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# vi: ts=4 expandtab
#
# Copyright (C) 2009-2010 Canonical Ltd.
#
# Author: Scott Moser <scott.moser@canonical.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3, as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import email
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import encoders
import yaml
starts_with_mappings={
'#include' : 'text/x-include-url',
'#!' : 'text/x-shellscript',
'#cloud-config' : 'text/cloud-config',
'#upstart-job' : 'text/upstart-job',
'#part-handler' : 'text/part-handler',
'#cloud-boothook' : 'text/cloud-boothook',
'#cloud-config-archive' : 'text/cloud-config-archive',
}
# if 'str' is compressed return decompressed otherwise return it
def decomp_str(str):
import StringIO
import gzip
try:
uncomp = gzip.GzipFile(None,"rb",1,StringIO.StringIO(str)).read()
return(uncomp)
except:
return(str)
def do_include(str,parts):
import urllib
# is just a list of urls, one per line
# also support '#include <url here>'
for line in str.splitlines():
if line == "#include": continue
if line.startswith("#include"):
line = line[len("#include"):].lstrip()
if line.startswith("#"): continue
content = urllib.urlopen(line).read()
process_includes(email.message_from_string(decomp_str(content)),parts)
def explode_cc_archive(archive,parts):
for ent in yaml.load(archive):
# ent can be one of:
# dict { 'filename' : 'value' , 'content' : 'value', 'type' : 'value' }
# filename and type not be present
# or
# scalar(payload)
filename = 'part-%03d' % len(parts['content'])
def_type = "text/cloud-config"
if isinstance(ent,str):
content = ent
mtype = type_from_startswith(content,def_type)
else:
content = ent.get('content', '')
filename = ent.get('filename', filename)
mtype = ent.get('type', None)
if mtype == None:
mtype = type_from_startswith(payload,def_type)
print "adding %s,%s" % (filename, mtype)
parts['content'].append(content)
parts['names'].append(filename)
parts['types'].append(mtype)
def type_from_startswith(payload, default=None):
# slist is sorted longest first
slist = sorted(starts_with_mappings.keys(), key=lambda e: 0-len(e))
for sstr in slist:
if payload.startswith(sstr):
return(starts_with_mappings[sstr])
return default
def process_includes(msg,parts):
# parts is a dictionary of arrays
# parts['content']
# parts['names']
# parts['types']
for t in ( 'content', 'names', 'types' ):
if not parts.has_key(t):
parts[t]=[ ]
for part in msg.walk():
# multipart/* are just containers
if part.get_content_maintype() == 'multipart':
continue
payload = part.get_payload()
ctype = None
ctype_orig = part.get_content_type()
if ctype_orig == "text/plain":
ctype = type_from_startswith(payload)
if ctype is None:
ctype = ctype_orig
if ctype == 'text/x-include-url':
do_include(payload,parts)
continue
if ctype == "text/cloud-config-archive":
explode_cc_archive(payload,parts)
continue
filename = part.get_filename()
if not filename:
filename = 'part-%03d' % len(parts['content'])
parts['content'].append(payload)
parts['types'].append(ctype)
parts['names'].append(filename)
def parts2mime(parts):
outer = MIMEMultipart()
i = 0
while i < len(parts['content']):
if parts['types'][i] is None:
# No guess could be made, or the file is encoded (compressed), so
# use a generic bag-of-bits type.
ctype = 'application/octet-stream'
else: ctype = parts['types'][i]
maintype, subtype = ctype.split('/', 1)
if maintype == 'text':
msg = MIMEText(parts['content'][i], _subtype=subtype)
else:
msg = MIMEBase(maintype, subtype)
msg.set_payload(parts['content'][i])
# Encode the payload using Base64
encoders.encode_base64(msg)
# Set the filename parameter
msg.add_header('Content-Disposition', 'attachment',
filename=parts['names'][i])
outer.attach(msg)
i=i+1
return(outer.as_string())
# this is heavily wasteful, reads through userdata string input
def preprocess_userdata(data):
parts = { }
process_includes(email.message_from_string(decomp_str(data)),parts)
return(parts2mime(parts))
# callbacks is a dictionary with:
# { 'content-type': handler(data,content_type,filename,payload) }
def walk_userdata(str, callbacks, data = None):
partnum = 0
for part in email.message_from_string(str).walk():
# multipart/* are just containers
if part.get_content_maintype() == 'multipart':
continue
ctype = part.get_content_type()
if ctype is None:
ctype = 'application/octet-stream'
filename = part.get_filename()
if not filename:
filename = 'part-%03d' % partnum
if callbacks.has_key(ctype):
callbacks[ctype](data,ctype,filename,part.get_payload())
partnum = partnum+1
if __name__ == "__main__":
import sys
data = decomp_str(file(sys.argv[1]).read())
parts = { }
process_includes(email.message_from_string(data),parts)
print "#found %s parts" % len(parts['content'])
print parts2mime(parts)
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