Current File : //lib/python3/dist-packages/cloudinit/config/cc_mounts.py
# 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 file is part of cloud-init. See LICENSE file for license information.
"""Mounts: Configure mount points and swap files"""
import logging
import math
import os
import re
from logging import Logger
from string import whitespace
from textwrap import dedent
from cloudinit import subp, type_utils, util
from cloudinit.cloud import Cloud
from cloudinit.config import Config
from cloudinit.config.schema import MetaSchema, get_meta_doc
from cloudinit.settings import PER_INSTANCE
MODULE_DESCRIPTION = """\
This module can add or remove mountpoints from ``/etc/fstab`` as well as
configure swap. The ``mounts`` config key takes a list of fstab entries to add.
Each entry is specified as a list of ``[ fs_spec, fs_file, fs_vfstype,
fs_mntops, fs-freq, fs_passno ]``. For more information on these options,
consult the manual for ``/etc/fstab``. When specifying the ``fs_spec``, if the
device name starts with one of ``xvd``, ``sd``, ``hd``, or ``vd``, the leading
``/dev`` may be omitted.
Any mounts that do not appear to either an attached block device or network
resource will be skipped with a log like "Ignoring nonexistent mount ...".
Cloud-init will attempt to add the following mount directives if available and
unconfigured in `/etc/fstab`::
mounts:
- ["ephemeral0", "/mnt", "auto",\
"defaults,nofail,x-systemd.requires=cloud-init.service", "0", "2"]
- ["swap", "none", "swap", "sw", "0", "0"]
In order to remove a previously listed mount, an entry can be added to
the `mounts` list containing ``fs_spec`` for the device to be removed but no
mountpoint (i.e. ``[ swap ]`` or ``[ swap, null ]``).
The ``mount_default_fields`` config key allows default options to be specified
for the values in a ``mounts`` entry that are not specified, aside from the
``fs_spec`` and the ``fs_file``. If specified, this must be a list containing 6
values. It defaults to::
mount_default_fields: [none, none, "auto",\
"defaults,nofail,x-systemd.requires=cloud-init.service", "0", "2"]
Non-systemd init systems will vary in ``mount_default_fields``.
Swap files can be configured by setting the path to the swap file to create
with ``filename``, the size of the swap file with ``size`` maximum size of
the swap file if using an ``size: auto`` with ``maxsize``. By default no
swap file is created.
"""
example = dedent(
"""\
# Mount ephemeral0 with "noexec" flag, /dev/sdc with mount_default_fields,
# and /dev/xvdh with custom fs_passno "0" to avoid fsck on the mount.
# Also provide an automatically sized swap with a max size of 10485760
# bytes.
mounts:
- [ /dev/ephemeral0, /mnt, auto, "defaults,noexec" ]
- [ sdc, /opt/data ]
- [ xvdh, /opt/data, auto, "defaults,nofail", "0", "0" ]
mount_default_fields: [None, None, auto, "defaults,nofail", "0", "2"]
swap:
filename: /my/swapfile
size: auto
maxsize: 10485760
"""
)
distros = ["all"]
meta: MetaSchema = {
"id": "cc_mounts",
"name": "Mounts",
"title": "Configure mount points and swap files",
"description": MODULE_DESCRIPTION,
"distros": distros,
"examples": [
example,
dedent(
"""\
# Create a 2 GB swap file at /swapfile using human-readable values
swap:
filename: /swapfile
size: 2G
maxsize: 2G
"""
),
],
"frequency": PER_INSTANCE,
"activate_by_schema_keys": [],
}
__doc__ = get_meta_doc(meta)
# Shortname matches 'sda', 'sda1', 'xvda', 'hda', 'sdb', xvdb, vda, vdd1, sr0
DEVICE_NAME_FILTER = r"^([x]{0,1}[shv]d[a-z][0-9]*|sr[0-9]+)$"
DEVICE_NAME_RE = re.compile(DEVICE_NAME_FILTER)
# Name matches 'server:/path'
NETWORK_NAME_FILTER = r"^.+:.*"
NETWORK_NAME_RE = re.compile(NETWORK_NAME_FILTER)
WS = re.compile("[%s]+" % (whitespace))
FSTAB_PATH = "/etc/fstab"
MNT_COMMENT = "comment=cloudconfig"
MB = 2**20
GB = 2**30
LOG = logging.getLogger(__name__)
def is_meta_device_name(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 is_network_device(name):
# return true if this is a network device
if NETWORK_NAME_RE.match(name):
return True
return False
def _get_nth_partition_for_device(device_path, partition_number):
potential_suffixes = [
str(partition_number),
"p%s" % (partition_number,),
"-part%s" % (partition_number,),
]
for suffix in potential_suffixes:
potential_partition_device = "%s%s" % (device_path, suffix)
if os.path.exists(potential_partition_device):
return potential_partition_device
return None
def _is_block_device(device_path, partition_path=None):
device_name = os.path.realpath(device_path).split("/")[-1]
sys_path = os.path.join("/sys/block/", device_name)
if partition_path is not None:
sys_path = os.path.join(
sys_path, os.path.realpath(partition_path).split("/")[-1]
)
return os.path.exists(sys_path)
def sanitize_devname(startname, transformer, log, aliases=None):
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")
if is_network_device(startname):
return startname
device_path, partition_number = util.expand_dotted_devname(devname)
orig = device_path
if aliases:
device_path = aliases.get(device_path, device_path)
if orig != device_path:
log.debug("Mapped device alias %s to %s", orig, device_path)
if is_meta_device_name(device_path):
device_path = transformer(device_path)
if not device_path:
return None
if not device_path.startswith("/"):
device_path = "/dev/%s" % (device_path,)
log.debug("Mapped metadata name %s to %s", orig, device_path)
else:
if DEVICE_NAME_RE.match(startname):
device_path = "/dev/%s" % (device_path,)
partition_path = None
if partition_number is None:
partition_path = _get_nth_partition_for_device(device_path, 1)
else:
partition_path = _get_nth_partition_for_device(
device_path, partition_number
)
if partition_path is None:
return None
if _is_block_device(device_path, partition_path):
if partition_path is not None:
return partition_path
return device_path
return None
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"]
sugg_max = memsize * 2
info = {"avail": "na", "max_in": maxsize, "mem": memsize}
if fsys is None and maxsize is None:
# set max to 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 * 0.9)):
# set to 90% of available disk space
maxsize = int(avail * 0.9)
elif maxsize is None:
maxsize = sugg_max
info["max"] = maxsize
if memsize < 4 * GB:
minsize = memsize
elif memsize < 16 * GB:
minsize = 4 * GB
else:
minsize = round(math.sqrt(memsize / GB)) * GB
size = min(minsize, maxsize)
info["size"] = size
pinfo = {}
for k, v in info.items():
if isinstance(v, int):
pinfo[k] = "%s MB" % (v / MB)
else:
pinfo[k] = v
LOG.debug(
"suggest %s swap for %s memory with '%s' disk given max=%s [max=%s]'",
pinfo["size"],
pinfo["mem"],
pinfo["avail"],
pinfo["max_in"],
pinfo["max"],
)
return size
def create_swapfile(fname: str, size: str) -> None:
"""Size is in MiB."""
errmsg = "Failed to create swapfile '%s' of size %sMB via %s: %s"
def create_swap(fname, size, method):
LOG.debug(
"Creating swapfile in '%s' on fstype '%s' using '%s'",
fname,
fstype,
method,
)
if method == "fallocate":
cmd = ["fallocate", "-l", "%sM" % size, fname]
elif method == "dd":
cmd = [
"dd",
"if=/dev/zero",
"of=%s" % fname,
"bs=1M",
"count=%s" % size,
]
try:
subp.subp(cmd, capture=True)
except subp.ProcessExecutionError as e:
LOG.info(errmsg, fname, size, method, e)
util.del_file(fname)
raise
swap_dir = os.path.dirname(fname)
util.ensure_dir(swap_dir)
fstype = util.get_mount_info(swap_dir)[1]
if (
fstype == "xfs" and util.kernel_version() < (4, 18)
) or fstype == "btrfs":
create_swap(fname, size, "dd")
else:
try:
create_swap(fname, size, "fallocate")
except subp.ProcessExecutionError:
LOG.info("fallocate swap creation failed, will attempt with dd")
create_swap(fname, size, "dd")
if os.path.exists(fname):
util.chmod(fname, 0o600)
try:
subp.subp(["mkswap", fname])
except subp.ProcessExecutionError:
util.del_file(fname)
raise
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
"""
swap_dir = os.path.dirname(fname)
if str(size).lower() == "auto":
try:
memsize = util.read_meminfo()["total"]
except IOError:
LOG.debug("Not creating swap: failed to read meminfo")
return
util.ensure_dir(swap_dir)
size = suggested_swapsize(
fsys=swap_dir, maxsize=maxsize, memsize=memsize
)
mibsize = str(int(size / (2**20)))
if not size:
LOG.debug("Not creating swap: suggested size was 0")
return
util.log_time(
LOG.debug,
msg="Setting up swap file",
func=create_swapfile,
args=[fname, mibsize],
)
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.warning("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 exists, but no /proc/swaps exists, 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 exists, but not in /proc/swaps", fname)
except Exception:
LOG.warning(
"swap file %s exists. 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.warning("failed to setup swap: %s", e)
return None
def handle(
name: str, cfg: Config, cloud: Cloud, log: Logger, args: list
) -> None:
# fs_spec, fs_file, fs_vfstype, fs_mntops, fs-freq, fs_passno
def_mnt_opts = "defaults,nobootwait"
uses_systemd = cloud.distro.uses_systemd()
if uses_systemd:
def_mnt_opts = (
"defaults,nofail,x-systemd.requires=cloud-init.service,_netdev"
)
defvals = [None, None, "auto", def_mnt_opts, "0", "2"]
defvals = cfg.get("mount_default_fields", defvals)
# these are our default set of mounts
defmnts: list = [
["ephemeral0", "/mnt", "auto", defvals[3], "0", "2"],
["swap", "none", "swap", "sw", "0", "0"],
]
cfgmnt = []
if "mounts" in cfg:
cfgmnt = cfg["mounts"]
LOG.debug("mounts configuration is %s", cfgmnt)
fstab_lines = []
fstab_devs = {}
fstab_removed = []
if os.path.exists(FSTAB_PATH):
for line in util.load_file(FSTAB_PATH).splitlines():
if MNT_COMMENT in line:
fstab_removed.append(line)
continue
try:
toks = WS.split(line)
except Exception:
pass
fstab_devs[toks[0]] = line
fstab_lines.append(line)
device_aliases = cfg.get("device_aliases", {})
for i in range(len(cfgmnt)):
# skip something that wasn't a list
if not isinstance(cfgmnt[i], list):
log.warning(
"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, aliases=device_aliases
)
if sanitized != start:
log.debug("changed %s => %s" % (start, sanitized))
if sanitized is None:
log.debug("Ignoring nonexistent named mount %s", start)
continue
elif sanitized in fstab_devs:
log.info(
"Device %s already defined in fstab: %s",
sanitized,
fstab_devs[sanitized],
)
continue
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, aliases=device_aliases
)
if sanitized != start:
log.debug("changed default device %s => %s" % (start, sanitized))
if sanitized is None:
log.debug("Ignoring nonexistent default named mount %s", start)
continue
elif sanitized in fstab_devs:
log.debug(
"Device %s already defined in fstab: %s",
sanitized,
fstab_devs[sanitized],
)
continue
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 nonexistent 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
cc_lines = []
needswap = False
need_mount_all = False
dirs = []
for line in actlist:
# write 'comment' in the fs_mntops, entry, claiming this
line[3] = "%s,%s" % (line[3], MNT_COMMENT)
if line[2] == "swap":
needswap = True
if line[1].startswith("/"):
dirs.append(line[1])
cc_lines.append("\t".join(line))
mount_points = [
v["mountpoint"] for k, v in util.mounts().items() if "mountpoint" in v
]
for d in dirs:
try:
util.ensure_dir(d)
except Exception:
util.logexc(log, "Failed to make '%s' config-mount", d)
# dirs is list of directories on which a volume should be mounted.
# If any of them does not already show up in the list of current
# mount points, we will definitely need to do mount -a.
if not need_mount_all and d not in mount_points:
need_mount_all = True
sadds = [WS.sub(" ", n) for n in cc_lines]
sdrops = [WS.sub(" ", n) for n in fstab_removed]
sops = ["- " + drop for drop in sdrops if drop not in sadds] + [
"+ " + add for add in sadds if add not in sdrops
]
fstab_lines.extend(cc_lines)
contents = "%s\n" % "\n".join(fstab_lines)
util.write_file(FSTAB_PATH, contents)
activate_cmds = []
if needswap:
activate_cmds.append(["swapon", "-a"])
if len(sops) == 0:
log.debug("No changes to /etc/fstab made.")
else:
log.debug("Changes to fstab: %s", sops)
need_mount_all = True
if need_mount_all:
activate_cmds.append(["mount", "-a"])
if uses_systemd:
activate_cmds.append(["systemctl", "daemon-reload"])
fmt = "Activating swap and mounts with: %s"
for cmd in activate_cmds:
fmt = "Activate mounts: %s:" + " ".join(cmd)
try:
subp.subp(cmd)
log.debug(fmt, "PASS")
except subp.ProcessExecutionError:
log.warning(fmt, "FAIL")
util.logexc(log, fmt, "FAIL")
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