#
# Copyright 2012-2016 Canonical Ltd.
#
# Authors:
#  James Page <james.page@ubuntu.com>
#  Paul Collins <paul.collins@canonical.com>
#  Chris MacNaughton <chris.macnaughton@canonical.com>
#

# Imports from ceph.py
import ctypes
import ctypes.util
import errno
import json
import subprocess
import time
import os
import re
import socket
import sys
import shutil
from charmhelpers.cli.host import mounts
from charmhelpers.core.host import (
    mkdir,
    chownr,
    cmp_pkgrevno,
    lsb_release,
    service_stop,
    service_restart)
from charms.reactive import is_state
from charmhelpers.core.hookenv import (
    log,
    ERROR,
    WARNING,
    DEBUG,
    cached,
    config,
    unit_get,
    status_set,
    relation_ids,
    related_units,
    relation_get,
    local_unit,
    network_get_primary_address,
)
from charmhelpers.fetch import (
    apt_cache,
    # apt_install,
    # filter_installed_packages
)
from charmhelpers.contrib.storage.linux.utils import (
    zap_disk,
    is_block_device,
    is_device_mounted,
)
# from utils import (
#     get_unit_hostname,
# )

from charmhelpers.contrib.network.ip import (
    get_address_in_network,
    get_ipv6_addr,
    format_ipv6_addr
)

# try:
#     import dns.resolver
# except ImportError:
#     apt_install(filter_installed_packages(['python-dnspython']),
#                 fatal=True)
#     import dns.resolver
import dns.resolver


def get_mon_hosts():
    hosts = []
    if is_state('ceph_mon.installed'):
        addr = get_public_addr()
        hosts.append('{}:6789'.format(format_ipv6_addr(addr) or addr))

    for relid in relation_ids('mon'):
        for unit in related_units(relid):
            addr = relation_get('ceph-public-address', unit, relid)
            if addr is not None:
                hosts.append('{}:6789'.format(
                    format_ipv6_addr(addr) or addr))

    hosts.sort()
    return hosts


def enable_pocket(pocket):
    apt_sources = "/etc/apt/sources.list"
    with open(apt_sources, "r") as sources:
        lines = sources.readlines()
    with open(apt_sources, "w") as sources:
        for line in lines:
            if pocket in line:
                sources.write(re.sub('^# deb', 'deb', line))
            else:
                sources.write(line)


@cached
def get_unit_hostname():
    return socket.gethostname()


@cached
def get_host_ip(hostname=None):
    if config('prefer-ipv6'):
        return get_ipv6_addr()[0]

    hostname = hostname or unit_get('private-address')
    try:
        # Test to see if already an IPv4 address
        socket.inet_aton(hostname)
        return hostname
    except socket.error:
        # This may throw an NXDOMAIN exception; in which case
        # things are badly broken so just let it kill the hook
        answers = dns.resolver.query(hostname, 'A')
        if answers:
            return answers[0].address


@cached
def get_public_addr():
    if config('ceph-public-network'):
        return get_network_addrs('ceph-public-network')[0]

    try:
        return network_get_primary_address('public')
    except NotImplementedError:
        log("network-get not supported", DEBUG)

    return get_host_ip()


@cached
def get_cluster_addr():
    if config('ceph-cluster-network'):
        return get_network_addrs('ceph-cluster-network')[0]

    try:
        return network_get_primary_address('cluster')
    except NotImplementedError:
        log("network-get not supported", DEBUG)

    return get_host_ip()


def get_networks(config_opt='ceph-public-network'):
    """Get all configured networks from provided config option.
    If public network(s) are provided, go through them and return those for
    which we have an address configured.
    """
    networks = config(config_opt)
    if networks:
        networks = networks.split()
        return [n for n in networks if get_address_in_network(n)]

    return []


def get_network_addrs(config_opt):
    """Get all configured public networks addresses.
    If public network(s) are provided, go through them and return the
    addresses we have configured on any of those networks.
    """
    addrs = []
    networks = config(config_opt)
    if networks:
        networks = networks.split()
        addrs = [get_address_in_network(n) for n in networks]
        addrs = [a for a in addrs if a]

    if not addrs:
        if networks:
            msg = ("Could not find an address on any of '%s' - resolve this "
                   "error to retry" % (networks))
            status_set('blocked', msg)
            raise Exception(msg)
        else:
            return [get_host_ip()]

    return addrs


def assert_charm_supports_ipv6():
    """Check whether we are able to support charms ipv6."""
    if lsb_release()['DISTRIB_CODENAME'].lower() < "trusty":
        raise Exception("IPv6 is not supported in the charms for Ubuntu "
                        "versions less than Trusty 14.04")


def get_peer_units():
    """
    Returns a dictionary of unit names from the mon peer relation with
    a flag indicating whether the unit has presented its address
    """
    units = {}
    units[local_unit()] = True
    for relid in relation_ids('mon'):
        for unit in related_units(relid):
            addr = relation_get('ceph-public-address', unit, relid)
            units[unit] = addr is not None
    return units


LEADER = 'leader'
PEON = 'peon'
QUORUM = [LEADER, PEON]

PACKAGES = ['ceph', 'gdisk', 'ntp', 'btrfs-tools', 'python-ceph', 'xfsprogs']


def ceph_user():
    if get_version() > 1:
        return 'ceph'
    else:
        return "root"


class CrushLocation(object):
    def __init__(self,
                 name,
                 identifier,
                 host,
                 rack,
                 row,
                 datacenter,
                 chassis,
                 root):
        self.name = name
        self.identifier = identifier
        self.host = host
        self.rack = rack
        self.row = row
        self.datacenter = datacenter
        self.chassis = chassis
        self.root = root

    def __str__(self):
        return "name: {} id: {} host: {} rack: {} row: {} datacenter: {} " \
               "chassis :{} root: {}".format(self.name, self.identifier,
                                             self.host, self.rack, self.row,
                                             self.datacenter, self.chassis,
                                             self.root)

    def __eq__(self, other):
        return not self.name < other.name and not other.name < self.name

    def __ne__(self, other):
        return self.name < other.name or other.name < self.name

    def __gt__(self, other):
        return self.name > other.name

    def __ge__(self, other):
        return not self.name < other.name

    def __le__(self, other):
        return self.name < other.name


def get_osd_tree(service):
    """
    Returns the current osd map in JSON.
    :return: List. :raise: ValueError if the monmap fails to parse.
      Also raises CalledProcessError if our ceph command fails
    """
    try:
        tree = subprocess.check_output(
            ['ceph', '--id', service,
             'osd', 'tree', '--format=json']).decode('utf-8')
        try:
            json_tree = json.loads(tree)
            crush_list = []
            # Make sure children are present in the json
            if not json_tree['nodes']:
                return None
            child_ids = json_tree['nodes'][0]['children']
            for child in json_tree['nodes']:
                if child['id'] in child_ids:
                    crush_list.append(
                        CrushLocation(
                            name=child.get('name'),
                            identifier=child['id'],
                            host=child.get('host'),
                            rack=child.get('rack'),
                            row=child.get('row'),
                            datacenter=child.get('datacenter'),
                            chassis=child.get('chassis'),
                            root=child.get('root')
                        )
                    )
            return crush_list
        except ValueError as v:
            log("Unable to parse ceph tree json: {}. Error: {}".format(
                tree, v.message))
            raise
    except subprocess.CalledProcessError as e:
        log("ceph osd tree command failed with message: {}".format(
            e.message))
        raise


def get_local_osd_ids():
    """
    This will list the /var/lib/ceph/osd/* directories and try
    to split the ID off of the directory name and return it in
    a list

    :return: list.  A list of osd identifiers :raise: OSError if
     something goes wrong with listing the directory.
    """
    osd_ids = []
    osd_path = os.path.join(os.sep, 'var', 'lib', 'ceph', 'osd')
    if os.path.exists(osd_path):
        try:
            dirs = os.listdir(osd_path)
            for osd_dir in dirs:
                osd_id = osd_dir.split('-')[1]
                osd_ids.append(osd_id)
        except OSError:
            raise
    return osd_ids


def get_local_mon_ids():
    """
    This will list the /var/lib/ceph/mon/* directories and try
    to split the ID off of the directory name and return it in
    a list

    :return: list.  A list of monitor identifiers :raise: OSError if
     something goes wrong with listing the directory.
    """
    mon_ids = []
    mon_path = os.path.join(os.sep, 'var', 'lib', 'ceph', 'mon')
    if os.path.exists(mon_path):
        try:
            dirs = os.listdir(mon_path)
            for mon_dir in dirs:
                # Basically this takes everything after ceph- as the monitor ID
                match = re.search('ceph-(?P<mon_id>.*)', mon_dir)
                if match:
                    mon_ids.append(match.group('mon_id'))
        except OSError:
            raise
    return mon_ids


def get_version():
    '''Derive Ceph release from an installed package.'''
    import apt_pkg as apt

    cache = apt_cache()
    package = "ceph"
    try:
        pkg = cache[package]
    except:
        # the package is unknown to the current apt cache.
        e = 'Could not determine version of package with no installation ' \
            'candidate: %s' % package
        error_out(e)

    if not pkg.current_ver:
        # package is known, but no version is currently installed.
        e = 'Could not determine version of uninstalled package: %s' % package
        error_out(e)

    vers = apt.upstream_version(pkg.current_ver.ver_str)

    # x.y match only for 20XX.X
    # and ignore patch level for other packages
    match = re.match('^(\d+)\.(\d+)', vers)

    if match:
        vers = match.group(0)
    return float(vers)


def error_out(msg):
    log("FATAL ERROR: %s" % msg,
        level=ERROR)
    sys.exit(1)


def is_quorum():
    asok = "/var/run/ceph/ceph-mon.{}.asok".format(get_unit_hostname())
    cmd = [
        "sudo",
        "-u",
        ceph_user(),
        "ceph",
        "--admin-daemon",
        asok,
        "mon_status"
    ]
    if os.path.exists(asok):
        try:
            result = json.loads(subprocess.check_output(cmd).decode('utf-8'))
        except subprocess.CalledProcessError:
            return False
        except ValueError:
            # Non JSON response from mon_status
            return False
        if result['state'] in QUORUM:
            return True
        else:
            return False
    else:
        return False


def is_leader():
    asok = "/var/run/ceph/ceph-mon.{}.asok".format(get_unit_hostname())
    cmd = [
        "sudo",
        "-u",
        ceph_user(),
        "ceph",
        "--admin-daemon",
        asok,
        "mon_status"
    ]
    if os.path.exists(asok):
        try:
            result = json.loads(subprocess.check_output(cmd).decode('utf-8'))
        except subprocess.CalledProcessError:
            return False
        except ValueError:
            # Non JSON response from mon_status
            return False
        if result['state'] == LEADER:
            return True
        else:
            return False
    else:
        return False


def wait_for_quorum():
    while not is_quorum():
        time.sleep(3)


def add_bootstrap_hint(peer):
    asok = "/var/run/ceph/ceph-mon.{}.asok".format(get_unit_hostname())
    cmd = [
        "sudo",
        "-u",
        ceph_user(),
        "ceph",
        "--admin-daemon",
        asok,
        "add_bootstrap_peer_hint",
        peer
    ]
    if os.path.exists(asok):
        # Ignore any errors for this call
        subprocess.call(cmd)


DISK_FORMATS = [
    'xfs',
    'ext4',
    'btrfs'
]

CEPH_PARTITIONS = [
    '4FBD7E29-9D25-41B8-AFD0-5EC00CEFF05D',  # ceph encrypted osd data
    '4FBD7E29-9D25-41B8-AFD0-062C0CEFF05D',  # ceph osd data
    '45B0969E-9B03-4F30-B4C6-B4B80CEFF106',  # ceph osd journal
]


def umount(mount_point):
    """
    This function unmounts a mounted directory forcibly.  This will
    be used for unmounting broken hard drive mounts which may hang.
    If umount returns EBUSY this will lazy unmount.
    :param mount_point: str.  A String representing the filesystem mount point
    :return: int.  Returns 0 on success.  errno otherwise.
    """
    libc_path = ctypes.util.find_library("c")
    libc = ctypes.CDLL(libc_path, use_errno=True)

    # First try to umount with MNT_FORCE
    ret = libc.umount(mount_point, 1)
    if ret < 0:
        err = ctypes.get_errno()
        if err == errno.EBUSY:
            # Detach from try.  IE lazy umount
            ret = libc.umount(mount_point, 2)
            if ret < 0:
                err = ctypes.get_errno()
                return err
            return 0
        else:
            return err
    return 0


def replace_osd(dead_osd_number,
                dead_osd_device,
                new_osd_device,
                osd_format,
                osd_journal,
                reformat_osd=False,
                ignore_errors=False):
    """
    This function will automate the replacement of a failed osd disk as much
    as possible. It will revoke the keys for the old osd, remove it from the
    crush map and then add a new osd into the cluster.
    :param dead_osd_number: The osd number found in ceph osd tree. Example: 99
    :param dead_osd_device: The physical device.  Example: /dev/sda
    :param osd_format:
    :param osd_journal:
    :param reformat_osd:
    :param ignore_errors:
    """
    host_mounts = mounts()
    mount_point = None
    for mount in host_mounts:
        if mount[1] == dead_osd_device:
            mount_point = mount[0]
    # need to convert dev to osd number
    # also need to get the mounted drive so we can tell the admin to
    # replace it
    try:
        # Drop this osd out of the cluster. This will begin a
        # rebalance operation
        status_set('maintenance', 'Removing osd {}'.format(dead_osd_number))
        subprocess.check_output(['ceph', 'osd', 'out',
                                 'osd.{}'.format(dead_osd_number)])

        # Kill the osd process if it's not already dead
        if systemd():
            service_stop('ceph-osd@{}'.format(dead_osd_number))
        else:
            subprocess.check_output(['stop', 'ceph-osd', 'id={}'.format(
                dead_osd_number)]),
        # umount if still mounted
        ret = umount(mount_point)
        if ret < 0:
            raise RuntimeError('umount {} failed with error: {}'.format(
                mount_point, os.strerror(ret)))
        # Clean up the old mount point
        shutil.rmtree(mount_point)
        subprocess.check_output(['ceph', 'osd', 'crush', 'remove',
                                 'osd.{}'.format(dead_osd_number)])
        # Revoke the OSDs access keys
        subprocess.check_output(['ceph', 'auth', 'del',
                                 'osd.{}'.format(dead_osd_number)])
        subprocess.check_output(['ceph', 'osd', 'rm',
                                 'osd.{}'.format(dead_osd_number)])
        status_set('maintenance', 'Setting up replacement osd {}'.format(
            new_osd_device))
        osdize(new_osd_device,
               osd_format,
               osd_journal,
               reformat_osd,
               ignore_errors)
    except subprocess.CalledProcessError as e:
        log('replace_osd failed with error: ' + e.output)


def is_osd_disk(dev):
    try:
        info = subprocess.check_output(['sgdisk', '-i', '1', dev]) \
            .decode('utf-8')
        info = info.split("\n")  # IGNORE:E1103
        for line in info:
            for ptype in CEPH_PARTITIONS:
                sig = 'Partition GUID code: {}'.format(ptype)
                if line.startswith(sig):
                    return True
    except subprocess.CalledProcessError:
        pass
    return False


def start_osds(devices):
    # Scan for ceph block devices
    rescan_osd_devices()
    if cmp_pkgrevno('ceph', "0.56.6") >= 0:
        # Use ceph-disk activate for directory based OSD's
        for dev_or_path in devices:
            if os.path.exists(dev_or_path) and os.path.isdir(dev_or_path):
                subprocess.check_call(['ceph-disk', 'activate', dev_or_path])


def rescan_osd_devices():
    cmd = [
        'udevadm', 'trigger',
        '--subsystem-match=block', '--action=add'
    ]

    subprocess.call(cmd)


_bootstrap_keyring = "/var/lib/ceph/bootstrap-osd/ceph.keyring"
_upgrade_keyring = "/var/lib/ceph/osd/ceph.client.osd-upgrade.keyring"


def is_bootstrapped():
    return os.path.exists(_bootstrap_keyring)


def wait_for_bootstrap():
    while (not is_bootstrapped()):
        time.sleep(3)


def import_osd_bootstrap_key(key):
    if not os.path.exists(_bootstrap_keyring):
        cmd = [
            "sudo",
            "-u",
            ceph_user(),
            'ceph-authtool',
            _bootstrap_keyring,
            '--create-keyring',
            '--name=client.bootstrap-osd',
            '--add-key={}'.format(key)
        ]
        subprocess.check_call(cmd)


def import_osd_upgrade_key(key):
    if not os.path.exists(_upgrade_keyring):
        cmd = [
            "sudo",
            "-u",
            ceph_user(),
            'ceph-authtool',
            _upgrade_keyring,
            '--create-keyring',
            '--name=client.osd-upgrade',
            '--add-key={}'.format(key)
        ]
        subprocess.check_call(cmd)


def generate_monitor_secret():
    cmd = [
        'ceph-authtool',
        '/dev/stdout',
        '--name=mon.',
        '--gen-key'
    ]
    res = subprocess.getoutput(' '.join(cmd))

    return "{}==".format(res.split('=')[1].strip())

# OSD caps taken from ceph-create-keys
_osd_bootstrap_caps = {
    'mon': [
        'allow command osd create ...',
        'allow command osd crush set ...',
        r'allow command auth add * osd allow\ * mon allow\ rwx',
        'allow command mon getmap'
    ]
}

_osd_bootstrap_caps_profile = {
    'mon': [
        'allow profile bootstrap-osd'
    ]
}


def parse_key(raw_key):
    # get-or-create appears to have different output depending
    # on whether its 'get' or 'create'
    # 'create' just returns the key, 'get' is more verbose and
    # needs parsing
    key = None
    if len(raw_key.splitlines()) == 1:
        key = raw_key
    else:
        for element in raw_key.splitlines():
            if 'key' in element:
                key = element.split(' = ')[1].strip()  # IGNORE:E1103
    return key


def get_osd_bootstrap_key():
    try:
        # Attempt to get/create a key using the OSD bootstrap profile first
        key = get_named_key('bootstrap-osd',
                            _osd_bootstrap_caps_profile)
    except:
        # If that fails try with the older style permissions
        key = get_named_key('bootstrap-osd',
                            _osd_bootstrap_caps)
    return key


_radosgw_keyring = "/etc/ceph/keyring.rados.gateway"


def import_radosgw_key(key):
    if not os.path.exists(_radosgw_keyring):
        cmd = [
            "sudo",
            "-u",
            ceph_user(),
            'ceph-authtool',
            _radosgw_keyring,
            '--create-keyring',
            '--name=client.radosgw.gateway',
            '--add-key={}'.format(key)
        ]
        subprocess.check_call(cmd)

# OSD caps taken from ceph-create-keys
_radosgw_caps = {
    'mon': ['allow rw'],
    'osd': ['allow rwx']
}
_upgrade_caps = {
    'mon': ['allow rwx']
}


def get_radosgw_key():
    return get_named_key('radosgw.gateway', _radosgw_caps)


_default_caps = {
    'mon': ['allow rw'],
    'osd': ['allow rwx']
}
admin_caps = {
    'mds': ['allow'],
    'mon': ['allow *'],
    'osd': ['allow *']
}
osd_upgrade_caps = {
    'mon': ['allow command "config-key"',
            'allow command "osd tree"',
            'allow command "config-key list"',
            'allow command "config-key put"',
            'allow command "config-key get"',
            'allow command "config-key exists"',
            ]
}


def get_upgrade_key():
    return get_named_key('upgrade-osd', _upgrade_caps)


def get_named_key(name, caps=None):
    caps = caps or _default_caps
    cmd = [
        "sudo",
        "-u",
        ceph_user(),
        'ceph',
        '--name', 'mon.',
        '--keyring',
        '/var/lib/ceph/mon/ceph-{}/keyring'.format(
            get_unit_hostname()
        ),
        'auth', 'get-or-create', 'client.{}'.format(name),
    ]
    # Add capabilities
    for subsystem, subcaps in caps.items():
        cmd.extend([
            subsystem,
            '; '.join(subcaps),
        ])
    return parse_key(subprocess.check_output(cmd)
                     .decode('utf-8').strip())  # IGNORE:E1103


def upgrade_key_caps(key, caps):
    """ Upgrade key to have capabilities caps """
    if not is_leader():
        # Not the MON leader OR not clustered
        return
    cmd = [
        "sudo", "-u", ceph_user(), 'ceph', 'auth', 'caps', key
    ]
    for subsystem, subcaps in caps.items():
        cmd.extend([subsystem, '; '.join(subcaps)])
    subprocess.check_call(cmd)


@cached
def systemd():
    return (lsb_release()['DISTRIB_CODENAME'] >= 'vivid')


def bootstrap_monitor_cluster(secret):
    hostname = get_unit_hostname()
    path = '/var/lib/ceph/mon/ceph-{}'.format(hostname)
    done = '{}/done'.format(path)
    if systemd():
        init_marker = '{}/systemd'.format(path)
    else:
        init_marker = '{}/upstart'.format(path)

    keyring = '/var/lib/ceph/tmp/{}.mon.keyring'.format(hostname)

    if os.path.exists(done):
        log('bootstrap_monitor_cluster: mon already initialized.')
    else:
        # Ceph >= 0.61.3 needs this for ceph-mon fs creation
        mkdir('/var/run/ceph', owner=ceph_user(),
              group=ceph_user(), perms=0o755)
        mkdir(path, owner=ceph_user(), group=ceph_user())
        mkdir("/var/lib/ceph/tmp", owner=ceph_user(), group=ceph_user())
        # end changes for Ceph >= 0.61.3
        try:
            subprocess.check_call(['ceph-authtool', keyring,
                                   '--create-keyring', '--name=mon.',
                                   '--add-key={}'.format(secret),
                                   '--cap', 'mon', 'allow *'])

            subprocess.check_call(['ceph-mon', '--mkfs',
                                   '-i', hostname,
                                   '--keyring', keyring])
            chownr(path, ceph_user(), ceph_user())
            with open(done, 'w'):
                pass
            with open(init_marker, 'w'):
                pass

            if systemd():
                subprocess.check_call(['systemctl', 'enable', 'ceph-mon'])
                service_restart('ceph-mon')
            else:
                service_restart('ceph-mon-all')
        except:
            raise
        finally:
            os.unlink(keyring)


def update_monfs():
    hostname = get_unit_hostname()
    monfs = '/var/lib/ceph/mon/ceph-{}'.format(hostname)
    if systemd():
        init_marker = '{}/systemd'.format(monfs)
    else:
        init_marker = '{}/upstart'.format(monfs)
    if os.path.exists(monfs) and not os.path.exists(init_marker):
        # Mark mon as managed by upstart so that
        # it gets start correctly on reboots
        with open(init_marker, 'w'):
            pass


def maybe_zap_journal(journal_dev):
    if is_osd_disk(journal_dev):
        log('Looks like {} is already an OSD data'
            ' or journal, skipping.'.format(journal_dev))
        return
    zap_disk(journal_dev)
    log("Zapped journal device {}".format(journal_dev))


def get_partitions(dev):
    cmd = ['partx', '--raw', '--noheadings', dev]
    try:
        out = subprocess.check_output(cmd).decode('utf-8').splitlines()
        log("get partitions: {}".format(out), level=DEBUG)
        return out
    except subprocess.CalledProcessError as e:
        log("Can't get info for {0}: {1}".format(dev, e.output))
        return []


def find_least_used_journal(journal_devices):
    usages = map(lambda a: (len(get_partitions(a)), a), journal_devices)
    least = min(usages, key=lambda t: t[0])
    return least[1]


def osdize(dev, osd_format, osd_journal, reformat_osd=False,
           ignore_errors=False, encrypt=False):
    if dev.startswith('/dev'):
        osdize_dev(dev, osd_format, osd_journal,
                   reformat_osd, ignore_errors, encrypt)
    else:
        osdize_dir(dev, encrypt)


def osdize_dev(dev, osd_format, osd_journal, reformat_osd=False,
               ignore_errors=False, encrypt=False):
    if not os.path.exists(dev):
        log('Path {} does not exist - bailing'.format(dev))
        return

    if not is_block_device(dev):
        log('Path {} is not a block device - bailing'.format(dev))
        return

    if is_osd_disk(dev) and not reformat_osd:
        log('Looks like {} is already an'
            ' OSD data or journal, skipping.'.format(dev))
        return

    if is_device_mounted(dev):
        log('Looks like {} is in use, skipping.'.format(dev))
        return

    status_set('maintenance', 'Initializing device {}'.format(dev))
    cmd = ['ceph-disk', 'prepare']
    # Later versions of ceph support more options
    if cmp_pkgrevno('ceph', '0.60') >= 0:
        if encrypt:
            cmd.append('--dmcrypt')
    if cmp_pkgrevno('ceph', '0.48.3') >= 0:
        if osd_format:
            cmd.append('--fs-type')
            cmd.append(osd_format)
        if reformat_osd:
            cmd.append('--zap-disk')
        cmd.append(dev)
        if osd_journal:
            least_used = find_least_used_journal(osd_journal)
            cmd.append(least_used)
    else:
        # Just provide the device - no other options
        # for older versions of ceph
        cmd.append(dev)
        if reformat_osd:
            zap_disk(dev)

    try:
        log("osdize cmd: {}".format(cmd))
        subprocess.check_call(cmd)
    except subprocess.CalledProcessError as e:
        if ignore_errors:
            log('Unable to initialize device: {}'.format(dev), WARNING)
        else:
            log('Unable to initialize device: {}'.format(dev), ERROR)
            raise e


def osdize_dir(path, encrypt=False):
    if os.path.exists(os.path.join(path, 'upstart')):
        log('Path {} is already configured as an OSD - bailing'.format(path))
        return

    if cmp_pkgrevno('ceph', "0.56.6") < 0:
        log('Unable to use directories for OSDs with ceph < 0.56.6',
            level=ERROR)
        raise

    mkdir(path, owner=ceph_user(), group=ceph_user(), perms=0o755)
    chownr('/var/lib/ceph', ceph_user(), ceph_user())
    cmd = [
        'sudo', '-u', ceph_user(),
        'ceph-disk',
        'prepare',
        '--data-dir',
        path
    ]
    if cmp_pkgrevno('ceph', '0.60') >= 0:
        if encrypt:
            cmd.append('--dmcrypt')
    log("osdize dir cmd: {}".format(cmd))
    subprocess.check_call(cmd)


def filesystem_mounted(fs):
    return subprocess.call(['grep', '-wqs', fs, '/proc/mounts']) == 0


def get_running_mds():
    """Returns a list of the pids of the current running MDS daemons"""
    cmd = ['pgrep', 'ceph-mds']
    try:
        result = subprocess.check_output(cmd).decode('utf-8')
        return result.split()
    except subprocess.CalledProcessError:
        return []


def get_running_osds():
    """Returns a list of the pids of the current running OSD daemons"""
    cmd = ['pgrep', 'ceph-osd']
    try:
        result = subprocess.check_output(cmd).decode('utf-8')
        return result.split()
    except subprocess.CalledProcessError:
        return []