rwlaunchpad/plugins/rwlaunchpadtasklet/rift/package/cloud_init.py

   1
   2 #
   3 #   Copyright 2016 RIFT.IO Inc
   4 #
   5 #   Licensed under the Apache License, Version 2.0 (the "License");
   6 #   you may not use this file except in compliance with the License.
   7 #   You may obtain a copy of the License at
   8 #
   9 #       http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 #   Unless required by applicable law or agreed to in writing, software
  12 #   distributed under the License is distributed on an "AS IS" BASIS,
  13 #   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 #   See the License for the specific language governing permissions and
  15 #   limitations under the License.
  16 #
  17
  18 import re
  19 import os.path
  20
  21 from . import package
  22
  23
  24 class CloudInitExtractionError(Exception):
  25     pass
  26
  27
  28 class PackageCloudInitExtractor(object):
  29     """ This class is reponsible for extracting cloud_init scripts to the correct directory
  30     """
  31
  32     SCRIPT_REGEX = "{prefix}/?cloud_init/(?P<script_name>[^/]+)$"
  33
  34     def __init__(self, log):
  35         self._log = log
  36
  37     @classmethod
  38     def package_script_files(cls, package):
  39         script_file_map = {}
  40
  41         for file_name in package.files:
  42             match = re.match(
  43                     cls.SCRIPT_REGEX.format(prefix=package.prefix),
  44                     file_name,
  45                     )
  46             if match is None:
  47                 continue
  48
  49             script_name = match.group("script_name")
  50             script_file_map[script_name] = file_name
  51
  52         return script_file_map
  53
  54     def read_script(self, pkg, filename):
  55         descriptor_id = pkg.descriptor_id
  56         script_files = PackageCloudInitExtractor.package_script_files(pkg)
  57
  58         for script_name, script_file in script_files.items():
  59             if script_name == filename:
  60                 self._log.debug("Found %s script file in package at %s", filename, script_file)
  61
  62                 try:
  63                     with pkg.open(script_file) as f:
  64                         userdata = f.read()
  65                         self._log.info("cloud_init read from file %s", userdata)
  66                         # File contents are read in binary string, decode to regular string and return
  67                         return userdata.decode()
  68                 except package.ExtractError as e:
  69                     raise CloudInitExtractionError("Failed to extract script %s" % script_name) from e
  70
  71         # If we've reached this point but not found a matching cloud_init script,
  72         # raise an Exception, since we got here only because there was supposed
  73         # to be a cloud_init_file in the VDU
  74         errmsg = "No cloud-init config file found in the descriptor package"
  75         self._log.error(errmsg)
  76         raise CloudInitExtractionError(errmsg)