_delimited_list
     default: ["8.8.8.8", "8.8.4.4"]
+  user_data_format:
+    type: string
+    default: RAW
 resources:
   sg:
     type: OS::Neutron::SecurityGroup
@@ -76,7 +79,7 @@ resources:
       - subnet: {get_resource: subnet}
       security_groups:
       - {get_resource: sg}
-      user_data_format: RAW
+      user_data_format: {get_param: user_data_format}
       user_data:
         str_replace:
           template: |

heat_integrationtests/scenario/test_server_signal.py

@@ -20,13 +20,15 @@ from heat_integrationtests.scenario import scenario_base
 class ServerSignalIntegrationTest(scenario_base.ScenarioTestsBase):
     """Test a server in a created network can signal to heat."""
 
-    def test_server_signal(self):
+    def _test_server_signal(self, user_data_format='RAW',
+                            image=None):
         """Check a server in a created network can signal to heat."""
         parameters = {
             'key_name': self.keypair_name,
             'flavor': self.conf.minimal_instance_type,
-            'image': self.conf.minimal_image_ref,
+            'image': image,
             'timeout': self.conf.build_timeout,
+            'user_data_format': user_data_format
         }
 
         # Launch stack
@@ -72,3 +74,12 @@ class ServerSignalIntegrationTest(scenario_base.ScenarioTestsBase):
             self._log_console_output(servers=[server])
             self.fail(
                 "Timed out waiting for %s to become reachable" % server_ip)
+
+    def test_server_signal_userdata_format_raw(self):
+        self._test_server_signal(image=self.conf.minimal_image_ref)
+
+    def test_server_signal_userdata_format_software_config(self):
+        if not self.conf.image_ref:
+            raise self.skipException("No image configured to test")
+        self._test_server_signal(user_data_format='SOFTWARE_CONFIG',
+                                 image=self.conf.image_ref)