Current File : //snap/core20/2318/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 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 values to be specified
for the fields in a ``mounts`` entry that are not specified, aside from the
``fs_spec`` and the ``fs_file`` fields. 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.
.. note::
If multiple mounts are specified where a subsequent mount's mountpoint is
inside of a previously declared mount's mountpoint (i.e. the 1st mount has
a mountpoint of ``/abc`` and the 2nd mount has a mountpoint of
``/abc/def``) then this will not work as expected - ``cc_mounts`` first
creates the directories for all the mountpoints **before** it starts to
perform any mounts and so the sub-mountpoint directory will not be created
correctly inside the parent mountpoint.
For systems using util-linux's ``mount`` program this issue can be
worked around by specifying ``X-mount.mkdir`` as part of a ``fs_mntops``
value for the subsequent mount entry.
"""
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, 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 == "btrfs":
subp.subp(["truncate", "-s", "0", fname])
subp.subp(["chattr", "+C", fname])
if fstype == "xfs" and util.kernel_version() < (4, 18):
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, 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, 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, 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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