99bbf6f217
if user data is of type text/cloud-boothook, or begins with
#cloud-boothook, then assume it to be code to be executed.
Boothooks are a very simple format. Basically, its a one line header
('#cloud-config\n') and then executable payload.
The executable payload is written to a file, then that file is executed
at the time it is read. The file is left in
/var/lib/cloud/data/boothooks
There is no "first-time-only" protection. If running only once is
desired, the boothook must handle that itself.
149 lines
4.6 KiB
Python
149 lines
4.6 KiB
Python
# vi: ts=4 expandtab
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#
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# Copyright (C) 2009-2010 Canonical Ltd.
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#
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# Author: Scott Moser <scott.moser@canonical.com>
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License version 3, as
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# published by the Free Software Foundation.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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import email
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from email.mime.multipart import MIMEMultipart
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from email.mime.text import MIMEText
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starts_with_mappings={
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'#include' : 'text/x-include-url',
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'#!' : 'text/x-shellscript',
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'#cloud-config' : 'text/cloud-config',
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'#upstart-job' : 'text/upstart-job',
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'#part-handler' : 'text/part-handler',
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'#cloud-boothook' : 'text/cloud-boothook'
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}
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# if 'str' is compressed return decompressed otherwise return it
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def decomp_str(str):
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import StringIO
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import gzip
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try:
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uncomp = gzip.GzipFile(None,"rb",1,StringIO.StringIO(str)).read()
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return(uncomp)
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except:
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return(str)
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def do_include(str,parts):
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import urllib
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# is just a list of urls, one per line
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for line in str.splitlines():
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if line == "#include": continue
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if line.startswith("#"): continue
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content = urllib.urlopen(line).read()
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process_includes(email.message_from_string(decomp_str(content)),parts)
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def process_includes(msg,parts):
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# parts is a dictionary of arrays
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# parts['content']
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# parts['names']
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# parts['types']
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for t in ( 'content', 'names', 'types' ):
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if not parts.has_key(t):
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parts[t]=[ ]
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for part in msg.walk():
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# multipart/* are just containers
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if part.get_content_maintype() == 'multipart':
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continue
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payload = part.get_payload()
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ctype = None
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for str, gtype in starts_with_mappings.items():
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if payload.startswith(str):
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ctype = gtype
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break
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if ctype is None:
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ctype = part.get_content_type()
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if ctype == 'text/x-include-url':
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do_include(payload,parts)
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continue
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filename = part.get_filename()
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if not filename:
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filename = 'part-%03d' % len(parts['content'])
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parts['content'].append(payload)
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parts['types'].append(ctype)
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parts['names'].append(filename)
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def parts2mime(parts):
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outer = MIMEMultipart()
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i = 0
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while i < len(parts['content']):
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if parts['types'][i] is None:
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# No guess could be made, or the file is encoded (compressed), so
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# use a generic bag-of-bits type.
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ctype = 'application/octet-stream'
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else: ctype = parts['types'][i]
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maintype, subtype = ctype.split('/', 1)
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if maintype == 'text':
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msg = MIMEText(parts['content'][i], _subtype=subtype)
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else:
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msg = MIMEBase(maintype, subtype)
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msg.set_payload(parts['content'][i])
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# Encode the payload using Base64
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encoders.encode_base64(msg)
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# Set the filename parameter
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msg.add_header('Content-Disposition', 'attachment',
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filename=parts['names'][i])
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outer.attach(msg)
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i=i+1
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return(outer.as_string())
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# this is heavily wasteful, reads through userdata string input
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def preprocess_userdata(data):
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parts = { }
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process_includes(email.message_from_string(decomp_str(data)),parts)
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return(parts2mime(parts))
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# callbacks is a dictionary with:
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# { 'content-type': handler(data,content_type,filename,payload) }
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def walk_userdata(str, callbacks, data = None):
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partnum = 0
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for part in email.message_from_string(str).walk():
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# multipart/* are just containers
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if part.get_content_maintype() == 'multipart':
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continue
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ctype = part.get_content_type()
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if ctype is None:
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ctype = 'application/octet-stream'
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filename = part.get_filename()
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if not filename:
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filename = 'part-%03d' % partnum
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if callbacks.has_key(ctype):
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callbacks[ctype](data,ctype,filename,part.get_payload())
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partnum = partnum+1
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if __name__ == "__main__":
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import sys
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data = decomp_str(file(sys.argv[1]).read())
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parts = { }
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process_includes(email.message_from_string(data),parts)
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print "#found %s parts" % len(parts['content'])
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print parts2mime(parts)
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