Added gsutil/boto to depot_tools/third_party

third_party/boto/boto/utils.py

Index: third_party/boto/boto/utils.py
diff --git a/third_party/boto/boto/utils.py b/third_party/boto/boto/utils.py
new file mode 100644
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+++ b/third_party/boto/boto/utils.py
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+# Copyright (c) 2006-2012 Mitch Garnaat http://garnaat.org/
+# Copyright (c) 2010, Eucalyptus Systems, Inc.
+# Copyright (c) 2012 Amazon.com, Inc. or its affiliates.
+# All rights reserved.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish, dis-
+# tribute, sublicense, and/or sell copies of the Software, and to permit
+# persons to whom the Software is furnished to do so, subject to the fol-
+# lowing conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
+# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+#
+# Parts of this code were copied or derived from sample code supplied by AWS.
+# The following notice applies to that code.
+#
+#  This software code is made available "AS IS" without warranties of any
+#  kind.  You may copy, display, modify and redistribute the software
+#  code either by itself or as incorporated into your code; provided that
+#  you do not remove any proprietary notices.  Your use of this software
+#  code is at your own risk and you waive any claim against Amazon
+#  Digital Services, Inc. or its affiliates with respect to your use of
+#  this software code. (c) 2006 Amazon Digital Services, Inc. or its
+#  affiliates.
+
+"""
+Some handy utility functions used by several classes.
+"""
+
+import socket
+import urllib
+import urllib2
+import imp
+import subprocess
+import StringIO
+import time
+import logging.handlers
+import boto
+import boto.provider
+import tempfile
+import smtplib
+import datetime
+import re
+import email.mime.multipart
+import email.mime.base
+import email.mime.text
+import email.utils
+import email.encoders
+import gzip
+import base64
+try:
+    from hashlib import md5
+except ImportError:
+    from md5 import md5
+
+
+try:
+    import hashlib
+    _hashfn = hashlib.sha512
+except ImportError:
+    import md5
+    _hashfn = md5.md5
+
+from boto.compat import json
+
+# List of Query String Arguments of Interest
+qsa_of_interest = ['acl', 'cors', 'defaultObjectAcl', 'location', 'logging',
+                   'partNumber', 'policy', 'requestPayment', 'torrent',
+                   'versioning', 'versionId', 'versions', 'website',
+                   'uploads', 'uploadId', 'response-content-type',
+                   'response-content-language', 'response-expires',
+                   'response-cache-control', 'response-content-disposition',
+                   'response-content-encoding', 'delete', 'lifecycle',
+                   'tagging', 'restore',
+                   # storageClass is a QSA for buckets in Google Cloud Storage.
+                   # (StorageClass is associated to individual keys in S3, but
+                   # having it listed here should cause no problems because
+                   # GET bucket?storageClass is not part of the S3 API.)
+                   'storageClass',
+                   # websiteConfig is a QSA for buckets in Google Cloud Storage.
+                   'websiteConfig']
+
+
+_first_cap_regex = re.compile('(.)([A-Z][a-z]+)')
+_number_cap_regex = re.compile('([a-z])([0-9]+)')
+_end_cap_regex = re.compile('([a-z0-9])([A-Z])')
+
+
+def unquote_v(nv):
+    if len(nv) == 1:
+        return nv
+    else:
+        return (nv[0], urllib.unquote(nv[1]))
+
+
+def canonical_string(method, path, headers, expires=None,
+                     provider=None):
+    """
+    Generates the aws canonical string for the given parameters
+    """
+    if not provider:
+        provider = boto.provider.get_default()
+    interesting_headers = {}
+    for key in headers:
+        lk = key.lower()
+        if headers[key] != None and (lk in ['content-md5', 'content-type', 'date'] or
+                                     lk.startswith(provider.header_prefix)):
+            interesting_headers[lk] = str(headers[key]).strip()
+
+    # these keys get empty strings if they don't exist
+    if 'content-type' not in interesting_headers:
+        interesting_headers['content-type'] = ''
+    if 'content-md5' not in interesting_headers:
+        interesting_headers['content-md5'] = ''
+
+    # just in case someone used this.  it's not necessary in this lib.
+    if provider.date_header in interesting_headers:
+        interesting_headers['date'] = ''
+
+    # if you're using expires for query string auth, then it trumps date
+    # (and provider.date_header)
+    if expires:
+        interesting_headers['date'] = str(expires)
+
+    sorted_header_keys = sorted(interesting_headers.keys())
+
+    buf = "%s\n" % method
+    for key in sorted_header_keys:
+        val = interesting_headers[key]
+        if key.startswith(provider.header_prefix):
+            buf += "%s:%s\n" % (key, val)
+        else:
+            buf += "%s\n" % val
+
+    # don't include anything after the first ? in the resource...
+    # unless it is one of the QSA of interest, defined above
+    t = path.split('?')
+    buf += t[0]
+
+    if len(t) > 1:
+        qsa = t[1].split('&')
+        qsa = [a.split('=', 1) for a in qsa]
+        qsa = [unquote_v(a) for a in qsa if a[0] in qsa_of_interest]
+        if len(qsa) > 0:
+            qsa.sort(cmp=lambda x, y:cmp(x[0], y[0]))
+            qsa = ['='.join(a) for a in qsa]
+            buf += '?'
+            buf += '&'.join(qsa)
+
+    return buf
+
+
+def merge_meta(headers, metadata, provider=None):
+    if not provider:
+        provider = boto.provider.get_default()
+    metadata_prefix = provider.metadata_prefix
+    final_headers = headers.copy()
+    for k in metadata.keys():
+        if k.lower() in ['cache-control', 'content-md5', 'content-type',
+                         'content-encoding', 'content-disposition',
+                         'date', 'expires']:
+            final_headers[k] = metadata[k]
+        else:
+            final_headers[metadata_prefix + k] = metadata[k]
+
+    return final_headers
+
+
+def get_aws_metadata(headers, provider=None):
+    if not provider:
+        provider = boto.provider.get_default()
+    metadata_prefix = provider.metadata_prefix
+    metadata = {}
+    for hkey in headers.keys():
+        if hkey.lower().startswith(metadata_prefix):
+            val = urllib.unquote_plus(headers[hkey])
+            try:
+                metadata[hkey[len(metadata_prefix):]] = unicode(val, 'utf-8')
+            except UnicodeDecodeError:
+                metadata[hkey[len(metadata_prefix):]] = val
+            del headers[hkey]
+    return metadata
+
+
+def retry_url(url, retry_on_404=True, num_retries=10):
+    """
+    Retry a url.  This is specifically used for accessing the metadata
+    service on an instance.  Since this address should never be proxied
+    (for security reasons), we create a ProxyHandler with a NULL
+    dictionary to override any proxy settings in the environment.
+    """
+    for i in range(0, num_retries):
+        try:
+            proxy_handler = urllib2.ProxyHandler({})
+            opener = urllib2.build_opener(proxy_handler)
+            req = urllib2.Request(url)
+            r = opener.open(req)
+            result = r.read()
+            resp = urllib2.urlopen(req)
+            return resp.read()
+        except urllib2.HTTPError, e:
+            # in 2.6 you use getcode(), in 2.5 and earlier you use code
+            if hasattr(e, 'getcode'):
+                code = e.getcode()
+            else:
+                code = e.code
+            if code == 404 and not retry_on_404:
+                return ''
+        except urllib2.URLError, e:
+            raise e
+        except Exception, e:
+            pass
+        boto.log.exception('Caught exception reading instance data')
+        time.sleep(2 ** i)
+    boto.log.error('Unable to read instance data, giving up')
+    return ''
+
+
+def _get_instance_metadata(url, num_retries):
+    return LazyLoadMetadata(url, num_retries)
+
+
+class LazyLoadMetadata(dict):
+    def __init__(self, url, num_retries):
+        self._url = url
+        self._num_retries = num_retries
+        self._leaves = {}
+        self._dicts = []
+        data = boto.utils.retry_url(self._url, num_retries=self._num_retries)
+        if data:
+            fields = data.split('\n')
+            for field in fields:
+                if field.endswith('/'):
+                    key = field[0:-1]
+                    self._dicts.append(key)
+                else:
+                    p = field.find('=')
+                    if p > 0:
+                        key = field[p + 1:]
+                        resource = field[0:p] + '/openssh-key'
+                    else:
+                        key = resource = field
+                    self._leaves[key] = resource
+                self[key] = None
+
+    def _materialize(self):
+        for key in self:
+            self[key]
+
+    def __getitem__(self, key):
+        if key not in self:
+            # allow dict to throw the KeyError
+            return super(LazyLoadMetadata, self).__getitem__(key)
+
+        # already loaded
+        val = super(LazyLoadMetadata, self).__getitem__(key)
+        if val is not None:
+            return val
+
+        if key in self._leaves:
+            resource = self._leaves[key]
+            val = boto.utils.retry_url(self._url + urllib.quote(resource,
+                                                                safe="/:"),
+                                       num_retries=self._num_retries)
+            if val and val[0] == '{':
+                val = json.loads(val)
+            else:
+                p = val.find('\n')
+                if p > 0:
+                    val = val.split('\n')
+            self[key] = val
+        elif key in self._dicts:
+            self[key] = LazyLoadMetadata(self._url + key + '/',
+                                         self._num_retries)
+
+        return super(LazyLoadMetadata, self).__getitem__(key)
+
+    def get(self, key, default=None):
+        try:
+            return self[key]
+        except KeyError:
+            return default
+
+    def values(self):
+        self._materialize()
+        return super(LazyLoadMetadata, self).values()
+
+    def items(self):
+        self._materialize()
+        return super(LazyLoadMetadata, self).items()
+
+    def __str__(self):
+        self._materialize()
+        return super(LazyLoadMetadata, self).__str__()
+
+    def __repr__(self):
+        self._materialize()
+        return super(LazyLoadMetadata, self).__repr__()
+
+
+def get_instance_metadata(version='latest', url='http://169.254.169.254',
+                          timeout=None, num_retries=5):
+    """
+    Returns the instance metadata as a nested Python dictionary.
+    Simple values (e.g. local_hostname, hostname, etc.) will be
+    stored as string values.  Values such as ancestor-ami-ids will
+    be stored in the dict as a list of string values.  More complex
+    fields such as public-keys and will be stored as nested dicts.
+
+    If the timeout is specified, the connection to the specified url
+    will time out after the specified number of seconds.
+
+    """
+    if timeout is not None:
+        original = socket.getdefaulttimeout()
+        socket.setdefaulttimeout(timeout)
+    try:
+        return _get_instance_metadata('%s/%s/meta-data/' % (url, version),
+                                      num_retries=num_retries)
+    except urllib2.URLError, e:
+        return None
+    finally:
+        if timeout is not None:
+            socket.setdefaulttimeout(original)
+
+
+def get_instance_identity(version='latest', url='http://169.254.169.254',
+                          timeout=None, num_retries=5):
+    """
+    Returns the instance identity as a nested Python dictionary.
+    """
+    iid = {}
+    base_url = 'http://169.254.169.254/latest/dynamic/instance-identity'
+    if timeout is not None:
+        original = socket.getdefaulttimeout()
+        socket.setdefaulttimeout(timeout)
+    try:
+        data = retry_url(base_url, num_retries=num_retries)
+        fields = data.split('\n')
+        for field in fields:
+            val = retry_url(base_url + '/' + field + '/')
+            if val[0] == '{':
+                val = json.loads(val)
+            if field:
+                iid[field] = val
+        return iid
+    except urllib2.URLError, e:
+        return None
+    finally:
+        if timeout is not None:
+            socket.setdefaulttimeout(original)
+
+
+def get_instance_userdata(version='latest', sep=None,
+                          url='http://169.254.169.254'):
+    ud_url = '%s/%s/user-data' % (url, version)
+    user_data = retry_url(ud_url, retry_on_404=False)
+    if user_data:
+        if sep:
+            l = user_data.split(sep)
+            user_data = {}
+            for nvpair in l:
+                t = nvpair.split('=')
+                user_data[t[0].strip()] = t[1].strip()
+    return user_data
+
+ISO8601 = '%Y-%m-%dT%H:%M:%SZ'
+ISO8601_MS = '%Y-%m-%dT%H:%M:%S.%fZ'
+
+
+def get_ts(ts=None):
+    if not ts:
+        ts = time.gmtime()
+    return time.strftime(ISO8601, ts)
+
+
+def parse_ts(ts):
+    ts = ts.strip()
+    try:
+        dt = datetime.datetime.strptime(ts, ISO8601)
+        return dt
+    except ValueError:
+        dt = datetime.datetime.strptime(ts, ISO8601_MS)
+        return dt
+
+
+def find_class(module_name, class_name=None):
+    if class_name:
+        module_name = "%s.%s" % (module_name, class_name)
+    modules = module_name.split('.')
+    c = None
+
+    try:
+        for m in modules[1:]:
+            if c:
+                c = getattr(c, m)
+            else:
+                c = getattr(__import__(".".join(modules[0:-1])), m)
+        return c
+    except:
+        return None
+
+
+def update_dme(username, password, dme_id, ip_address):
+    """
+    Update your Dynamic DNS record with DNSMadeEasy.com
+    """
+    dme_url = 'https://www.dnsmadeeasy.com/servlet/updateip'
+    dme_url += '?username=%s&password=%s&id=%s&ip=%s'
+    s = urllib2.urlopen(dme_url % (username, password, dme_id, ip_address))
+    return s.read()
+
+
+def fetch_file(uri, file=None, username=None, password=None):
+    """
+    Fetch a file based on the URI provided. If you do not pass in a file pointer
+    a tempfile.NamedTemporaryFile, or None if the file could not be
+    retrieved is returned.
+    The URI can be either an HTTP url, or "s3://bucket_name/key_name"
+    """
+    boto.log.info('Fetching %s' % uri)
+    if file == None:
+        file = tempfile.NamedTemporaryFile()
+    try:
+        if uri.startswith('s3://'):
+            bucket_name, key_name = uri[len('s3://'):].split('/', 1)
+            c = boto.connect_s3(aws_access_key_id=username,
+                                aws_secret_access_key=password)
+            bucket = c.get_bucket(bucket_name)
+            key = bucket.get_key(key_name)
+            key.get_contents_to_file(file)
+        else:
+            if username and password:
+                passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
+                passman.add_password(None, uri, username, password)
+                authhandler = urllib2.HTTPBasicAuthHandler(passman)
+                opener = urllib2.build_opener(authhandler)
+                urllib2.install_opener(opener)
+            s = urllib2.urlopen(uri)
+            file.write(s.read())
+        file.seek(0)
+    except:
+        raise
+        boto.log.exception('Problem Retrieving file: %s' % uri)
+        file = None
+    return file
+
+
+class ShellCommand(object):
+
+    def __init__(self, command, wait=True, fail_fast=False, cwd=None):
+        self.exit_code = 0
+        self.command = command
+        self.log_fp = StringIO.StringIO()
+        self.wait = wait
+        self.fail_fast = fail_fast
+        self.run(cwd=cwd)
+
+    def run(self, cwd=None):
+        boto.log.info('running:%s' % self.command)
+        self.process = subprocess.Popen(self.command, shell=True,
+                                        stdin=subprocess.PIPE,
+                                        stdout=subprocess.PIPE,
+                                        stderr=subprocess.PIPE,
+                                        cwd=cwd)
+        if(self.wait):
+            while self.process.poll() == None:
+                time.sleep(1)
+                t = self.process.communicate()
+                self.log_fp.write(t[0])
+                self.log_fp.write(t[1])
+            boto.log.info(self.log_fp.getvalue())
+            self.exit_code = self.process.returncode
+
+            if self.fail_fast and self.exit_code != 0:
+                raise Exception("Command " + self.command + " failed with status " + self.exit_code)
+
+            return self.exit_code
+
+    def setReadOnly(self, value):
+        raise AttributeError
+
+    def getStatus(self):
+        return self.exit_code
+
+    status = property(getStatus, setReadOnly, None, 'The exit code for the command')
+
+    def getOutput(self):
+        return self.log_fp.getvalue()
+
+    output = property(getOutput, setReadOnly, None, 'The STDIN and STDERR output of the command')
+
+
+class AuthSMTPHandler(logging.handlers.SMTPHandler):
+    """
+    This class extends the SMTPHandler in the standard Python logging module
+    to accept a username and password on the constructor and to then use those
+    credentials to authenticate with the SMTP server.  To use this, you could
+    add something like this in your boto config file:
+
+    [handler_hand07]
+    class=boto.utils.AuthSMTPHandler
+    level=WARN
+    formatter=form07
+    args=('localhost', 'username', 'password', 'from@abc', ['user1@abc', 'user2@xyz'], 'Logger Subject')
+    """
+
+    def __init__(self, mailhost, username, password,
+                 fromaddr, toaddrs, subject):
+        """
+        Initialize the handler.
+
+        We have extended the constructor to accept a username/password
+        for SMTP authentication.
+        """
+        logging.handlers.SMTPHandler.__init__(self, mailhost, fromaddr,
+                                              toaddrs, subject)
+        self.username = username
+        self.password = password
+
+    def emit(self, record):
+        """
+        Emit a record.
+
+        Format the record and send it to the specified addressees.
+        It would be really nice if I could add authorization to this class
+        without having to resort to cut and paste inheritance but, no.
+        """
+        try:
+            port = self.mailport
+            if not port:
+                port = smtplib.SMTP_PORT
+            smtp = smtplib.SMTP(self.mailhost, port)
+            smtp.login(self.username, self.password)
+            msg = self.format(record)
+            msg = "From: %s\r\nTo: %s\r\nSubject: %s\r\nDate: %s\r\n\r\n%s" % (
+                            self.fromaddr,
+                            ','.join(self.toaddrs),
+                            self.getSubject(record),
+                            email.utils.formatdate(), msg)
+            smtp.sendmail(self.fromaddr, self.toaddrs, msg)
+            smtp.quit()
+        except (KeyboardInterrupt, SystemExit):
+            raise
+        except:
+            self.handleError(record)
+
+
+class LRUCache(dict):
+    """A dictionary-like object that stores only a certain number of items, and
+    discards its least recently used item when full.
+
+    >>> cache = LRUCache(3)
+    >>> cache['A'] = 0
+    >>> cache['B'] = 1
+    >>> cache['C'] = 2
+    >>> len(cache)
+    3
+
+    >>> cache['A']
+    0
+
+    Adding new items to the cache does not increase its size. Instead, the least
+    recently used item is dropped:
+
+    >>> cache['D'] = 3
+    >>> len(cache)
+    3
+    >>> 'B' in cache
+    False
+
+    Iterating over the cache returns the keys, starting with the most recently
+    used:
+
+    >>> for key in cache:
+    ...     print key
+    D
+    A
+    C
+
+    This code is based on the LRUCache class from Genshi which is based on
+    `Myghty <http://www.myghty.org>`_'s LRUCache from ``myghtyutils.util``,
+    written by Mike Bayer and released under the MIT license (Genshi uses the
+    BSD License).
+    """
+
+    class _Item(object):
+        def __init__(self, key, value):
+            self.previous = self.next = None
+            self.key = key
+            self.value = value
+
+        def __repr__(self):
+            return repr(self.value)
+
+    def __init__(self, capacity):
+        self._dict = dict()
+        self.capacity = capacity
+        self.head = None
+        self.tail = None
+
+    def __contains__(self, key):
+        return key in self._dict
+
+    def __iter__(self):
+        cur = self.head
+        while cur:
+            yield cur.key
+            cur = cur.next
+
+    def __len__(self):
+        return len(self._dict)
+
+    def __getitem__(self, key):
+        item = self._dict[key]
+        self._update_item(item)
+        return item.value
+
+    def __setitem__(self, key, value):
+        item = self._dict.get(key)
+        if item is None:
+            item = self._Item(key, value)
+            self._dict[key] = item
+            self._insert_item(item)
+        else:
+            item.value = value
+            self._update_item(item)
+            self._manage_size()
+
+    def __repr__(self):
+        return repr(self._dict)
+
+    def _insert_item(self, item):
+        item.previous = None
+        item.next = self.head
+        if self.head is not None:
+            self.head.previous = item
+        else:
+            self.tail = item
+        self.head = item
+        self._manage_size()
+
+    def _manage_size(self):
+        while len(self._dict) > self.capacity:
+            del self._dict[self.tail.key]
+            if self.tail != self.head:
+                self.tail = self.tail.previous
+                self.tail.next = None
+            else:
+                self.head = self.tail = None
+
+    def _update_item(self, item):
+        if self.head == item:
+            return
+
+        previous = item.previous
+        previous.next = item.next
+        if item.next is not None:
+            item.next.previous = previous
+        else:
+            self.tail = previous
+
+        item.previous = None
+        item.next = self.head
+        self.head.previous = self.head = item
+
+
+class Password(object):
+    """
+    Password object that stores itself as hashed.
+    Hash defaults to SHA512 if available, MD5 otherwise.
+    """
+    hashfunc = _hashfn
+
+    def __init__(self, str=None, hashfunc=None):
+        """
+        Load the string from an initial value, this should be the
+        raw hashed password.
+        """
+        self.str = str
+        if hashfunc:
+           self.hashfunc = hashfunc
+
+    def set(self, value):
+        self.str = self.hashfunc(value).hexdigest()
+
+    def __str__(self):
+        return str(self.str)
+
+    def __eq__(self, other):
+        if other == None:
+            return False
+        return str(self.hashfunc(other).hexdigest()) == str(self.str)
+
+    def __len__(self):
+        if self.str:
+            return len(self.str)
+        else:
+            return 0
+
+
+def notify(subject, body=None, html_body=None, to_string=None,
+           attachments=None, append_instance_id=True):
+    attachments = attachments or []
+    if append_instance_id:
+        subject = "[%s] %s" % (boto.config.get_value("Instance", "instance-id"), subject)
+    if not to_string:
+        to_string = boto.config.get_value('Notification', 'smtp_to', None)
+    if to_string:
+        try:
+            from_string = boto.config.get_value('Notification', 'smtp_from', 'boto')
+            msg = email.mime.multipart.MIMEMultipart()
+            msg['From'] = from_string
+            msg['Reply-To'] = from_string
+            msg['To'] = to_string
+            msg['Date'] = email.utils.formatdate(localtime=True)
+            msg['Subject'] = subject
+
+            if body:
+                msg.attach(email.mime.text.MIMEText(body))
+
+            if html_body:
+                part = email.mime.base.MIMEBase('text', 'html')
+                part.set_payload(html_body)
+                email.encoders.encode_base64(part)
+                msg.attach(part)
+
+            for part in attachments:
+                msg.attach(part)
+
+            smtp_host = boto.config.get_value('Notification', 'smtp_host', 'localhost')
+
+            # Alternate port support
+            if boto.config.get_value("Notification", "smtp_port"):
+                server = smtplib.SMTP(smtp_host, int(boto.config.get_value("Notification", "smtp_port")))
+            else:
+                server = smtplib.SMTP(smtp_host)
+
+            # TLS support
+            if boto.config.getbool("Notification", "smtp_tls"):
+                server.ehlo()
+                server.starttls()
+                server.ehlo()
+            smtp_user = boto.config.get_value('Notification', 'smtp_user', '')
+            smtp_pass = boto.config.get_value('Notification', 'smtp_pass', '')
+            if smtp_user:
+                server.login(smtp_user, smtp_pass)
+            server.sendmail(from_string, to_string, msg.as_string())
+            server.quit()
+        except:
+            boto.log.exception('notify failed')
+
+
+def get_utf8_value(value):
+    if not isinstance(value, str) and not isinstance(value, unicode):
+        value = str(value)
+    if isinstance(value, unicode):
+        return value.encode('utf-8')
+    else:
+        return value
+
+
+def mklist(value):
+    if not isinstance(value, list):
+        if isinstance(value, tuple):
+            value = list(value)
+        else:
+            value = [value]
+    return value
+
+
+def pythonize_name(name):
+    """Convert camel case to a "pythonic" name.
+
+    Examples::
+
+        pythonize_name('CamelCase') -> 'camel_case'
+        pythonize_name('already_pythonized') -> 'already_pythonized'
+        pythonize_name('HTTPRequest') -> 'http_request'
+        pythonize_name('HTTPStatus200Ok') -> 'http_status_200_ok'
+        pythonize_name('UPPER') -> 'upper'
+        pythonize_name('') -> ''
+
+    """
+    s1 = _first_cap_regex.sub(r'\1_\2', name)
+    s2 = _number_cap_regex.sub(r'\1_\2', s1)
+    return _end_cap_regex.sub(r'\1_\2', s2).lower()
+
+
+def write_mime_multipart(content, compress=False, deftype='text/plain', delimiter=':'):
+    """Description:
+    :param content: A list of tuples of name-content pairs. This is used
+    instead of a dict to ensure that scripts run in order
+    :type list of tuples:
+
+    :param compress: Use gzip to compress the scripts, defaults to no compression
+    :type bool:
+
+    :param deftype: The type that should be assumed if nothing else can be figured out
+    :type str:
+
+    :param delimiter: mime delimiter
+    :type str:
+
+    :return: Final mime multipart
+    :rtype: str:
+    """
+    wrapper = email.mime.multipart.MIMEMultipart()
+    for name, con in content:
+        definite_type = guess_mime_type(con, deftype)
+        maintype, subtype = definite_type.split('/', 1)
+        if maintype == 'text':
+            mime_con = email.mime.text.MIMEText(con, _subtype=subtype)
+        else:
+            mime_con = email.mime.base.MIMEBase(maintype, subtype)
+            mime_con.set_payload(con)
+            # Encode the payload using Base64
+            email.encoders.encode_base64(mime_con)
+        mime_con.add_header('Content-Disposition', 'attachment', filename=name)
+        wrapper.attach(mime_con)
+    rcontent = wrapper.as_string()
+
+    if compress:
+        buf = StringIO.StringIO()
+        gz = gzip.GzipFile(mode='wb', fileobj=buf)
+        try:
+            gz.write(rcontent)
+        finally:
+            gz.close()
+        rcontent = buf.getvalue()
+
+    return rcontent
+
+
+def guess_mime_type(content, deftype):
+    """Description: Guess the mime type of a block of text
+    :param content: content we're finding the type of
+    :type str:
+
+    :param deftype: Default mime type
+    :type str:
+
+    :rtype: <type>:
+    :return: <description>
+    """
+    #Mappings recognized by cloudinit
+    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'
+    }
+    rtype = deftype
+    for possible_type, mimetype in starts_with_mappings.items():
+        if content.startswith(possible_type):
+            rtype = mimetype
+            break
+    return(rtype)
+
+
+def compute_md5(fp, buf_size=8192, size=None):
+    """
+    Compute MD5 hash on passed file and return results in a tuple of values.
+
+    :type fp: file
+    :param fp: File pointer to the file to MD5 hash.  The file pointer
+               will be reset to its current location before the
+               method returns.
+
+    :type buf_size: integer
+    :param buf_size: Number of bytes per read request.
+
+    :type size: int
+    :param size: (optional) The Maximum number of bytes to read from
+                 the file pointer (fp). This is useful when uploading
+                 a file in multiple parts where the file is being
+                 split inplace into different parts. Less bytes may
+                 be available.
+
+    :rtype: tuple
+    :return: A tuple containing the hex digest version of the MD5 hash
+             as the first element, the base64 encoded version of the
+             plain digest as the second element and the data size as
+             the third element.
+    """
+    return compute_hash(fp, buf_size, size, hash_algorithm=md5)
+
+
+def compute_hash(fp, buf_size=8192, size=None, hash_algorithm=md5):
+    hash_obj = hash_algorithm()
+    spos = fp.tell()
+    if size and size < buf_size:
+        s = fp.read(size)
+    else:
+        s = fp.read(buf_size)
+    while s:
+        hash_obj.update(s)
+        if size:
+            size -= len(s)
+            if size <= 0:
+                break
+        if size and size < buf_size:
+            s = fp.read(size)
+        else:
+            s = fp.read(buf_size)
+    hex_digest = hash_obj.hexdigest()
+    base64_digest = base64.encodestring(hash_obj.digest())
+    if base64_digest[-1] == '\n':
+        base64_digest = base64_digest[0:-1]
+    # data_size based on bytes read.
+    data_size = fp.tell() - spos
+    fp.seek(spos)
+    return (hex_digest, base64_digest, data_size)