# Copyright (C) 2011 Canonical Ltd. # Copyright (C) 2013 Hewlett-Packard Development Company, L.P. # # Author: Scott Moser # Author: Juerg Haefliger # # This file is part of cloud-init. See LICENSE file for license information. """ Growpart -------- **Summary:** grow partitions Growpart resizes partitions to fill the available disk space. This is useful for cloud instances with a larger amount of disk space available than the pristine image uses, as it allows the instance to automatically make use of the extra space. The devices run growpart on are specified as a list under the ``devices`` key. Each entry in the devices list can be either the path to the device's mountpoint in the filesystem or a path to the block device in ``/dev``. The utility to use for resizing can be selected using the ``mode`` config key. If ``mode`` key is set to ``auto``, then any available utility (either ``growpart`` or BSD ``gpart``) will be used. If neither utility is available, no error will be raised. If ``mode`` is set to ``growpart``, then the ``growpart`` utility will be used. If this utility is not available on the system, this will result in an error. If ``mode`` is set to ``off`` or ``false``, then ``cc_growpart`` will take no action. There is some functionality overlap between this module and the ``growroot`` functionality of ``cloud-initramfs-tools``. However, there are some situations where one tool is able to function and the other is not. The default configuration for both should work for most cloud instances. To explicitly prevent ``cloud-initramfs-tools`` from running ``growroot``, the file ``/etc/growroot-disabled`` can be created. By default, both ``growroot`` and ``cc_growpart`` will check for the existance of this file and will not run if it is present. However, this file can be ignored for ``cc_growpart`` by setting ``ignore_growroot_disabled`` to ``true``. For more information on ``cloud-initramfs-tools`` see: https://launchpad.net/cloud-initramfs-tools Growpart is enabled by default on the root partition. The default config for growpart is:: growpart: mode: auto devices: ["/"] ignore_growroot_disabled: false **Internal name:** ``cc_growpart`` **Module frequency:** per always **Supported distros:** all **Config keys**:: growpart: mode: devices: - "/" - "/dev/vdb1" ignore_growroot_disabled: """ import os import os.path import re import stat from cloudinit import log as logging from cloudinit.settings import PER_ALWAYS from cloudinit import subp from cloudinit import util frequency = PER_ALWAYS DEFAULT_CONFIG = { 'mode': 'auto', 'devices': ['/'], 'ignore_growroot_disabled': False, } class RESIZE(object): 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 ResizeGrowPart(object): def available(self): myenv = os.environ.copy() myenv['LANG'] = 'C' try: (out, _err) = subp.subp(["growpart", "--help"], env=myenv) if re.search(r"--update\s+", out): return True except subp.ProcessExecutionError: pass return False def resize(self, diskdev, partnum, partdev): before = get_size(partdev) try: subp.subp(["growpart", '--dry-run', diskdev, partnum]) 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]) except subp.ProcessExecutionError as e: util.logexc(LOG, "Failed: growpart %s %s", diskdev, partnum) raise ResizeFailedException(e) from e return (before, get_size(partdev)) class ResizeGpart(object): def available(self): myenv = os.environ.copy() myenv['LANG'] = 'C' try: (_out, err) = subp.subp(["gpart", "help"], env=myenv, rcs=[0, 1]) if re.search(r"gpart recover ", err): return True except subp.ProcessExecutionError: pass return False def resize(self, diskdev, partnum, partdev): """ 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) 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)) 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 # FreeBSD doesn't know of sysfs so just get everything we need from # the device, like /dev/vtbd0p2. if util.is_FreeBSD(): freebsd_part = "/dev/" + util.find_freebsd_part(devpath) m = re.search('^(/dev/.+)p([0-9])$', freebsd_part) return (m.group(1), m.group(2)) 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") dev = result[0] 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 raise ValueError("Unable to find device '/dev/root'") return dev 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) and not stat.S_ISCHR(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.warning("'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 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) 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 = (('growpart', ResizeGrowPart), ('gpart', ResizeGpart)) # vi: ts=4 expandtab