# 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 file is part of cloud-init. See LICENSE file for license information.
"""Growpart: Grow partitions"""
import base64
import copy
import json
import logging
import os
import os.path
import re
import stat
from abc import ABC, abstractmethod
from contextlib import suppress
from pathlib import Path
from typing import Optional, Tuple
from cloudinit import lifecycle, performance, subp, temp_utils, util
from cloudinit.cloud import Cloud
from cloudinit.config import Config
from cloudinit.config.schema import MetaSchema
from cloudinit.distros import ALL_DISTROS, Distro
from cloudinit.settings import PER_ALWAYS
frequency = PER_ALWAYS
meta: MetaSchema = {
"id": "cc_growpart",
"distros": [ALL_DISTROS],
"frequency": frequency,
"activate_by_schema_keys": [],
}
DEFAULT_CONFIG = {
"mode": "auto",
"devices": ["/"],
"ignore_growroot_disabled": False,
}
KEYDATA_PATH = Path("/cc_growpart_keydata")
class RESIZE:
SKIPPED = "SKIPPED"
CHANGED = "CHANGED"
NOCHANGE = "NOCHANGE"
FAILED = "FAILED"
LOG = logging.getLogger(__name__)
class ResizeFailedException(Exception):
pass
class Resizer(ABC):
def __init__(self, distro: Distro):
self._distro = distro
@abstractmethod
def available(self, devices: list) -> bool: ...
@abstractmethod
def resize(self, diskdev, partnum, partdev, fs): ...
class ResizeGrowPart(Resizer):
def available(self, devices: list):
try:
out = subp.subp(
["growpart", "--help"], update_env={"LANG": "C"}
).stdout
if re.search(r"--update\s+", out):
return True
except subp.ProcessExecutionError:
pass
return False
def resize(self, diskdev, partnum, partdev, fs):
before = get_size(partdev, fs)
# growpart uses tmp dir to store intermediate states
# and may conflict with systemd-tmpfiles-clean
tmp_dir = self._distro.get_tmp_exec_path()
with temp_utils.tempdir(dir=tmp_dir, needs_exe=True) as tmpd:
growpart_tmp = os.path.join(tmpd, "growpart")
my_env = {"LANG": "C", "TMPDIR": growpart_tmp}
if not os.path.exists(growpart_tmp):
os.mkdir(growpart_tmp, 0o700)
try:
subp.subp(
["growpart", "--dry-run", diskdev, partnum],
update_env=my_env,
)
except subp.ProcessExecutionError as e:
if e.exit_code != 1:
util.logexc(
LOG,
"Failed growpart --dry-run for (%s, %s)",
diskdev,
partnum,
)
raise ResizeFailedException(e) from e
return (before, before)
try:
subp.subp(["growpart", diskdev, partnum], update_env=my_env)
except subp.ProcessExecutionError as e:
util.logexc(LOG, "Failed: growpart %s %s", diskdev, partnum)
raise ResizeFailedException(e) from e
return (before, get_size(partdev, fs))
class ResizeGrowFS(Resizer):
"""
Use FreeBSD ``growfs`` service to grow root partition to fill available
space, optionally adding a swap partition at the end.
Note that the service file warns us that it uses ``awk(1)``, and as
such requires ``/usr`` to be present. However, cloud-init is installed
into ``/usr/local``, so we should be fine.
We invoke the ``growfs`` with ``service growfs onestart``, so it
doesn't need to be enabled in ``rc.conf``.
"""
def available(self, devices: list):
"""growfs only works on the root partition"""
return os.path.isfile("/etc/rc.d/growfs") and devices == ["/"]
def resize(self, diskdev, partnum, partdev, fs):
before = get_size(partdev, fs)
try:
self._distro.manage_service(action="onestart", service="growfs")
except subp.ProcessExecutionError as e:
util.logexc(LOG, "Failed: service growfs onestart")
raise ResizeFailedException(e) from e
return (before, get_size(partdev, fs))
class ResizeGpart(Resizer):
def available(self, devices: list):
try:
err = subp.subp(
["gpart", "help"], update_env={"LANG": "C"}, rcs=[0, 1]
).stderr
if re.search(r"gpart recover ", err):
return True
except subp.ProcessExecutionError:
pass
return False
def resize(self, diskdev, partnum, partdev, fs):
"""
GPT disks store metadata at the beginning (primary) and at the
end (secondary) of the disk. When launching an image with a
larger disk compared to the original image, the secondary copy
is lost. Thus, the metadata will be marked CORRUPT, and need to
be recovered.
"""
try:
subp.subp(["gpart", "recover", diskdev])
except subp.ProcessExecutionError as e:
if e.exit_code != 0:
util.logexc(LOG, "Failed: gpart recover %s", diskdev)
raise ResizeFailedException(e) from e
before = get_size(partdev, fs)
try:
subp.subp(["gpart", "resize", "-i", partnum, diskdev])
except subp.ProcessExecutionError as e:
util.logexc(LOG, "Failed: gpart resize -i %s %s", partnum, diskdev)
raise ResizeFailedException(e) from e
return (before, get_size(partdev, fs))
def resizer_factory(mode: str, distro: Distro, devices: list) -> Resizer:
resize_class = None
if mode == "auto":
for _name, resizer in RESIZERS:
cur = resizer(distro)
if cur.available(devices=devices):
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](distro)
if mclass.available(devices=devices):
resize_class = mclass
if not resize_class:
raise ValueError("mode %s not available" % mode)
return resize_class
def get_size(filename, fs) -> Optional[int]:
fd = None
try:
fd = os.open(filename, os.O_RDONLY)
return os.lseek(fd, 0, os.SEEK_END)
except FileNotFoundError:
if fs == "zfs":
return get_zfs_size(filename)
return None
finally:
if fd:
os.close(fd)
def get_zfs_size(dataset) -> Optional[int]:
zpool = dataset.split("/")[0]
try:
size, _ = subp.subp(["zpool", "get", "-Hpovalue", "size", zpool])
except subp.ProcessExecutionError as e:
LOG.debug("Failed: zpool get size %s: %s", zpool, e)
return None
return int(size.strip())
def devent2dev(devent):
if devent.startswith("/dev/"):
return devent, None
result = util.get_mount_info(devent)
if not result:
raise ValueError("Could not determine device of '%s' % dev_ent")
dev = result[0]
fs = result[1]
container = util.is_container()
# Ensure the path is a block device.
if dev == "/dev/root" and not container:
dev = util.rootdev_from_cmdline(util.get_cmdline())
if dev is None:
if os.path.exists(dev):
# if /dev/root exists, but we failed to convert
# that to a "real" /dev/ path device, then return it.
return dev, None
raise ValueError("Unable to find device '/dev/root'")
return dev, fs
def is_encrypted(blockdev, partition) -> bool:
"""
Check if a device is an encrypted device. blockdev should have
a /dev/dm-* path whereas partition is something like /dev/sda1.
"""
if not subp.which("cryptsetup"):
LOG.debug("cryptsetup not found. Assuming no encrypted partitions")
return False
try:
subp.subp(["cryptsetup", "status", blockdev])
except subp.ProcessExecutionError as e:
if e.exit_code == 4:
LOG.debug("Determined that %s is not encrypted", blockdev)
else:
LOG.warning(
"Received unexpected exit code %s from "
"cryptsetup status. Assuming no encrypted partitions.",
e.exit_code,
)
return False
with suppress(subp.ProcessExecutionError):
subp.subp(["cryptsetup", "isLuks", partition])
LOG.debug("Determined that %s is encrypted", blockdev)
return True
return False
def get_underlying_partition(blockdev):
command = ["dmsetup", "deps", "--options=devname", blockdev]
dep: str = subp.subp(command)[0] # pyright: ignore
# Returned result should look something like:
# 1 dependencies : (vdb1)
if not dep.startswith("1 depend"):
raise RuntimeError(
f"Expecting '1 dependencies' from 'dmsetup'. Received: {dep}"
)
try:
return f'/dev/{dep.split(": (")[1].split(")")[0]}'
except IndexError as e:
raise RuntimeError(
f"Ran `{command}`, but received unexpected stdout: `{dep}`"
) from e
def resize_encrypted(blockdev, partition) -> Tuple[str, str]:
"""Use 'cryptsetup resize' to resize LUKS volume.
The loaded keyfile is json formatted with 'key' and 'slot' keys.
key is base64 encoded. Example:
{"key":"XFmCwX2FHIQp0LBWaLEMiHIyfxt1SGm16VvUAVledlY=","slot":5}
"""
if not KEYDATA_PATH.exists():
return (RESIZE.SKIPPED, "No encryption keyfile found")
try:
with performance.Timed(
f"Reading {KEYDATA_PATH}"
), KEYDATA_PATH.open() as f:
keydata = json.load(f)
key = keydata["key"]
decoded_key = base64.b64decode(key)
slot = keydata["slot"]
except Exception as e:
raise RuntimeError(
"Could not load encryption key. This is expected if "
"the volume has been previously resized."
) from e
try:
subp.subp(
["cryptsetup", "--key-file", "-", "resize", blockdev],
data=decoded_key,
)
finally:
try:
subp.subp(
[
"cryptsetup",
"luksKillSlot",
"--batch-mode",
partition,
str(slot),
]
)
except subp.ProcessExecutionError as e:
LOG.warning(
"Failed to kill luks slot after resizing encrypted volume: %s",
e,
)
try:
KEYDATA_PATH.unlink()
except Exception:
util.logexc(
LOG, "Failed to remove keyfile after resizing encrypted volume"
)
return (
RESIZE.CHANGED,
f"Successfully resized encrypted volume '{blockdev}'",
)
def _call_resizer(resizer, devent, disk, ptnum, blockdev, fs):
info = []
try:
old, new = resizer.resize(disk, ptnum, blockdev, fs)
if old == new:
info.append(
(
devent,
RESIZE.NOCHANGE,
"no change necessary (%s, %s)" % (disk, ptnum),
)
)
elif new is None or old is None:
msg = ""
if disk is not None and ptnum is None:
msg = "changed (%s, %s) size, new size is unknown" % (
disk,
ptnum,
)
else:
msg = "changed (%s) size, new size is unknown" % blockdev
info.append((devent, RESIZE.CHANGED, msg))
else:
msg = ""
if disk is not None and ptnum is None:
msg = "changed (%s, %s) from %s to %s" % (
disk,
ptnum,
old,
new,
)
else:
msg = "changed (%s) from %s to %s" % (blockdev, old, new)
info.append((devent, RESIZE.CHANGED, msg))
except ResizeFailedException as e:
info.append(
(
devent,
RESIZE.FAILED,
"failed to resize: disk=%s, ptnum=%s: %s" % (disk, ptnum, e),
)
)
return info
def resize_devices(resizer: Resizer, devices, distro: Distro):
# returns a tuple of tuples containing (entry-in-devices, action, message)
devices = copy.copy(devices)
info = []
while devices:
devent = devices.pop(0)
disk = None
ptnum = None
try:
blockdev, fs = devent2dev(devent)
except ValueError as e:
info.append(
(
devent,
RESIZE.SKIPPED,
"unable to convert to device: %s" % e,
)
)
continue
LOG.debug("growpart found fs=%s", fs)
# TODO: This seems to be the wrong place for this. On Linux, we the
# `os.stat(blockdev)` call below will fail on a ZFS filesystem.
# We then delay resizing the FS until calling cc_resizefs. Yet
# the code here is to accommodate the FreeBSD `growfs` service.
# Ideally we would grow the FS for both OSes in the same module.
if fs == "zfs" and isinstance(resizer, ResizeGrowFS):
info += _call_resizer(resizer, devent, disk, ptnum, blockdev, fs)
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) and not stat.S_ISCHR(
statret.st_mode
):
info.append(
(
devent,
RESIZE.SKIPPED,
"device '%s' not a block device" % blockdev,
)
)
continue
underlying_blockdev = distro.get_mapped_device(blockdev)
if underlying_blockdev:
try:
# We need to resize the underlying partition first
partition = get_underlying_partition(blockdev)
if is_encrypted(underlying_blockdev, partition):
if partition not in [x[0] for x in info]:
# We shouldn't attempt to resize this mapped partition
# until the underlying partition is resized, so re-add
# our device to the beginning of the list we're
# iterating over, then add our underlying partition
# so it can get processed first
devices.insert(0, devent)
devices.insert(0, partition)
continue
status, message = resize_encrypted(blockdev, partition)
info.append(
(
devent,
status,
message,
)
)
else:
info.append(
(
devent,
RESIZE.SKIPPED,
f"Resizing mapped device ({blockdev}) skipped "
"as it is not encrypted.",
)
)
except Exception as e:
info.append(
(
devent,
RESIZE.FAILED,
f"Resizing encrypted device ({blockdev}) failed: {e}",
)
)
# At this point, we WON'T resize a non-encrypted mapped device
# though we should probably grow the ability to
continue
try:
disk, ptnum = distro.device_part_info(blockdev)
except (TypeError, ValueError) as e:
info.append(
(
devent,
RESIZE.SKIPPED,
"device_part_info(%s) failed: %s" % (blockdev, e),
)
)
continue
info += _call_resizer(resizer, devent, disk, ptnum, blockdev, fs)
return info
def handle(name: str, cfg: Config, cloud: Cloud, args: list) -> None:
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.warning("'growpart' in config was not a dict")
return
mode = mycfg.get("mode", "auto")
if util.is_false(mode):
if mode != "off":
lifecycle.deprecate(
deprecated=f"Growpart's 'mode' key with value '{mode}'",
deprecated_version="22.2",
extra_message="Use 'off' instead.",
)
LOG.debug("growpart disabled: mode=%s", mode)
return
if util.is_false(mycfg.get("ignore_growroot_disabled", False)):
if os.path.isfile("/etc/growroot-disabled"):
LOG.debug("growpart disabled: /etc/growroot-disabled exists")
LOG.debug("use ignore_growroot_disabled to ignore")
return
devices = util.get_cfg_option_list(mycfg, "devices", ["/"])
if not len(devices):
LOG.debug("growpart: empty device list")
return
try:
resizer = resizer_factory(mode, distro=cloud.distro, devices=devices)
except (ValueError, TypeError) as e:
LOG.debug("growpart unable to find resizer for '%s': %s", mode, e)
if mode != "auto":
raise e
return
with performance.Timed("Resizing devices"):
resized = resize_devices(resizer, devices, cloud.distro)
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 = (
("growpart", ResizeGrowPart),
("growfs", ResizeGrowFS),
("gpart", ResizeGpart),
)