diff options
Diffstat (limited to 'cloudinit/config/cc_growpart.py')
| -rw-r--r-- | cloudinit/config/cc_growpart.py | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/cloudinit/config/cc_growpart.py b/cloudinit/config/cc_growpart.py new file mode 100644 index 00000000..b6e1fd37 --- /dev/null +++ b/cloudinit/config/cc_growpart.py @@ -0,0 +1,272 @@ +# vi: ts=4 expandtab +# +# Copyright (C) 2011 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 os +import os.path +import re +import stat + +from cloudinit import log as logging +from cloudinit.settings import PER_ALWAYS +from cloudinit import util + +frequency = PER_ALWAYS + +DEFAULT_CONFIG = { + 'mode': 'auto', + 'devices': ['/'], +} + + +def enum(**enums): + return type('Enum', (), enums) + + +RESIZE = enum(SKIPPED="SKIPPED", CHANGED="CHANGED", NOCHANGE="NOCHANGE", + FAILED="FAILED") + +LOG = logging.getLogger(__name__) + + +def resizer_factory(mode): + resize_class = None + if mode == "auto": + for (_name, resizer) in RESIZERS: + cur = resizer() + if cur.available(): + resize_class = cur + break + + if not resize_class: + raise ValueError("No resizers available") + + else: + mmap = {} + for (k, v) in RESIZERS: + mmap[k] = v + + if mode not in mmap: + raise TypeError("unknown resize mode %s" % mode) + + mclass = mmap[mode]() + if mclass.available(): + resize_class = mclass + + if not resize_class: + raise ValueError("mode %s not available" % mode) + + return resize_class + + +class ResizeFailedException(Exception): + pass + + +class ResizeParted(object): + def available(self): + myenv = os.environ.copy() + myenv['LANG'] = 'C' + + try: + (out, _err) = util.subp(["parted", "--help"], env=myenv) + if re.search(r"COMMAND.*resizepart\s+", out, re.DOTALL): + return True + + except util.ProcessExecutionError: + pass + return False + + def resize(self, diskdev, partnum, partdev): + before = get_size(partdev) + try: + util.subp(["parted", "resizepart", diskdev, partnum]) + except util.ProcessExecutionError as e: + raise ResizeFailedException(e) + + return (before, get_size(partdev)) + + +class ResizeGrowPart(object): + def available(self): + myenv = os.environ.copy() + myenv['LANG'] = 'C' + + try: + (out, _err) = util.subp(["growpart", "--help"], env=myenv) + if re.search(r"--update\s+", out, re.DOTALL): + return True + + except util.ProcessExecutionError: + pass + return False + + def resize(self, diskdev, partnum, partdev): + before = get_size(partdev) + try: + util.subp(["growpart", '--dry-run', diskdev, partnum]) + except util.ProcessExecutionError as e: + if e.exit_code != 1: + util.logexc(LOG, ("Failed growpart --dry-run for (%s, %s)" % + (diskdev, partnum))) + raise ResizeFailedException(e) + return (before, before) + + try: + util.subp(["growpart", diskdev, partnum]) + except util.ProcessExecutionError as e: + util.logexc(LOG, "Failed: growpart %s %s" % (diskdev, partnum)) + raise ResizeFailedException(e) + + return (before, get_size(partdev)) + + +def get_size(filename): + fd = os.open(filename, os.O_RDONLY) + try: + return os.lseek(fd, 0, os.SEEK_END) + finally: + os.close(fd) + + +def device_part_info(devpath): + # convert an entry in /dev/ to parent disk and partition number + + # input of /dev/vdb or /dev/disk/by-label/foo + # rpath is hopefully a real-ish path in /dev (vda, sdb..) + rpath = os.path.realpath(devpath) + + bname = os.path.basename(rpath) + syspath = "/sys/class/block/%s" % bname + + if not os.path.exists(syspath): + raise ValueError("%s had no syspath (%s)" % (devpath, syspath)) + + ptpath = os.path.join(syspath, "partition") + if not os.path.exists(ptpath): + raise TypeError("%s not a partition" % devpath) + + ptnum = util.load_file(ptpath).rstrip() + + # for a partition, real syspath is something like: + # /sys/devices/pci0000:00/0000:00:04.0/virtio1/block/vda/vda1 + rsyspath = os.path.realpath(syspath) + disksyspath = os.path.dirname(rsyspath) + + diskmajmin = util.load_file(os.path.join(disksyspath, "dev")).rstrip() + diskdevpath = os.path.realpath("/dev/block/%s" % diskmajmin) + + # diskdevpath has something like 253:0 + # and udev has put links in /dev/block/253:0 to the device name in /dev/ + return (diskdevpath, ptnum) + + +def devent2dev(devent): + if devent.startswith("/dev/"): + return devent + else: + result = util.get_mount_info(devent) + if not result: + raise ValueError("Could not determine device of '%s' % dev_ent") + return result[0] + + +def resize_devices(resizer, devices): + # returns a tuple of tuples containing (entry-in-devices, action, message) + info = [] + for devent in devices: + try: + blockdev = devent2dev(devent) + except ValueError as e: + info.append((devent, RESIZE.SKIPPED, + "unable to convert to device: %s" % e,)) + continue + + try: + statret = os.stat(blockdev) + except OSError as e: + info.append((devent, RESIZE.SKIPPED, + "stat of '%s' failed: %s" % (blockdev, e),)) + continue + + if not stat.S_ISBLK(statret.st_mode): + info.append((devent, RESIZE.SKIPPED, + "device '%s' not a block device" % blockdev,)) + continue + + try: + (disk, ptnum) = device_part_info(blockdev) + except (TypeError, ValueError) as e: + info.append((devent, RESIZE.SKIPPED, + "device_part_info(%s) failed: %s" % (blockdev, e),)) + continue + + try: + (old, new) = resizer.resize(disk, ptnum, blockdev) + if old == new: + info.append((devent, RESIZE.NOCHANGE, + "no change necessary (%s, %s)" % (disk, ptnum),)) + else: + info.append((devent, RESIZE.CHANGED, + "changed (%s, %s) from %s to %s" % + (disk, ptnum, old, new),)) + + except ResizeFailedException as e: + info.append((devent, RESIZE.FAILED, + "failed to resize: disk=%s, ptnum=%s: %s" % + (disk, ptnum, e),)) + + return info + + +def handle(_name, cfg, _cloud, log, _args): + if 'growpart' not in cfg: + log.debug("No 'growpart' entry in cfg. Using default: %s" % + DEFAULT_CONFIG) + cfg['growpart'] = DEFAULT_CONFIG + + mycfg = cfg.get('growpart') + if not isinstance(mycfg, dict): + log.warn("'growpart' in config was not a dict") + return + + mode = mycfg.get('mode', "auto") + if util.is_false(mode): + log.debug("growpart disabled: mode=%s" % mode) + return + + devices = util.get_cfg_option_list(cfg, "devices", ["/"]) + if not len(devices): + log.debug("growpart: empty device list") + return + + try: + resizer = resizer_factory(mode) + except (ValueError, TypeError) as e: + log.debug("growpart unable to find resizer for '%s': %s" % (mode, e)) + if mode != "auto": + raise e + return + + resized = resize_devices(resizer, devices) + for (entry, action, msg) in resized: + if action == RESIZE.CHANGED: + log.info("'%s' resized: %s" % (entry, msg)) + else: + log.debug("'%s' %s: %s" % (entry, action, msg)) + +RESIZERS = (('parted', ResizeParted), ('growpart', ResizeGrowPart)) |