cloud-init/cloudinit/config/cc_mounts.py

415 lines
13 KiB
Python

# vi: ts=4 expandtab
#
# Copyright (C) 2009-2010 Canonical Ltd.
# Copyright (C) 2012 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/>.
from string import whitespace
import logging
import os.path
import re
from cloudinit import type_utils
from cloudinit import util
# Shortname matches 'sda', 'sda1', 'xvda', 'hda', 'sdb', xvdb, vda, vdd1, sr0
SHORTNAME_FILTER = r"^([x]{0,1}[shv]d[a-z][0-9]*|sr[0-9]+)$"
SHORTNAME = re.compile(SHORTNAME_FILTER)
WS = re.compile("[%s]+" % (whitespace))
FSTAB_PATH = "/etc/fstab"
LOG = logging.getLogger(__name__)
def is_mdname(name):
# return true if this is a metadata service name
if name in ["ami", "root", "swap"]:
return True
# names 'ephemeral0' or 'ephemeral1'
# 'ebs[0-9]' appears when '--block-device-mapping sdf=snap-d4d90bbc'
for enumname in ("ephemeral", "ebs"):
if name.startswith(enumname) and name.find(":") == -1:
return True
return False
def sanitize_devname(startname, transformer, log):
log.debug("Attempting to determine the real name of %s", startname)
# workaround, allow user to specify 'ephemeral'
# rather than more ec2 correct 'ephemeral0'
devname = startname
if devname == "ephemeral":
devname = "ephemeral0"
log.debug("Adjusted mount option from ephemeral to ephemeral0")
(blockdev, part) = util.expand_dotted_devname(devname)
if is_mdname(blockdev):
orig = blockdev
blockdev = transformer(blockdev)
if not blockdev:
return None
if not blockdev.startswith("/"):
blockdev = "/dev/%s" % blockdev
log.debug("Mapped metadata name %s to %s", orig, blockdev)
else:
if SHORTNAME.match(startname):
blockdev = "/dev/%s" % blockdev
return devnode_for_dev_part(blockdev, part)
def suggested_swapsize(memsize=None, maxsize=None, fsys=None):
# make a suggestion on the size of swap for this system.
if memsize is None:
memsize = util.read_meminfo()['total']
GB = 2 ** 30
sugg_max = 8 * GB
info = {'avail': 'na', 'max_in': maxsize, 'mem': memsize}
if fsys is None and maxsize is None:
# set max to 8GB default if no filesystem given
maxsize = sugg_max
elif fsys:
statvfs = os.statvfs(fsys)
avail = statvfs.f_frsize * statvfs.f_bfree
info['avail'] = avail
if maxsize is None:
# set to 25% of filesystem space
maxsize = min(int(avail / 4), sugg_max)
elif maxsize > ((avail * .9)):
# set to 90% of available disk space
maxsize = int(avail * .9)
elif maxsize is None:
maxsize = sugg_max
info['max'] = maxsize
formulas = [
# < 1G: swap = double memory
(1 * GB, lambda x: x * 2),
# < 2G: swap = 2G
(2 * GB, lambda x: 2 * GB),
# < 4G: swap = memory
(4 * GB, lambda x: x),
# < 16G: 4G
(16 * GB, lambda x: 4 * GB),
# < 64G: 1/2 M up to max
(64 * GB, lambda x: x / 2),
]
size = None
for top, func in formulas:
if memsize <= top:
size = min(func(memsize), maxsize)
# if less than 1/2 memory and not much, return 0
if size < (memsize / 2) and size < 4 * GB:
size = 0
break
break
if size is not None:
size = maxsize
info['size'] = size
MB = 2 ** 20
pinfo = {}
for k, v in info.items():
if isinstance(v, int):
pinfo[k] = "%s MB" % (v / MB)
else:
pinfo[k] = v
LOG.debug("suggest %(size)s swap for %(mem)s memory with '%(avail)s'"
" disk given max=%(max_in)s [max=%(max)s]'" % pinfo)
return size
def setup_swapfile(fname, size=None, maxsize=None):
"""
fname: full path string of filename to setup
size: the size to create. set to "auto" for recommended
maxsize: the maximum size
"""
tdir = os.path.dirname(fname)
if str(size).lower() == "auto":
try:
memsize = util.read_meminfo()['total']
except IOError as e:
LOG.debug("Not creating swap. failed to read meminfo")
return
util.ensure_dir(tdir)
size = suggested_swapsize(fsys=tdir, maxsize=maxsize,
memsize=memsize)
if not size:
LOG.debug("Not creating swap: suggested size was 0")
return
mbsize = str(int(size / (2 ** 20)))
msg = "creating swap file '%s' of %sMB" % (fname, mbsize)
try:
util.ensure_dir(tdir)
util.log_time(LOG.debug, msg, func=util.subp,
args=[['sh', '-c',
('rm -f "$1" && umask 0066 && '
'dd if=/dev/zero "of=$1" bs=1M "count=$2" && '
'mkswap "$1" || { r=$?; rm -f "$1"; exit $r; }'),
'setup_swap', fname, mbsize]])
except Exception as e:
raise IOError("Failed %s: %s" % (msg, e))
return fname
def handle_swapcfg(swapcfg):
"""handle the swap config, calling setup_swap if necessary.
return None or (filename, size)
"""
if not isinstance(swapcfg, dict):
LOG.warn("input for swap config was not a dict.")
return None
fname = swapcfg.get('filename', '/swap.img')
size = swapcfg.get('size', 0)
maxsize = swapcfg.get('maxsize', None)
if not (size and fname):
LOG.debug("no need to setup swap")
return
if os.path.exists(fname):
if not os.path.exists("/proc/swaps"):
LOG.debug("swap file %s existed. no /proc/swaps. Being safe.",
fname)
return fname
try:
for line in util.load_file("/proc/swaps").splitlines():
if line.startswith(fname + " "):
LOG.debug("swap file %s already in use.", fname)
return fname
LOG.debug("swap file %s existed, but not in /proc/swaps", fname)
except:
LOG.warn("swap file %s existed. Error reading /proc/swaps", fname)
return fname
try:
if isinstance(size, str) and size != "auto":
size = util.human2bytes(size)
if isinstance(maxsize, str):
maxsize = util.human2bytes(maxsize)
return setup_swapfile(fname=fname, size=size, maxsize=maxsize)
except Exception as e:
LOG.warn("failed to setup swap: %s", e)
return None
def handle(_name, cfg, cloud, log, _args):
# fs_spec, fs_file, fs_vfstype, fs_mntops, fs-freq, fs_passno
defvals = [None, None, "auto", "defaults,nobootwait", "0", "2"]
defvals = cfg.get("mount_default_fields", defvals)
# these are our default set of mounts
defmnts = [["ephemeral0", "/mnt", "auto", defvals[3], "0", "2"],
["swap", "none", "swap", "sw", "0", "0"]]
cfgmnt = []
if "mounts" in cfg:
cfgmnt = cfg["mounts"]
for i in range(len(cfgmnt)):
# skip something that wasn't a list
if not isinstance(cfgmnt[i], list):
log.warn("Mount option %s not a list, got a %s instead",
(i + 1), type_utils.obj_name(cfgmnt[i]))
continue
start = str(cfgmnt[i][0])
sanitized = sanitize_devname(start, cloud.device_name_to_device, log)
if sanitized is None:
log.debug("Ignorming nonexistant named mount %s", start)
continue
if sanitized != start:
log.debug("changed %s => %s" % (start, sanitized))
cfgmnt[i][0] = sanitized
# in case the user did not quote a field (likely fs-freq, fs_passno)
# but do not convert None to 'None' (LP: #898365)
for j in range(len(cfgmnt[i])):
if cfgmnt[i][j] is None:
continue
else:
cfgmnt[i][j] = str(cfgmnt[i][j])
for i in range(len(cfgmnt)):
# fill in values with defaults from defvals above
for j in range(len(defvals)):
if len(cfgmnt[i]) <= j:
cfgmnt[i].append(defvals[j])
elif cfgmnt[i][j] is None:
cfgmnt[i][j] = defvals[j]
# if the second entry in the list is 'None' this
# clears all previous entries of that same 'fs_spec'
# (fs_spec is the first field in /etc/fstab, ie, that device)
if cfgmnt[i][1] is None:
for j in range(i):
if cfgmnt[j][0] == cfgmnt[i][0]:
cfgmnt[j][1] = None
# for each of the "default" mounts, add them only if no other
# entry has the same device name
for defmnt in defmnts:
start = defmnt[0]
sanitized = sanitize_devname(start, cloud.device_name_to_device, log)
if sanitized is None:
log.debug("Ignoring nonexistant default named mount %s", start)
continue
if sanitized != start:
log.debug("changed default device %s => %s" % (start, sanitized))
defmnt[0] = sanitized
cfgmnt_has = False
for cfgm in cfgmnt:
if cfgm[0] == defmnt[0]:
cfgmnt_has = True
break
if cfgmnt_has:
log.debug(("Not including %s, already"
" previously included"), start)
continue
cfgmnt.append(defmnt)
# now, each entry in the cfgmnt list has all fstab values
# if the second field is None (not the string, the value) we skip it
actlist = []
for x in cfgmnt:
if x[1] is None:
log.debug("Skipping non-existent device named %s", x[0])
else:
actlist.append(x)
swapret = handle_swapcfg(cfg.get('swap', {}))
if swapret:
actlist.append([swapret, "none", "swap", "sw", "0", "0"])
if len(actlist) == 0:
log.debug("No modifications to fstab needed.")
return
comment = "comment=cloudconfig"
cc_lines = []
needswap = False
dirs = []
for line in actlist:
# write 'comment' in the fs_mntops, entry, claiming this
line[3] = "%s,%s" % (line[3], comment)
if line[2] == "swap":
needswap = True
if line[1].startswith("/"):
dirs.append(line[1])
cc_lines.append('\t'.join(line))
fstab_lines = []
for line in util.load_file(FSTAB_PATH).splitlines():
try:
toks = WS.split(line)
if toks[3].find(comment) != -1:
continue
except:
pass
fstab_lines.append(line)
fstab_lines.extend(cc_lines)
contents = "%s\n" % ('\n'.join(fstab_lines))
util.write_file(FSTAB_PATH, contents)
if needswap:
try:
util.subp(("swapon", "-a"))
except:
util.logexc(log, "Activating swap via 'swapon -a' failed")
for d in dirs:
try:
util.ensure_dir(d)
except:
util.logexc(log, "Failed to make '%s' config-mount", d)
try:
util.subp(("mount", "-a"))
except:
util.logexc(log, "Activating mounts via 'mount -a' failed")
def devnode_for_dev_part(device, partition):
"""
Find the name of the partition. While this might seem rather
straight forward, its not since some devices are '<device><partition>'
while others are '<device>p<partition>'. For example, /dev/xvda3 on EC2
will present as /dev/xvda3p1 for the first partition since /dev/xvda3 is
a block device.
"""
if not os.path.exists(device):
return None
short_name = os.path.basename(device)
sys_path = "/sys/block/%s" % short_name
if not os.path.exists(sys_path):
LOG.debug("did not find entry for %s in /sys/block", short_name)
return None
sys_long_path = sys_path + "/" + short_name
if partition is not None:
partition = str(partition)
if partition is None:
valid_mappings = [sys_long_path + "1", sys_long_path + "p1"]
elif partition != "0":
valid_mappings = [sys_long_path + "%s" % partition,
sys_long_path + "p%s" % partition]
else:
valid_mappings = []
for cdisk in valid_mappings:
if not os.path.exists(cdisk):
continue
dev_path = "/dev/%s" % os.path.basename(cdisk)
if os.path.exists(dev_path):
return dev_path
if partition is None or partition == "0":
return device
LOG.debug("Did not fine partition %s for device %s", partition, device)
return None