autopkgtest 3.6jessie1 / usr / bin / adt-virt-schroot

#!/usr/bin/python3
#
# adt-virt-schroot is part of autopkgtest
# autopkgtest is a tool for testing Debian binary packages
#
# autopkgtest is Copyright (C) 2006-2007 Canonical Ltd.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# See the file CREDITS for a full list of credits information (often
# installed as /usr/share/doc/autopkgtest/CREDITS).

import sys
import os
import re
import grp
import pwd
import subprocess
import time
import argparse

try:
    our_base = os.environ['AUTOPKGTEST_BASE'] + '/lib'
except KeyError:
    our_base = '/usr/share/autopkgtest/python'
sys.path.insert(1, our_base)

import VirtSubproc
import adtlog


capabilities = ['revert']

schroot = None
sessid = None
rootdir = None


def pw_uid(exp_name):
    try:
        return pwd.getpwnam(exp_name).pw_uid
    except KeyError:
        return None


def gr_gid(exp_name):
    try:
        return grp.getgrnam(exp_name).gr_gid
    except KeyError:
        return None


def match(exp_names, ids, extract_id):
    for exp_name in [n for n in exp_names.split(',') if n]:
        if extract_id(exp_name) in ids:
            return True
    return False


def parse_args():
    global schroot, sessid

    parser = argparse.ArgumentParser(fromfile_prefix_chars='@')
    parser.add_argument('-d', '--debug', action='store_true',
                        help='Enable debugging output')
    parser.add_argument('-s', '--session-id',
                        help='custom schroot session ID for easy identification '
                        'in "schroot --list --all-sessions"')
    parser.add_argument('schroot', help='name of schroot')

    args = parser.parse_args()
    sessid = args.session_id
    schroot = args.schroot
    if args.debug:
        adtlog.verbosity = 2

    info = VirtSubproc.check_exec(['schroot', '--config', '--chroot', schroot],
                                  downp=False, outp=True)
    cfg = {}
    ignore_re = re.compile('\#|\[|\s*$')
    for entry in info.split("\n"):
        if ignore_re.match(entry):
            continue
        (key, val) = entry.split("=", 2)
        cfg[key] = val

    adtlog.debug('schroot config: %s' % cfg)

    # we don't want to clobber non-ephemeral schroots
    if cfg['type'] == 'directory' and cfg.get('union-type', 'none') in ('', 'none'):
        VirtSubproc.bomb(
            'adt-virt-schroot requires ephemeral schroot sessions. Set a '
            '"union-type" or use a tarball schroot')

    if (match(cfg['root-users'], [os.getuid()], pw_uid) or
            match(cfg['root-groups'], [os.getgid()] + os.getgroups(), gr_gid) or
            os.getuid() == 0):
        adtlog.debug('have "root-on-testbed" capability')
        capabilities.append('root-on-testbed')

    if os.geteuid() != 0:
        username = pwd.getpwuid(os.geteuid()).pw_name
        capabilities.append('suggested-normal-user=' + username)


def hook_open():
    global schroot, sessid
    sessid = VirtSubproc.check_exec(['schroot', '--quiet', '--begin-session',
                                     '--chroot', schroot] +
                                    (sessid and ['--session-name', sessid] or []),
                                    outp=True)
    VirtSubproc.auxverb = ['schroot', '--run-session', '--quiet',
                           '--directory=/', '--chroot', sessid]
    if 'root-on-testbed' in capabilities:
        VirtSubproc.auxverb += ['--user=root']
    VirtSubproc.auxverb += ['--']


def hook_downtmp(path):
    global capabilities

    d = VirtSubproc.downtmp_mktemp(path)

    # determine mount location
    # FIXME: "schroot --location -c sessid" really ought to work, but fails; so
    # grep from --all-sessions until this gets fixed
    out = VirtSubproc.check_exec(['schroot', '--location', '--all-sessions'],
                                 downp=False, outp=True).strip()
    for l in out.splitlines():
        if sessid in l:
            location = l
            adtlog.debug('location of schroot session: %s' % location)
            break
    else:
        VirtSubproc.bomb('could not find our session in "%s"' % out)
    downtmp_host = '%s/%s' % (location, d)
    if os.access(downtmp_host, os.W_OK):
        adtlog.debug('%s is writable, registering as downtmp_host' % downtmp_host)
        capabilities.append('downtmp-host=' + downtmp_host)
    else:
        adtlog.debug('%s is not writable, downtmp_host not supported' % downtmp_host)

    # verify that we have /proc
    (rc, out, err) = VirtSubproc.execute_timeout(
        None, 5, VirtSubproc.auxverb + ['mountpoint', '/proc'],
        stdout=subprocess.PIPE)
    if rc != 0:
        VirtSubproc.bomb('Misconfigured schroot: /proc is not mounted')

    return d


def hook_revert():
    hook_cleanup()
    hook_open()


def hook_cleanup():
    global schroot, sessid, capabilities
    VirtSubproc.downtmp_remove()
    # sometimes fails on EBUSY
    retries = 10
    while retries > 0:
        if VirtSubproc.execute_timeout(
                None, 30, ['schroot', '--quiet', '--end-session', '--chroot', sessid])[0] == 0:
            break
        retries -= 1
        adtlog.info('schroot --end-session failed, retrying')
        time.sleep(1)
    else:
        adtlog.warning('schroot --end-session failed repeatedly;'
                       'please clean up manually')

    capabilities = [c for c in capabilities if not c.startswith('downtmp-host')]


def hook_forked_inchild():
    pass


def hook_capabilities():
    return capabilities


parse_args()
VirtSubproc.main()