# This file is part of cloud-init. See LICENSE file for license information.

"""Generate multi-part mime messages for user-data """

import argparse

import sys

from email.mime.multipart import MIMEMultipart

from email.mime.text import MIMEText

from cloudinit import log

from cloudinit.handlers import INCLUSION_TYPES_MAP

from . import addLogHandlerCLI

NAME = 'make-mime'

LOG = log.getLogger(NAME)

EPILOG = ("Example: make-mime -a config.yaml:cloud-config "

          "-a script.sh:x-shellscript > user-data")

def file_content_type(text):

    """ 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())

    except ValueError as e:

        raise argparse.ArgumentError(

            text, "Invalid value for %r" % (text)

        ) from e

def get_parser(parser=None):

    """Build or extend and arg parser for make-mime utility.

    @param parser: Optional existing ArgumentParser instance representing the

        subcommand which will be extended to support the args of this utility.

    @returns: ArgumentParser with proper argument configuration.

    """

    if not parser:

        parser = argparse.ArgumentParser()

    # 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')

    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 sorted([ctype.replace("text/", "") if strip_prefix else ctype

                   for ctype in INCLUSION_TYPES_MAP.values()])

def handle_args(name, args):

    """Create a multi-part MIME archive for use as user-data.  Optionally

       print out the list of supported content types of cloud-init.

    Also setup CLI log handlers to report to stderr since this is a development

    utility which should be run by a human on the CLI.

    @return 0 on success, 1 on failure.

    """

    addLogHandlerCLI(LOG, log.DEBUG if args.debug else log.WARNING)

    if args.list_types:

        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:

        sys.stderr.write("Invalid content-types, override with --force\n")

        return 1

    combined_message = MIMEMultipart()

    for msg in sub_messages:

        combined_message.attach(msg)

    print(combined_message)

    return 0

def main():

    args = get_parser().parse_args()

    return(handle_args(NAME, args))

if __name__ == '__main__':

    sys.exit(main())

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