# 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 sys import threading import re import struct from typing import Dict, List # 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(r'^\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/ld.so.cache', '/etc/ld.so.cache', '--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()