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"""Common python utilities for storage providers"""
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from charmhelpers.core import hookenv
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from stat import S_ISBLK, ST_MODE
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CHARM_DIR = os.environ.get("CHARM_DIR")
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FSTAB_FILE = "/etc/fstab"
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def log(message, level=None):
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"""Quaint little log wrapper for juju logging"""
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hookenv.log(message, level)
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"""Get the storage charm's provider type as set within it's config.yaml"""
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provider = hookenv.config("provider")
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"Error: no provider defined in storage charm config",
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"""Return True if the defined mountpoint is mounted"""
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mountpoint = hookenv.relation_get("mountpoint")
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log("INFO: No mountpoint defined by relation assuming not mounted.")
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return os.path.ismount(mountpoint)
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"""Unmount the relation-requested C{mountpoint}"""
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mountpoint = hookenv.relation_get("mountpoint")
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log("INFO: No mountpoint defined by relation no unmount performed.")
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log("%s is not mounted, Done." % mountpoint)
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for x in range(0, 20):
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if subprocess.call(["umount", mountpoint]) == 0:
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log("Unmounted %s, Done" % mountpoint)
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else: # Then device is in use let's report the offending process
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process_name = subprocess.check_output(
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"lsof %s | awk '(NR == 2){print $1}'" % mountpoint)
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log("WARNING: umount %s failed. Device in use by (%s)" %
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(mountpoint, process_name.strip()))
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"ERROR: Unmount failed, leaving relation in errored state",
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def _assert_block_device(device_path):
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"""C{device_path} is a valid block device or exit in error"""
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for x in range(0, 10):
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if not os.path.exists(device_path):
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log("WARNING: %s does not exist" % device_path)
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mode = os.stat(device_path)[ST_MODE]
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"DEBUG: block device found. Proceeding.",
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log("ERROR: %s is not a block device." % device_path)
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def _set_label(device_path, label):
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"""Set label if necessary on C{device_path}"""
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if not os.path.exists(device_path):
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log("ERROR: Cannot set label of %s. Path does not exist" % device_path)
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current_label = subprocess.check_output(
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"e2label %s" % device_path, shell=True)
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current_label = current_label.strip()
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if current_label == label:
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# Label already set, return
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log("WARNING: %s had label=%s, overwriting with label=%s" %
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(device_path, current_label, label))
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subprocess.check_call(
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"e2label %s %s" % (device_path, label), shell=True)
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def _read_partition_table(device_path):
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"""Call blockdev to read a valid partition table and return exit code"""
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return subprocess.call(
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"blockdev --rereadpt %s" % device_path, shell=True)
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def _assert_fstype(device_path, fstype):
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"""Return C{True} if a filesystem is of type C{fstype}"""
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command = "file -s %s | egrep -q %s" % (device_path, fstype)
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return subprocess.call(command, shell=True) == 0
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def _format_device(device_path):
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Create an ext4 partition, if needed, for C{device_path} and fsck that
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result = _read_partition_table(device_path)
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log("INFO: %s is busy, no fsck performed. Assuming formatted." %
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# Create an ext4 filesystem if NOT already present
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# use e.g. LABEl=vol-000012345
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if _assert_fstype(device_path, "ext4"):
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log("%s already formatted - skipping mkfs.ext4." % device_path)
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command = "mkfs.ext4 %s" % device_path
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log("NOTICE: Running: %s" % command)
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subprocess.check_call(command, shell=True)
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if subprocess.call("fsck -p %s" % device_path, shell=True) != 0:
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log("ERROR: fsck -p %s failed" % device_path)
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def mount_volume(device_path=None):
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Mount the attached volume, nfs or blockstoragebroker type, to the principal
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requested C{mountpoint}.
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If the C{mountpoint} required relation data does not exist, log the
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issue and exit. Otherwise attempt to initialize and mount the blockstorage
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mountpoint = hookenv.relation_get("mountpoint")
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log("No mountpoint defined by relation. Cannot mount volume yet.")
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log("Volume (%s) already mounted" % mountpoint)
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# publish changes to data relation and exit
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for relid in hookenv.relation_ids("data"):
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hookenv.relation_set(
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relid, relation_settings={"mountpoint": mountpoint})
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provider = get_provider()
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if provider == "nfs":
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relids = hookenv.relation_ids("nfs")
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for unit in hookenv.related_units(relid):
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relation = hookenv.relation_get(unit=unit, rid=relid)
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# XXX Only handle 1 related nfs unit. No nfs cluster support
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nfs_server = relation.get("private-address", None)
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nfs_path = relation.get("mountpoint", None)
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fstype = relation.get("fstype", None)
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options = relation.get("options", "default")
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if None in [nfs_server, nfs_path, fstype]:
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log("ERROR: Missing required relation values. "
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"nfs-relation-changed hook needs to run first.",
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device_path = "%s:%s" % (nfs_server, nfs_path)
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elif provider == "blockstoragebroker":
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if device_path is None:
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log("ERROR: No persistent nova device provided by "
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"blockstoragebroker.", hookenv.ERROR)
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_assert_block_device(device_path)
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_format_device(device_path)
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_set_label(device_path, mountpoint)
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fstype = subprocess.check_output(
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"blkid -o value -s TYPE %s" % device_path, shell=True).strip()
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log("ERROR: Unknown provider %s. Cannot mount volume." % hookenv.ERROR)
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if not os.path.exists(mountpoint):
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os.makedirs(mountpoint)
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options_string = "" if options == "default" else " -o %s" % options
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command = "mount -t %s%s %s %s" % (
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fstype, options_string, device_path, mountpoint)
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subprocess.check_call(command, shell=True)
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log("Mount (%s) successful" % mountpoint)
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with open(FSTAB_FILE, "a") as output_file:
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"%s %s %s %s 0 0" % (device_path, mountpoint, fstype, options))
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# publish changes to data relation and exit
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for relid in hookenv.relation_ids("data"):
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hookenv.relation_set(
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relid, relation_settings={"mountpoint": mountpoint})
added
removed
hooks/common_util.py
