zuul/zuul/driver/bubblewrap/__init__.py

275 lines
9.1 KiB
Python

# Copyright 2012 Hewlett-Packard Development Company, L.P.
# Copyright 2013 OpenStack Foundation
# Copyright 2016 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import argparse
import fcntl
import grp
import logging
import os
import psutil
import pwd
import shlex
import subprocess
import sys
import threading
import re
import struct
from typing import Dict, List # flake8: noqa
from zuul.driver import (Driver, WrapperInterface)
from zuul.execution_context import BaseExecutionContext
class WrappedPopen(object):
def __init__(self, command, fds):
self.command = command
self.fds = fds
def __call__(self, args, *sub_args, **kwargs):
try:
args = self.command + args
if kwargs.get('close_fds') or sys.version_info.major >= 3:
# The default in py3 is close_fds=True, so we need to pass
# our open fds in. However, this can only work right in
# py3.2 or later due to the lack of 'pass_fds' in prior
# versions. So until we are py3 only we can only bwrap
# things that are close_fds=False
pass_fds = list(kwargs.get('pass_fds', []))
for fd in self.fds:
if fd not in pass_fds:
pass_fds.append(fd)
kwargs['pass_fds'] = pass_fds
proc = psutil.Popen(args, *sub_args, **kwargs)
finally:
self.__del__()
return proc
def __del__(self):
for fd in self.fds:
try:
os.close(fd)
except OSError:
pass
self.fds = []
class BubblewrapExecutionContext(BaseExecutionContext):
log = logging.getLogger("zuul.BubblewrapExecutionContext")
def __init__(self, bwrap_command, ro_paths, rw_paths, secrets):
self.bwrap_command = bwrap_command
self.mounts_map = {'ro': ro_paths, 'rw': rw_paths}
self.secrets = secrets
def startPipeWriter(self, pipe, data):
# In case we have a large amount of data to write through a
# pipe, spawn a thread to handle the writes.
t = threading.Thread(target=self._writer, args=(pipe, data))
t.daemon = True
t.start()
def _writer(self, pipe, data):
os.write(pipe, data)
os.close(pipe)
def setpag(self):
# If we are on a system with AFS, ensure that each playbook
# invocation ends up in its own PAG.
# http://asa.scripts.mit.edu/trac/attachment/ticket/145/setpag.txt#L315
if os.path.exists("/proc/fs/openafs/afs_ioctl"):
fcntl.ioctl(open("/proc/fs/openafs/afs_ioctl"), 0x40084301,
struct.pack("lllll", 0, 0, 0, 0, 21))
def getPopen(self, **kwargs):
self.setpag()
# Set zuul_dir if it was not passed in
if 'zuul_dir' in kwargs:
zuul_dir = kwargs['zuul_dir']
else:
zuul_python_dir = os.path.dirname(sys.executable)
# We want the dir directly above bin to get the whole venv
zuul_dir = os.path.normpath(os.path.join(zuul_python_dir, '..'))
bwrap_command = list(self.bwrap_command)
if not zuul_dir.startswith('/usr'):
bwrap_command.extend(['--ro-bind', zuul_dir, zuul_dir])
for mount_type in ('ro', 'rw'):
bind_arg = '--ro-bind' if mount_type == 'ro' else '--bind'
for bind in self.mounts_map[mount_type]:
bwrap_command.extend([bind_arg, bind, bind])
# A list of file descriptors which must be held open so that
# bwrap may read from them.
read_fds = []
# Need users and groups
uid = os.getuid()
passwd = list(pwd.getpwuid(uid))
# Replace our user's actual home directory with the work dir.
passwd = passwd[:5] + [kwargs['work_dir']] + passwd[6:]
passwd_bytes = b':'.join(
['{}'.format(x).encode('utf8') for x in passwd])
(passwd_r, passwd_w) = os.pipe()
os.write(passwd_w, passwd_bytes)
os.write(passwd_w, b'\n')
os.close(passwd_w)
read_fds.append(passwd_r)
gid = os.getgid()
group = grp.getgrgid(gid)
group_bytes = b':'.join(
['{}'.format(x).encode('utf8') for x in group])
group_r, group_w = os.pipe()
os.write(group_w, group_bytes)
os.write(group_w, b'\n')
os.close(group_w)
read_fds.append(group_r)
# Create a tmpfs for each directory which holds secrets, and
# tell bubblewrap to write the contents to a file therein.
secret_dirs = set()
for fn, content in self.secrets.items():
secret_dir = os.path.dirname(fn)
if secret_dir not in secret_dirs:
bwrap_command.extend(['--tmpfs', secret_dir])
secret_dirs.add(secret_dir)
secret_r, secret_w = os.pipe()
self.startPipeWriter(secret_w, content.encode('utf8'))
bwrap_command.extend(['--file', str(secret_r), fn])
read_fds.append(secret_r)
kwargs = dict(kwargs) # Don't update passed in dict
kwargs['uid'] = uid
kwargs['gid'] = gid
kwargs['uid_fd'] = passwd_r
kwargs['gid_fd'] = group_r
command = [x.format(**kwargs) for x in bwrap_command]
self.log.debug("Bubblewrap command: %s",
" ".join(shlex.quote(c) for c in command))
wrapped_popen = WrappedPopen(command, read_fds)
return wrapped_popen
class BubblewrapDriver(Driver, WrapperInterface):
log = logging.getLogger("zuul.BubblewrapDriver")
name = 'bubblewrap'
release_file_re = re.compile('^\W+-release$')
def __init__(self):
self.bwrap_command = self._bwrap_command()
def reconfigure(self, tenant):
pass
def stop(self):
pass
def _bwrap_command(self):
bwrap_command = [
'bwrap',
'--dir', '/tmp',
'--tmpfs', '/tmp',
'--dir', '/var',
'--dir', '/var/tmp',
'--dir', '/run/user/{uid}',
'--ro-bind', '/usr', '/usr',
'--ro-bind', '/lib', '/lib',
'--ro-bind', '/bin', '/bin',
'--ro-bind', '/sbin', '/sbin',
'--ro-bind', '/etc/resolv.conf', '/etc/resolv.conf',
'--ro-bind', '/etc/hosts', '/etc/hosts',
'--ro-bind', '/etc/localtime', '/etc/localtime',
'--ro-bind', '{ssh_auth_sock}', '{ssh_auth_sock}',
'--bind', '{work_dir}', '{work_dir}',
'--proc', '/proc',
'--dev', '/dev',
'--chdir', '{work_dir}',
'--unshare-all',
'--share-net',
'--die-with-parent',
'--uid', '{uid}',
'--gid', '{gid}',
'--file', '{uid_fd}', '/etc/passwd',
'--file', '{gid_fd}', '/etc/group',
]
for path in ['/lib64',
'/etc/nsswitch.conf',
'/etc/lsb-release.d',
'/etc/alternatives',
'/etc/ssl/certs',
]:
if os.path.exists(path):
bwrap_command.extend(['--ro-bind', path, path])
for fn in os.listdir('/etc'):
if self.release_file_re.match(fn):
path = os.path.join('/etc', fn)
bwrap_command.extend(['--ro-bind', path, path])
return bwrap_command
def getExecutionContext(self, ro_paths=None, rw_paths=None, secrets=None):
if not ro_paths:
ro_paths = []
if not rw_paths:
rw_paths = []
if not secrets:
secrets = {}
return BubblewrapExecutionContext(
self.bwrap_command,
ro_paths, rw_paths,
secrets)
def main(args=None):
logging.basicConfig(level=logging.DEBUG)
driver = BubblewrapDriver()
parser = argparse.ArgumentParser()
parser.add_argument('--ro-paths', nargs='+')
parser.add_argument('--rw-paths', nargs='+')
parser.add_argument('--secret', nargs='+')
parser.add_argument('work_dir')
parser.add_argument('run_args', nargs='+')
cli_args = parser.parse_args()
ssh_auth_sock = os.environ.get('SSH_AUTH_SOCK')
secrets = {}
if cli_args.secret:
for secret in cli_args.secret:
fn, content = secret.split('=', 1)
secrets[fn]=content
context = driver.getExecutionContext(
cli_args.ro_paths, cli_args.rw_paths,
secrets)
popen = context.getPopen(work_dir=cli_args.work_dir,
ssh_auth_sock=ssh_auth_sock)
x = popen(cli_args.run_args)
x.wait()
if __name__ == '__main__':
main()