name : cc_disk_setup.py # Copyright (C) 2009-2010 Canonical Ltd. # Copyright (C) 2012 Hewlett-Packard Development Company, L.P. # # Author: Ben Howard <ben.howard@canonical.com> # # This file is part of cloud-init. See LICENSE file for license information. """Disk Setup: Configure partitions and filesystems.""" import logging import os import shlex from textwrap import dedent from cloudinit import subp, util from cloudinit.cloud import Cloud from cloudinit.config import Config from cloudinit.config.schema import MetaSchema, get_meta_doc from cloudinit.distros import ALL_DISTROS from cloudinit.settings import PER_INSTANCE # Define the commands to use SFDISK_CMD = subp.which("sfdisk") SGDISK_CMD = subp.which("sgdisk") LSBLK_CMD = subp.which("lsblk") BLKID_CMD = subp.which("blkid") BLKDEV_CMD = subp.which("blockdev") PARTPROBE_CMD = subp.which("partprobe") WIPEFS_CMD = subp.which("wipefs") LANG_C_ENV = {"LANG": "C"} LOG = logging.getLogger(__name__) MODULE_DESCRIPTION = """\ This module is able to configure simple partition tables and filesystems. .. note:: for more detail about configuration options for disk setup, see the disk setup example .. note:: if a swap partition is being created via ``disk_setup`` then a ``fs_entry`` entry is also needed in order for mkswap to be run, otherwise when swap activation is later attempted it will fail. For convenience, aliases can be specified for disks using the ``device_aliases`` config key, which takes a dictionary of alias: path mappings. There are automatic aliases for ``swap`` and ``ephemeral<X>``, where ``swap`` will always refer to the active swap partition and ``ephemeral<X>`` will refer to the block device of the ephemeral image. Disk partitioning is done using the ``disk_setup`` directive. This config directive accepts a dictionary where each key is either a path to a block device or an alias specified in ``device_aliases``, and each value is the configuration options for the device. File system configuration is done using the ``fs_setup`` directive. This config directive accepts a list of filesystem configs. """ meta: MetaSchema = { "id": "cc_disk_setup", "name": "Disk Setup", "title": "Configure partitions and filesystems", "description": MODULE_DESCRIPTION, "distros": [ALL_DISTROS], "frequency": PER_INSTANCE, "examples": [ dedent( """\ device_aliases: my_alias: /dev/sdb swap_disk: /dev/sdc disk_setup: my_alias: table_type: gpt layout: [50, 50] overwrite: true swap_disk: table_type: gpt layout: [[100, 82]] overwrite: true /dev/sdd: table_type: mbr layout: true overwrite: true fs_setup: - label: fs1 filesystem: ext4 device: my_alias.1 cmd: mkfs -t %(filesystem)s -L %(label)s %(device)s - label: fs2 device: my_alias.2 filesystem: ext4 - label: swap device: swap_disk.1 filesystem: swap - label: fs3 device: /dev/sdd1 filesystem: ext4 mounts: - ["my_alias.1", "/mnt1"] - ["my_alias.2", "/mnt2"] - ["swap_disk.1", "none", "swap", "sw", "0", "0"] - ["/dev/sdd1", "/mnt3"] """ ) ], "activate_by_schema_keys": ["disk_setup", "fs_setup"], } __doc__ = get_meta_doc(meta) def handle(name: str, cfg: Config, cloud: Cloud, args: list) -> None: """ See doc/examples/cloud-config-disk-setup.txt for documentation on the format. """ device_aliases = cfg.get("device_aliases", {}) def alias_to_device(cand): name = device_aliases.get(cand) return cloud.device_name_to_device(name or cand) or name disk_setup = cfg.get("disk_setup") if isinstance(disk_setup, dict): update_disk_setup_devices(disk_setup, alias_to_device) LOG.debug("Partitioning disks: %s", str(disk_setup)) for disk, definition in disk_setup.items(): if not isinstance(definition, dict): LOG.warning("Invalid disk definition for %s", disk) continue try: LOG.debug("Creating new partition table/disk") util.log_time( logfunc=LOG.debug, msg="Creating partition on %s" % disk, func=mkpart, args=(disk, definition), ) except Exception as e: util.logexc(LOG, "Failed partitioning operation\n%s" % e) fs_setup = cfg.get("fs_setup") if isinstance(fs_setup, list): LOG.debug("setting up filesystems: %s", str(fs_setup)) update_fs_setup_devices(fs_setup, alias_to_device) for definition in fs_setup: if not isinstance(definition, dict): LOG.warning("Invalid file system definition: %s", definition) continue try: LOG.debug("Creating new filesystem.") device = definition.get("device") util.log_time( logfunc=LOG.debug, msg="Creating fs for %s" % device, func=mkfs, args=(definition,), ) except Exception as e: util.logexc(LOG, "Failed during filesystem operation\n%s" % e) def update_disk_setup_devices(disk_setup, tformer): # update 'disk_setup' dictionary anywhere were a device may occur # update it with the response from 'tformer' for origname in list(disk_setup): transformed = tformer(origname) if transformed is None or transformed == origname: continue if transformed in disk_setup: LOG.info( "Replacing %s in disk_setup for translation of %s", origname, transformed, ) del disk_setup[transformed] disk_setup[transformed] = disk_setup[origname] if isinstance(disk_setup[transformed], dict): disk_setup[transformed]["_origname"] = origname del disk_setup[origname] LOG.debug( "updated disk_setup device entry '%s' to '%s'", origname, transformed, ) def update_fs_setup_devices(disk_setup, tformer): # update 'fs_setup' dictionary anywhere were a device may occur # update it with the response from 'tformer' for definition in disk_setup: if not isinstance(definition, dict): LOG.warning("entry in disk_setup not a dict: %s", definition) continue origname = definition.get("device") if origname is None: continue (dev, part) = util.expand_dotted_devname(origname) tformed = tformer(dev) if tformed is not None: dev = tformed LOG.debug( "%s is mapped to disk=%s part=%s", origname, tformed, part ) definition["_origname"] = origname definition["device"] = tformed if part: # In origname with <dev>.N, N overrides 'partition' key. if "partition" in definition: LOG.warning( "Partition '%s' from dotted device name '%s' " "overrides 'partition' key in %s", part, origname, definition, ) definition["_partition"] = definition["partition"] definition["partition"] = part def value_splitter(values, start=None): """ Returns the key/value pairs of output sent as string like: FOO='BAR' HOME='127.0.0.1' """ _values = shlex.split(values) if start: _values = _values[start:] for key, value in [x.split("=") for x in _values]: yield key, value def enumerate_disk(device, nodeps=False): """ Enumerate the elements of a child device. Parameters: device: the kernel device name nodeps <BOOL>: don't enumerate children devices Return a dict describing the disk: type: the entry type, i.e disk or part fstype: the filesystem type, if it exists label: file system label, if it exists name: the device name, i.e. sda """ lsblk_cmd = [ LSBLK_CMD, "--pairs", "--output", "NAME,TYPE,FSTYPE,LABEL", device, ] if nodeps: lsblk_cmd.append("--nodeps") info = None try: info, _err = subp.subp(lsblk_cmd) except Exception as e: raise RuntimeError( "Failed during disk check for %s\n%s" % (device, e) ) from e parts = [x for x in (info.strip()).splitlines() if len(x.split()) > 0] for part in parts: d = { "name": None, "type": None, "fstype": None, "label": None, } for key, value in value_splitter(part): d[key.lower()] = value yield d def device_type(device): """ Return the device type of the device by calling lsblk. """ for d in enumerate_disk(device, nodeps=True): if "type" in d: return d["type"].lower() return None def is_device_valid(name, partition=False): """ Check if the device is a valid device. """ d_type = "" try: d_type = device_type(name) except Exception: LOG.warning("Query against device %s failed", name) return False if partition and d_type == "part": return True elif not partition and d_type == "disk": return True return False def check_fs(device): """ Check if the device has a filesystem on it Output of blkid is generally something like: /dev/sda: LABEL="Backup500G" UUID="..." TYPE="ext4" Return values are device, label, type, uuid """ out, label, fs_type, uuid = None, None, None, None blkid_cmd = [BLKID_CMD, "-c", "/dev/null", device] try: out, _err = subp.subp(blkid_cmd, rcs=[0, 2]) except Exception as e: raise RuntimeError( "Failed during disk check for %s\n%s" % (device, e) ) from e if out: if len(out.splitlines()) == 1: for key, value in value_splitter(out, start=1): if key.lower() == "label": label = value elif key.lower() == "type": fs_type = value elif key.lower() == "uuid": uuid = value return label, fs_type, uuid def is_filesystem(device): """ Returns true if the device has a file system. """ _, fs_type, _ = check_fs(device) return fs_type def find_device_node( device, fs_type=None, label=None, valid_targets=None, label_match=True, replace_fs=None, ): """ Find a device that is either matches the spec, or the first The return is value is (<device>, <bool>) where the device is the device to use and the bool is whether the device matches the fs_type and label. Note: This works with GPT partition tables! """ # label of None is same as no label if label is None: label = "" if not valid_targets: valid_targets = ["disk", "part"] raw_device_used = False for d in enumerate_disk(device): if d["fstype"] == replace_fs and label_match is False: # We found a device where we want to replace the FS return ("/dev/%s" % d["name"], False) if d["fstype"] == fs_type and ( (label_match and d["label"] == label) or not label_match ): # If we find a matching device, we return that return ("/dev/%s" % d["name"], True) if d["type"] in valid_targets: if d["type"] != "disk" or d["fstype"]: raw_device_used = True if d["type"] == "disk": # Skip the raw disk, its the default pass elif not d["fstype"]: return ("/dev/%s" % d["name"], False) if not raw_device_used: return (device, False) LOG.warning("Failed to find device during available device search.") return (None, False) def is_disk_used(device): """ Check if the device is currently used. Returns true if the device has either a file system or a partition entry is no filesystem found on the disk. """ # If the child count is higher 1, then there are child nodes # such as partition or device mapper nodes if len(list(enumerate_disk(device))) > 1: return True # If we see a file system, then its used _, check_fstype, _ = check_fs(device) if check_fstype: return True return False def get_hdd_size(device): try: size_in_bytes, _ = subp.subp([BLKDEV_CMD, "--getsize64", device]) sector_size, _ = subp.subp([BLKDEV_CMD, "--getss", device]) except Exception as e: raise RuntimeError("Failed to get %s size\n%s" % (device, e)) from e return int(size_in_bytes) / int(sector_size) def check_partition_mbr_layout(device, layout): """ Returns true if the partition layout matches the one on the disk Layout should be a list of values. At this time, this only verifies that the number of partitions and their labels is correct. """ read_parttbl(device) prt_cmd = [SFDISK_CMD, "-l", device] try: out, _err = subp.subp(prt_cmd, data="%s\n" % layout) except Exception as e: raise RuntimeError( "Error running partition command on %s\n%s" % (device, e) ) from e found_layout = [] for line in out.splitlines(): _line = line.split() if len(_line) == 0: continue if device in _line[0]: # We don't understand extended partitions yet if _line[-1].lower() in ["extended", "empty"]: continue # Find the partition types type_label = None for x in sorted(range(1, len(_line)), reverse=True): if _line[x].isdigit() and _line[x] != "/": type_label = _line[x] break found_layout.append(type_label) return found_layout def check_partition_gpt_layout(device, layout): prt_cmd = [SGDISK_CMD, "-p", device] try: out, _err = subp.subp(prt_cmd, update_env=LANG_C_ENV) except Exception as e: raise RuntimeError( "Error running partition command on %s\n%s" % (device, e) ) from e out_lines = iter(out.splitlines()) # Skip header. Output looks like: # *************************************************************** # Found invalid GPT and valid MBR; converting MBR to GPT format # in memory. # *************************************************************** # # Disk /dev/vdb: 83886080 sectors, 40.0 GiB # Logical sector size: 512 bytes # Disk identifier (GUID): 8A7F11AD-3953-491B-8051-077E01C8E9A7 # Partition table holds up to 128 entries # First usable sector is 34, last usable sector is 83886046 # Partitions will be aligned on 2048-sector boundaries # Total free space is 83476413 sectors (39.8 GiB) # # Number Start (sector) End (sector) Size Code Name # 1 2048 206847 100.0 MiB 0700 Microsoft basic data for line in out_lines: if line.strip().startswith("Number"): break codes = [line.strip().split()[5] for line in out_lines] cleaned = [] # user would expect a code '83' to be Linux, but sgdisk outputs 8300. for code in codes: if len(code) == 4 and code.endswith("00"): code = code[0:2] cleaned.append(code) return cleaned def check_partition_layout(table_type, device, layout): """ See if the partition lay out matches. This is future a future proofing function. In order to add support for other disk layout schemes, add a function called check_partition_%s_layout """ if "gpt" == table_type: found_layout = check_partition_gpt_layout(device, layout) elif "mbr" == table_type: found_layout = check_partition_mbr_layout(device, layout) else: raise RuntimeError("Unable to determine table type") LOG.debug( "called check_partition_%s_layout(%s, %s), returned: %s", table_type, device, layout, found_layout, ) if isinstance(layout, bool): # if we are using auto partitioning, or "True" be happy # if a single partition exists. if layout and len(found_layout) >= 1: return True return False elif len(found_layout) == len(layout): # This just makes sure that the number of requested # partitions and the type labels are right layout_types = [ str(x[1]) if isinstance(x, (tuple, list)) else None for x in layout ] LOG.debug( "Layout types=%s. Found types=%s", layout_types, found_layout ) for itype, ftype in zip(layout_types, found_layout): if itype is not None and str(ftype) != str(itype): return False return True return False def get_partition_mbr_layout(size, layout): """ Calculate the layout of the partition table. Partition sizes are defined as percentage values or a tuple of percentage and partition type. For example: [ 33, [66: 82] ] Defines the first partition to be a size of 1/3 the disk, while the remaining 2/3's will be of type Linux Swap. """ if not isinstance(layout, list) and isinstance(layout, bool): # Create a single partition, default to Linux return ",,83" if (len(layout) == 0 and isinstance(layout, list)) or not isinstance( layout, list ): raise RuntimeError("Partition layout is invalid") last_part_num = len(layout) if last_part_num > 4: raise RuntimeError("Only simply partitioning is allowed.") part_definition = [] part_num = 0 for part in layout: part_type = 83 # Default to Linux percent = part part_num += 1 if isinstance(part, list): if len(part) != 2: raise RuntimeError( "Partition was incorrectly defined: %s" % part ) percent, part_type = part part_size = int(float(size) * (float(percent) / 100)) if part_num == last_part_num: part_definition.append(",,%s" % part_type) else: part_definition.append(",%s,%s" % (part_size, part_type)) sfdisk_definition = "\n".join(part_definition) if len(part_definition) > 4: raise RuntimeError( "Calculated partition definition is too big\n%s" % sfdisk_definition ) return sfdisk_definition def get_partition_gpt_layout(size, layout): if isinstance(layout, bool): return [(None, [0, 0])] partition_specs = [] for partition in layout: if isinstance(partition, list): if len(partition) != 2: raise RuntimeError( "Partition was incorrectly defined: %s" % partition ) percent, partition_type = partition else: percent = partition partition_type = None part_size = int(float(size) * (float(percent) / 100)) partition_specs.append((partition_type, [0, "+{}".format(part_size)])) # The last partition should use up all remaining space partition_specs[-1][-1][-1] = 0 return partition_specs def purge_disk_ptable(device): # wipe the first and last megabyte of a disk (or file) # gpt stores partition table both at front and at end. null = b"\0" start_len = 1024 * 1024 end_len = 1024 * 1024 with open(device, "rb+") as fp: fp.write(null * (start_len)) fp.seek(-end_len, os.SEEK_END) fp.write(null * end_len) fp.flush() read_parttbl(device) def purge_disk(device): """ Remove partition table entries """ # wipe any file systems first for d in enumerate_disk(device): if d["type"] not in ["disk", "crypt"]: wipefs_cmd = [WIPEFS_CMD, "--all", "/dev/%s" % d["name"]] try: LOG.info("Purging filesystem on /dev/%s", d["name"]) subp.subp(wipefs_cmd) except Exception as e: raise RuntimeError( "Failed FS purge of /dev/%s" % d["name"] ) from e purge_disk_ptable(device) def get_partition_layout(table_type, size, layout): """ Call the appropriate function for creating the table definition. Returns the table definition This is a future proofing function. To add support for other layouts, simply add a "get_partition_%s_layout" function. """ if "mbr" == table_type: return get_partition_mbr_layout(size, layout) elif "gpt" == table_type: return get_partition_gpt_layout(size, layout) raise RuntimeError("Unable to determine table type") def read_parttbl(device): """ `Partprobe` is preferred over `blkdev` since it is more reliably able to probe the partition table. """ if PARTPROBE_CMD is not None: probe_cmd = [PARTPROBE_CMD, device] else: probe_cmd = [BLKDEV_CMD, "--rereadpt", device] util.udevadm_settle() try: subp.subp(probe_cmd) except Exception as e: util.logexc(LOG, "Failed reading the partition table %s" % e) util.udevadm_settle() def exec_mkpart_mbr(device, layout): """ Break out of mbr partition to allow for future partition types, i.e. gpt """ # Create the partitions prt_cmd = [SFDISK_CMD, "--force", device] try: subp.subp(prt_cmd, data="%s\n" % layout) except Exception as e: raise RuntimeError( "Failed to partition device %s\n%s" % (device, e) ) from e read_parttbl(device) def exec_mkpart_gpt(device, layout): try: subp.subp([SGDISK_CMD, "-Z", device]) for index, (partition_type, (start, end)) in enumerate(layout): index += 1 subp.subp( [ SGDISK_CMD, "-n", "{}:{}:{}".format(index, start, end), device, ] ) if partition_type is not None: # convert to a 4 char (or more) string right padded with 0 # 82 -> 8200. 'Linux' -> 'Linux' pinput = str(partition_type).ljust(4, "0") subp.subp( [SGDISK_CMD, "-t", "{}:{}".format(index, pinput), device] ) except Exception: LOG.warning("Failed to partition device %s", device) raise read_parttbl(device) def assert_and_settle_device(device): """Assert that device exists and settle so it is fully recognized.""" if not os.path.exists(device): util.udevadm_settle() if not os.path.exists(device): raise RuntimeError( "Device %s did not exist and was not created " "with a udevadm settle." % device ) # Whether or not the device existed above, it is possible that udev # events that would populate udev database (for reading by lsdname) have # not yet finished. So settle again. util.udevadm_settle() def mkpart(device, definition): """ Creates the partition table. Parameters: definition: dictionary describing how to create the partition. The following are supported values in the dict: overwrite: Should the partition table be created regardless of any pre-existing data? layout: the layout of the partition table table_type: Which partition table to use, defaults to MBR device: the device to work on. """ # ensure that we get a real device rather than a symbolic link assert_and_settle_device(device) device = os.path.realpath(device) LOG.debug("Checking values for %s definition", device) overwrite = definition.get("overwrite", False) layout = definition.get("layout", False) table_type = definition.get("table_type", "mbr") # Check if the default device is a partition or not LOG.debug("Checking against default devices") if (isinstance(layout, bool) and not layout) or not layout: LOG.debug("Device is not to be partitioned, skipping") return # Device is not to be partitioned # This prevents you from overwriting the device LOG.debug("Checking if device %s is a valid device", device) if not is_device_valid(device): raise RuntimeError( "Device {device} is not a disk device!".format(device=device) ) # Remove the partition table entries if isinstance(layout, str) and layout.lower() == "remove": LOG.debug("Instructed to remove partition table entries") purge_disk(device) return LOG.debug("Checking if device layout matches") if check_partition_layout(table_type, device, layout): LOG.debug("Device partitioning layout matches") return True LOG.debug("Checking if device is safe to partition") if not overwrite and (is_disk_used(device) or is_filesystem(device)): LOG.debug("Skipping partitioning on configured device %s", device) return LOG.debug("Checking for device size of %s", device) device_size = get_hdd_size(device) LOG.debug("Calculating partition layout") part_definition = get_partition_layout(table_type, device_size, layout) LOG.debug(" Layout is: %s", part_definition) LOG.debug("Creating partition table on %s", device) if "mbr" == table_type: exec_mkpart_mbr(device, part_definition) elif "gpt" == table_type: exec_mkpart_gpt(device, part_definition) else: raise RuntimeError("Unable to determine table type") LOG.debug("Partition table created for %s", device) def lookup_force_flag(fs): """ A force flag might be -F or -F, this look it up """ flags = { "ext": "-F", "btrfs": "-f", "xfs": "-f", "reiserfs": "-f", "swap": "-f", } if "ext" in fs.lower(): fs = "ext" if fs.lower() in flags: return flags[fs] LOG.warning("Force flag for %s is unknown.", fs) return "" def mkfs(fs_cfg): """ Create a file system on the device. label: defines the label to use on the device fs_cfg: defines how the filesystem is to look The following values are required generally: device: which device or cloud defined default_device filesystem: which file system type overwrite: indiscriminately create the file system partition: when device does not define a partition, setting this to a number will mean device + partition. When set to 'auto', the first free device or the first device which matches both label and type will be used. 'any' means the first filesystem that matches on the device. When 'cmd' is provided then no other parameter is required. """ label = fs_cfg.get("label") device = fs_cfg.get("device") partition = str(fs_cfg.get("partition", "any")) fs_type = fs_cfg.get("filesystem") fs_cmd = fs_cfg.get("cmd", []) fs_opts = fs_cfg.get("extra_opts", []) fs_replace = fs_cfg.get("replace_fs", False) overwrite = fs_cfg.get("overwrite", False) # ensure that we get a real device rather than a symbolic link assert_and_settle_device(device) device = os.path.realpath(device) # This allows you to define the default ephemeral or swap LOG.debug("Checking %s against default devices", device) if not partition or partition.isdigit(): # Handle manual definition of partition if partition.isdigit(): device = "%s%s" % (device, partition) LOG.debug( "Manual request of partition %s for %s", partition, device ) # Check to see if the fs already exists LOG.debug("Checking device %s", device) check_label, check_fstype, _ = check_fs(device) LOG.debug( "Device '%s' has check_label='%s' check_fstype=%s", device, check_label, check_fstype, ) if check_label == label and check_fstype == fs_type: LOG.debug("Existing file system found at %s", device) if not overwrite: LOG.debug("Device %s has required file system", device) return else: LOG.warning("Destroying filesystem on %s", device) else: LOG.debug("Device %s is cleared for formatting", device) elif partition and str(partition).lower() in ("auto", "any"): # For auto devices, we match if the filesystem does exist odevice = device LOG.debug("Identifying device to create %s filesystem on", label) # 'any' means pick the first match on the device with matching fs_type label_match = True if partition.lower() == "any": label_match = False device, reuse = find_device_node( device, fs_type=fs_type, label=label, label_match=label_match, replace_fs=fs_replace, ) LOG.debug("Automatic device for %s identified as %s", odevice, device) if reuse: LOG.debug("Found filesystem match, skipping formatting.") return if not reuse and fs_replace and device: LOG.debug("Replacing file system on %s as instructed.", device) if not device: LOG.debug( "No device available that matches request. " "Skipping fs creation for %s", fs_cfg, ) return elif not partition or str(partition).lower() == "none": LOG.debug("Using the raw device to place filesystem %s on", label) else: LOG.debug("Error in device identification handling.") return LOG.debug( "File system type '%s' with label '%s' will be created on %s", fs_type, label, device, ) # Make sure the device is defined if not device: LOG.warning("Device is not known: %s", device) return # Check that we can create the FS if not (fs_type or fs_cmd): raise RuntimeError( "No way to create filesystem '{label}'. fs_type or fs_cmd " "must be set.".format(label=label) ) # Create the commands shell = False if fs_cmd: fs_cmd = fs_cfg["cmd"] % { "label": label, "filesystem": fs_type, "device": device, } shell = True if overwrite: LOG.warning( "fs_setup:overwrite ignored because cmd was specified: %s", fs_cmd, ) if fs_opts: LOG.warning( "fs_setup:extra_opts ignored because cmd was specified: %s", fs_cmd, ) else: # Find the mkfs command mkfs_cmd = subp.which("mkfs.%s" % fs_type) if not mkfs_cmd: # for "mkswap" mkfs_cmd = subp.which("mk%s" % fs_type) if not mkfs_cmd: LOG.warning( "Cannot create fstype '%s'. No mkfs.%s command", fs_type, fs_type, ) return fs_cmd = [mkfs_cmd] if label: fs_cmd.extend(["-L", label]) # File systems that support the -F flag if overwrite or device_type(device) == "disk": force_flag = lookup_force_flag(fs_type) if force_flag: fs_cmd.append(force_flag) # Add the extends FS options if fs_opts: fs_cmd.extend(fs_opts) fs_cmd.append(device) LOG.debug("Creating file system %s on %s", label, device) LOG.debug(" Using cmd: %s", str(fs_cmd)) try: subp.subp(fs_cmd, shell=shell) except Exception as e: raise RuntimeError("Failed to exec of '%s':\n%s" % (fs_cmd, e)) from e