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# Copyright 2013 Canonical Ltd. This software is licensed under the
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# GNU Affero General Public License version 3 (see the file LICENSE).
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"""Management of iSCSI targets for the ephemerals import script."""
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from __future__ import (
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from textwrap import dedent
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from provisioningserver.kernel_opts import (
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ISCSI_TARGET_NAME_PREFIX,
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from provisioningserver.utils import (
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call_capture_and_check,
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# Basic tgt-admin command line.
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TGT_ADMIN = ["tgt-admin", "--conf", "/etc/tgt/targets.conf"]
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# Template for the tgt.conf file in the data directory.
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DATA_DIR_TGT_CONF_TEMPLATE = dedent("""\
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# Template for individual tgt.conf files in target directories.
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TGT_CONF_TEMPLATE = dedent("""\
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<target {prefix}:{{target_name}}>
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backing-store "{{image}}"
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""").format(prefix=ISCSI_TARGET_NAME_PREFIX)
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INFO_TEMPLATE = dedent("""\
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def tgt_conf_d(data_dir):
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"""Return the path of a data directory's configuration directory."""
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return os.path.abspath(os.path.join(data_dir, 'tgt.conf.d'))
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def get_conf_path(data_dir, config_name):
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"""Return the path for an iSCSI config file.
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:param data_dir: Base data directory. The config should be in its
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`tgt.conf.d` subdirectory.
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:param config_name: Base name for the config. A ".conf" suffix will be
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return os.path.join(tgt_conf_d(data_dir), "%s.conf" % config_name)
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def get_target_name(release, version, arch, version_name):
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"""Compose a target's name based on its parameters.
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The `**kwargs` are inert. They are only here for calling convenience.
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return '-'.join(['maas', release, version, arch, version_name])
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def tgt_admin_delete(name):
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"""Delete a target using `tgt-admin`."""
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call_and_check(TGT_ADMIN + ["--delete", prefix_target_name(name)])
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class TargetNotCreated(RuntimeError):
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"""tgt-admin failed to create a target."""
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def target_exists(full_name):
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"""Run `tgt --show` to determine whether the given target exists.
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:param full_name: Full target name, including `ISCSI_TARGET_NAME_PREFIX`.
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status = call_capture_and_check(TGT_ADMIN + ["--show"])
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regex = b'^Target [0-9]+: %s\\s*$' % re.escape(full_name).encode('ascii')
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match = re.search(regex, status, flags=re.MULTILINE)
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return match is not None
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def tgt_admin_update(target_dir, target_name):
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"""Update a target using `tgt-admin`.
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Actually we use this to add new targets.
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full_name = prefix_target_name(target_name)
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call_and_check(TGT_ADMIN + ["--update", full_name])
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# Check that the target was really created.
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# Reportedly tgt-admin tends to return 0 even when it fails, so check
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if not target_exists(full_name):
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raise TargetNotCreated("Failed tgt-admin add for %s" % full_name)
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def set_up_data_dir(data_dir):
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"""Create a data directory and its configuration directory."""
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ensure_dir(tgt_conf_d(data_dir))
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os.path.join(data_dir, 'tgt.conf'),
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DATA_DIR_TGT_CONF_TEMPLATE.format(path=tgt_conf_d(data_dir)))
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def write_info_file(target_dir, target_name, release, label, serial, arch):
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"""Write the `info` file based on the given parameters."""
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text = INFO_TEMPLATE.format(
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release=release, label=label, serial=serial, arch=arch,
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info_file = os.path.join(target_dir, 'info')
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write_text_file(info_file, text)
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def clean_up_info_file(target_dir):
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"""To be called in the event of failure: move `info` file out of the way.
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The `info` file will be renamed `info.failed`, in the same directory, and
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any previously existing `info.failed` file is removed.
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info_file = os.path.join(target_dir, 'info')
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if not os.path.exists(info_file):
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failed_file = info_file + '.failed'
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if os.path.isfile(failed_file):
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os.remove(failed_file)
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shutil.move(info_file, failed_file)
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def write_conf(path, target_name, image):
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"""Write a `tgt.conf` file."""
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text = TGT_CONF_TEMPLATE.format(target_name=target_name, image=image)
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write_text_file(path, text)
added
removed
src/provisioningserver/import_images/tgt.py
