1 files changed, 71 insertions, 42 deletions
diff --git a/cloudinit/cmd/devel/make_mime.py b/cloudinit/cmd/devel/make_mime.py
index 4e6a5778..c7671a93 100755
--- a/cloudinit/cmd/devel/make_mime.py
+++ b/cloudinit/cmd/devel/make_mime.py
@@ -9,19 +9,44 @@ from email.mime.text import MIMEText
 
 from cloudinit import log
 from cloudinit.handlers import INCLUSION_TYPES_MAP
+
 from . import addLogHandlerCLI
 
-NAME = 'make-mime'
+NAME = "make-mime"
 LOG = log.getLogger(NAME)
-EPILOG = ("Example: make-mime -a config.yaml:cloud-config "
-          "-a script.sh:x-shellscript > user-data")
+EPILOG = (
+    "Example: make-mime -a config.yaml:cloud-config "
+    "-a script.sh:x-shellscript > user-data"
+)
+
+
+def create_mime_message(files):
+    sub_messages = []
+    errors = []
+    for i, (fh, filename, format_type) in enumerate(files):
+        contents = fh.read()
+        sub_message = MIMEText(contents, format_type, sys.getdefaultencoding())
+        sub_message.add_header(
+            "Content-Disposition", 'attachment; filename="%s"' % (filename)
+        )
+        content_type = sub_message.get_content_type().lower()
+        if content_type not in get_content_types():
+            msg = (
+                "content type %r for attachment %s " "may be incorrect!"
+            ) % (content_type, i + 1)
+            errors.append(msg)
+        sub_messages.append(sub_message)
+    combined_message = MIMEMultipart()
+    for msg in sub_messages:
+        combined_message.attach(msg)
+    return (combined_message, errors)
 
 
 def file_content_type(text):
-    """ Return file content type by reading the first line of the input. """
+    """Return file content type by reading the first line of the input."""
     try:
         filename, content_type = text.split(":", 1)
-        return (open(filename, 'r'), filename, content_type.strip())
+        return (open(filename, "r"), filename, content_type.strip())
     except ValueError as e:
         raise argparse.ArgumentError(
             text, "Invalid value for %r" % (text)
@@ -41,26 +66,43 @@ def get_parser(parser=None):
     # update the parser's doc and add an epilog to show an example
     parser.description = __doc__
     parser.epilog = EPILOG
-    parser.add_argument("-a", "--attach", dest="files", type=file_content_type,
-                        action='append', default=[],
-                        metavar="<file>:<content-type>",
-                        help=("attach the given file as the specified "
-                              "content-type"))
-    parser.add_argument('-l', '--list-types', action='store_true',
-                        default=False,
-                        help='List support cloud-init content types.')
-    parser.add_argument('-f', '--force', action='store_true',
-                        default=False,
-                        help='Ignore unknown content-type warnings')
+    parser.add_argument(
+        "-a",
+        "--attach",
+        dest="files",
+        type=file_content_type,
+        action="append",
+        default=[],
+        metavar="<file>:<content-type>",
+        help="attach the given file as the specified content-type",
+    )
+    parser.add_argument(
+        "-l",
+        "--list-types",
+        action="store_true",
+        default=False,
+        help="List support cloud-init content types.",
+    )
+    parser.add_argument(
+        "-f",
+        "--force",
+        action="store_true",
+        default=False,
+        help="Ignore unknown content-type warnings",
+    )
     return parser
 
 
 def get_content_types(strip_prefix=False):
-    """ Return a list of cloud-init supported content types.  Optionally
-        strip out the leading 'text/' of the type if strip_prefix=True.
+    """Return a list of cloud-init supported content types.  Optionally
+    strip out the leading 'text/' of the type if strip_prefix=True.
     """
-    return sorted([ctype.replace("text/", "") if strip_prefix else ctype
-                   for ctype in INCLUSION_TYPES_MAP.values()])
+    return sorted(
+        [
+            ctype.replace("text/", "") if strip_prefix else ctype
+            for ctype in INCLUSION_TYPES_MAP.values()
+        ]
+    )
 
 
 def handle_args(name, args):
@@ -77,37 +119,24 @@ def handle_args(name, args):
         print("\n".join(get_content_types(strip_prefix=True)))
         return 0
 
-    sub_messages = []
-    errors = []
-    for i, (fh, filename, format_type) in enumerate(args.files):
-        contents = fh.read()
-        sub_message = MIMEText(contents, format_type, sys.getdefaultencoding())
-        sub_message.add_header('Content-Disposition',
-                               'attachment; filename="%s"' % (filename))
-        content_type = sub_message.get_content_type().lower()
-        if content_type not in get_content_types():
-            level = "WARNING" if args.force else "ERROR"
-            msg = (level + ": content type %r for attachment %s "
-                   "may be incorrect!") % (content_type, i + 1)
-            sys.stderr.write(msg + '\n')
-            errors.append(msg)
-        sub_messages.append(sub_message)
-    if len(errors) and not args.force:
+    combined_message, errors = create_mime_message(args.files)
+    if errors:
+        level = "WARNING" if args.force else "ERROR"
+        for error in errors:
+            sys.stderr.write(f"{level}: {error}\n")
         sys.stderr.write("Invalid content-types, override with --force\n")
-        return 1
-    combined_message = MIMEMultipart()
-    for msg in sub_messages:
-        combined_message.attach(msg)
+        if not args.force:
+            return 1
     print(combined_message)
     return 0
 
 
 def main():
     args = get_parser().parse_args()
-    return(handle_args(NAME, args))
+    return handle_args(NAME, args)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     sys.exit(main())