cloud-init/cloudinit/config/cc_growpart.py
Scott Moser d09712ac24 add util.log_time helper
The reason for this is that more and more things I was wanting to be able to
see how long they took.  This puts that time logic into a single place.  It
also supports (by default) reading from /proc/uptime as the timing mechanism.

While that is almost certainly slower than time.time(), it does give 
millisecond granularity and is not affected by 'ntpdate' having
run in between the two events.
2013-07-30 14:23:10 -04:00

276 lines
8.2 KiB
Python

# vi: ts=4 expandtab
#
# Copyright (C) 2011 Canonical Ltd.
# Copyright (C) 2013 Hewlett-Packard Development Company, L.P.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Juerg Haefliger <juerg.haefliger@hp.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 = util.log_time(logfunc=log.debug, msg="resize_devices",
func=resize_devices, args=(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))