1 # Copyright 2017 The Chromium OS Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 import logging 6 import os 7 import sys 8 9 import common 10 from autotest_lib.client.bin import utils 11 from autotest_lib.client.common_lib import error 12 from autotest_lib.site_utils.lxc import constants 13 from autotest_lib.site_utils.lxc import lxc 14 from autotest_lib.site_utils.lxc import utils as lxc_utils 15 from autotest_lib.site_utils.lxc.container import Container 16 17 18 class BaseImage(object): 19 """A class that manages a base container. 20 21 Instantiating this class will cause it to search for a base container under 22 the given path and name. If one is found, the class adopts it. If not, the 23 setup() method needs to be called, to download and install a new base 24 container. 25 26 The actual base container can be obtained by calling the get() method. 27 28 Calling cleanup() will delete the base container along with all of its 29 associated snapshot clones. 30 """ 31 32 def __init__(self, 33 container_path=constants.DEFAULT_CONTAINER_PATH, 34 base_name=constants.BASE): 35 """Creates a new BaseImage. 36 37 If a valid base container already exists on this machine, the BaseImage 38 adopts it. Otherwise, setup needs to be called to download a base and 39 install a base container. 40 41 @param container_path: The LXC path for the base container. 42 @param base_name: The base container name. 43 """ 44 self.container_path = container_path 45 self.base_name = base_name 46 try: 47 base_container = Container.create_from_existing_dir( 48 container_path, base_name); 49 base_container.refresh_status() 50 self.base_container = base_container 51 except error.ContainerError as e: 52 self.base_container = None 53 self.base_container_error = e 54 55 56 def setup(self, name=None, force_delete=False): 57 """Download and setup the base container. 58 59 @param name: Name of the base container, defaults to the name passed to 60 the constructor. If a different name is provided, that 61 name overrides the name originally passed to the 62 constructor. 63 @param force_delete: True to force to delete existing base container. 64 This action will destroy all running test 65 containers. Default is set to False. 66 """ 67 if name is not None: 68 self.base_name = name 69 70 if not self.container_path: 71 raise error.ContainerError( 72 'You must set a valid directory to store containers in ' 73 'global config "AUTOSERV/ container_path".') 74 75 if not os.path.exists(self.container_path): 76 os.makedirs(self.container_path) 77 78 if self.base_container and not force_delete: 79 logging.error( 80 'Base container already exists. Set force_delete to True ' 81 'to force to re-stage base container. Note that this ' 82 'action will destroy all running test containers') 83 # Set proper file permission. base container in moblab may have 84 # owner of not being root. Force to update the folder's owner. 85 self._set_root_owner() 86 return 87 88 # Destroy existing base container if exists. 89 if self.base_container: 90 self.cleanup() 91 92 try: 93 self._download_and_install_base_container() 94 self._set_root_owner() 95 except: 96 # Clean up if something went wrong. 97 base_path = os.path.join(self.container_path, self.base_name) 98 if lxc_utils.path_exists(base_path): 99 exc_info = sys.exc_info() 100 container = Container.create_from_existing_dir( 101 self.container_path, self.base_name) 102 # Attempt destroy. Log but otherwise ignore errors. 103 try: 104 container.destroy() 105 except error.CmdError as e: 106 logging.error(e) 107 # Raise the cached exception with original backtrace. 108 raise exc_info[0], exc_info[1], exc_info[2] 109 else: 110 raise 111 else: 112 self.base_container = Container.create_from_existing_dir( 113 self.container_path, self.base_name) 114 115 116 def cleanup(self): 117 """Destroys the base container. 118 119 This operation will also destroy all snapshot clones of the base 120 container. 121 """ 122 # Find and delete clones first. 123 for clone in self._find_clones(): 124 clone.destroy() 125 base = Container.create_from_existing_dir(self.container_path, 126 self.base_name) 127 base.destroy() 128 129 130 def get(self): 131 """Returns the base container. 132 133 @raise ContainerError: If the base image is invalid or missing. 134 """ 135 if self.base_container is None: 136 raise self.base_container_error 137 else: 138 return self.base_container 139 140 141 def _download_and_install_base_container(self): 142 """Downloads the base image, untars and configures it.""" 143 base_path = os.path.join(self.container_path, self.base_name) 144 tar_path = os.path.join(self.container_path, 145 '%s.tar.xz' % self.base_name) 146 147 # Force cleanup of any previously downloaded/installed base containers. 148 # This ensures a clean setup of the new base container. 149 # 150 # TODO(kenobi): Add a check to ensure that the base container doesn't 151 # get deleted while snapshot clones exist (otherwise running tests might 152 # get disrupted). 153 path_to_cleanup = [tar_path, base_path] 154 for path in path_to_cleanup: 155 if os.path.exists(path): 156 utils.run('sudo rm -rf "%s"' % path) 157 container_url = constants.CONTAINER_BASE_URL_FMT % self.base_name 158 lxc.download_extract(container_url, tar_path, self.container_path) 159 # Remove the downloaded container tar file. 160 utils.run('sudo rm "%s"' % tar_path) 161 162 # Update container config with container_path from global config. 163 config_path = os.path.join(base_path, 'config') 164 rootfs_path = os.path.join(base_path, 'rootfs') 165 utils.run(('sudo sed ' 166 '-i "s|\(lxc\.rootfs[[:space:]]*=\).*$|\\1 {rootfs}|" ' 167 '"{config}"').format(rootfs=rootfs_path, 168 config=config_path)) 169 170 def _set_root_owner(self): 171 """Changes the container group and owner to root. 172 173 This is necessary because we currently run privileged containers. 174 """ 175 # TODO(dshi): Change root to current user when test container can be 176 # unprivileged container. 177 base_path = os.path.join(self.container_path, self.base_name) 178 utils.run('sudo chown -R root "%s"' % base_path) 179 utils.run('sudo chgrp -R root "%s"' % base_path) 180 181 182 def _find_clones(self): 183 """Finds snapshot clones of the current base container.""" 184 snapshot_file = os.path.join(self.container_path, 185 self.base_name, 186 'lxc_snapshots') 187 if not lxc_utils.path_exists(snapshot_file): 188 return 189 cmd = 'sudo cat %s' % snapshot_file 190 clone_info = [line.strip() 191 for line in utils.run(cmd).stdout.splitlines()] 192 # lxc_snapshots contains pairs of lines (lxc_path, container_name). 193 for i in range(0, len(clone_info), 2): 194 lxc_path = clone_info[i] 195 name = clone_info[i+1] 196 yield Container.create_from_existing_dir(lxc_path, name) 197
