scan.py

#
# Project Kimchi
#
# Copyright IBM Corp, 2015-2016
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
#
import glob
import hashlib
import os.path
import shutil
import tempfile
import time

from wok.plugins.kimchi.isoinfo import IsoImage
from wok.plugins.kimchi.isoinfo import probe_iso
from wok.utils import wok_log


SCAN_IGNORE = ['/tmp/kimchi-scan-*']


class Scanner(object):
    SCAN_TTL = 300

    def __init__(self, record_clean_cb):
        self.clean_cb = record_clean_cb

    def delete(self):
        self.clean_stale(-1)

    def clean_stale(self, window=SCAN_TTL):
        """
        Clear scan pools generated before time window,
        Clear all scan pools if window is -1.
        """
        try:
            now = time.time()
            clean_list = glob.glob('/tmp/kimchi-scan-*')
            for d in clean_list:
                transient_pool = os.path.basename(
                    d).replace('kimchi-scan-', '')[0:-6]
                if now - os.path.getmtime(d) > window:
                    shutil.rmtree(d)
                    self.clean_cb(transient_pool)
        except OSError as e:
            msg = f'Exception {e} occured when cleaning stale pool, ignore'
            wok_log.debug(msg)

    def scan_dir_prepare(self, name):
        # clean stale scan storage pools
        self.clean_stale()
        return tempfile.mkdtemp(prefix='kimchi-scan-' + name, dir='/tmp')

    def start_scan(self, cb, params):
        def updater(iso_info):
            iso_name = os.path.basename(iso_info['path'])[:-3]

            duplicates = '%s/%s*' % (params['pool_path'], iso_name)
            for f in glob.glob(duplicates):
                iso_img = IsoImage(f)
                if (iso_info['distro'], iso_info['version']) == iso_img.probe():
                    return

            iso_path = (
                iso_name +
                hashlib.md5(iso_info['path'].encode('utf-8')).hexdigest() +
                '.iso'
            )
            link_name = os.path.join(
                params['pool_path'], os.path.basename(iso_path))
            os.symlink(iso_info['path'], link_name)

        ignore_paths = params.get('ignore_list', [])
        scan_params = dict(
            path=params['scan_path'],
            updater=updater,
            ignore_list=ignore_paths + SCAN_IGNORE,
        )
        probe_iso(None, scan_params)
        cb('', True)