xref: /openbmc/qemu/tests/vm/basevm.py (revision 7acafcfa)
1#
2# VM testing base class
3#
4# Copyright 2017-2019 Red Hat Inc.
5#
6# Authors:
7#  Fam Zheng <famz@redhat.com>
8#  Gerd Hoffmann <kraxel@redhat.com>
9#
10# This code is licensed under the GPL version 2 or later.  See
11# the COPYING file in the top-level directory.
12#
13
14import os
15import re
16import sys
17import socket
18import logging
19import time
20import datetime
21sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
22from qemu.accel import kvm_available
23from qemu.machine import QEMUMachine
24import subprocess
25import hashlib
26import argparse
27import atexit
28import tempfile
29import shutil
30import multiprocessing
31import traceback
32import shlex
33
34SSH_KEY_FILE = os.path.join(os.path.dirname(__file__),
35               "..", "keys", "id_rsa")
36SSH_PUB_KEY_FILE = os.path.join(os.path.dirname(__file__),
37                   "..", "keys", "id_rsa.pub")
38
39# This is the standard configuration.
40# Any or all of these can be overridden by
41# passing in a config argument to the VM constructor.
42DEFAULT_CONFIG = {
43    'cpu'             : "max",
44    'machine'         : 'pc',
45    'guest_user'      : "qemu",
46    'guest_pass'      : "qemupass",
47    'root_pass'       : "qemupass",
48    'ssh_key_file'    : SSH_KEY_FILE,
49    'ssh_pub_key_file': SSH_PUB_KEY_FILE,
50    'memory'          : "4G",
51    'extra_args'      : [],
52    'qemu_args'       : "",
53    'dns'             : "",
54    'ssh_port'        : 0,
55    'install_cmds'    : "",
56    'boot_dev_type'   : "block",
57    'ssh_timeout'     : 1,
58}
59BOOT_DEVICE = {
60    'block' :  "-drive file={},if=none,id=drive0,cache=writeback "\
61               "-device virtio-blk,drive=drive0,bootindex=0",
62    'scsi'  :  "-device virtio-scsi-device,id=scsi "\
63               "-drive file={},format=raw,if=none,id=hd0 "\
64               "-device scsi-hd,drive=hd0,bootindex=0",
65}
66class BaseVM(object):
67
68    envvars = [
69        "https_proxy",
70        "http_proxy",
71        "ftp_proxy",
72        "no_proxy",
73    ]
74
75    # The script to run in the guest that builds QEMU
76    BUILD_SCRIPT = ""
77    # The guest name, to be overridden by subclasses
78    name = "#base"
79    # The guest architecture, to be overridden by subclasses
80    arch = "#arch"
81    # command to halt the guest, can be overridden by subclasses
82    poweroff = "poweroff"
83    # enable IPv6 networking
84    ipv6 = True
85    # This is the timeout on the wait for console bytes.
86    socket_timeout = 120
87    # Scale up some timeouts under TCG.
88    # 4 is arbitrary, but greater than 2,
89    # since we found we need to wait more than twice as long.
90    tcg_ssh_timeout_multiplier = 4
91    def __init__(self, args, config=None):
92        self._guest = None
93        self._genisoimage = args.genisoimage
94        self._build_path = args.build_path
95        self._efi_aarch64 = args.efi_aarch64
96        # Allow input config to override defaults.
97        self._config = DEFAULT_CONFIG.copy()
98        if config != None:
99            self._config.update(config)
100        self.validate_ssh_keys()
101        self._tmpdir = os.path.realpath(tempfile.mkdtemp(prefix="vm-test-",
102                                                         suffix=".tmp",
103                                                         dir="."))
104        atexit.register(shutil.rmtree, self._tmpdir)
105        # Copy the key files to a temporary directory.
106        # Also chmod the key file to agree with ssh requirements.
107        self._config['ssh_key'] = \
108            open(self._config['ssh_key_file']).read().rstrip()
109        self._config['ssh_pub_key'] = \
110            open(self._config['ssh_pub_key_file']).read().rstrip()
111        self._ssh_tmp_key_file = os.path.join(self._tmpdir, "id_rsa")
112        open(self._ssh_tmp_key_file, "w").write(self._config['ssh_key'])
113        subprocess.check_call(["chmod", "600", self._ssh_tmp_key_file])
114
115        self._ssh_tmp_pub_key_file = os.path.join(self._tmpdir, "id_rsa.pub")
116        open(self._ssh_tmp_pub_key_file,
117             "w").write(self._config['ssh_pub_key'])
118
119        self.debug = args.debug
120        self._console_log_path = None
121        if args.log_console:
122                self._console_log_path = \
123                         os.path.join(os.path.expanduser("~/.cache/qemu-vm"),
124                                      "{}.install.log".format(self.name))
125        self._stderr = sys.stderr
126        self._devnull = open(os.devnull, "w")
127        if self.debug:
128            self._stdout = sys.stdout
129        else:
130            self._stdout = self._devnull
131        netdev = "user,id=vnet,hostfwd=:127.0.0.1:{}-:22"
132        self._args = [ \
133            "-nodefaults", "-m", self._config['memory'],
134            "-cpu", self._config['cpu'],
135            "-netdev",
136            netdev.format(self._config['ssh_port']) +
137            (",ipv6=no" if not self.ipv6 else "") +
138            (",dns=" + self._config['dns'] if self._config['dns'] else ""),
139            "-device", "virtio-net-pci,netdev=vnet",
140            "-vnc", "127.0.0.1:0,to=20"]
141        if args.jobs and args.jobs > 1:
142            self._args += ["-smp", "%d" % args.jobs]
143        if kvm_available(self.arch):
144            self._args += ["-enable-kvm"]
145        else:
146            logging.info("KVM not available, not using -enable-kvm")
147        self._data_args = []
148
149        if self._config['qemu_args'] != None:
150            qemu_args = self._config['qemu_args']
151            qemu_args = qemu_args.replace('\n',' ').replace('\r','')
152            # shlex groups quoted arguments together
153            # we need this to keep the quoted args together for when
154            # the QEMU command is issued later.
155            args = shlex.split(qemu_args)
156            self._config['extra_args'] = []
157            for arg in args:
158                if arg:
159                    # Preserve quotes around arguments.
160                    # shlex above takes them out, so add them in.
161                    if " " in arg:
162                        arg = '"{}"'.format(arg)
163                    self._config['extra_args'].append(arg)
164
165    def validate_ssh_keys(self):
166        """Check to see if the ssh key files exist."""
167        if 'ssh_key_file' not in self._config or\
168           not os.path.exists(self._config['ssh_key_file']):
169            raise Exception("ssh key file not found.")
170        if 'ssh_pub_key_file' not in self._config or\
171           not os.path.exists(self._config['ssh_pub_key_file']):
172               raise Exception("ssh pub key file not found.")
173
174    def wait_boot(self, wait_string=None):
175        """Wait for the standard string we expect
176           on completion of a normal boot.
177           The user can also choose to override with an
178           alternate string to wait for."""
179        if wait_string is None:
180            if self.login_prompt is None:
181                raise Exception("self.login_prompt not defined")
182            wait_string = self.login_prompt
183        # Intentionally bump up the default timeout under TCG,
184        # since the console wait below takes longer.
185        timeout = self.socket_timeout
186        if not kvm_available(self.arch):
187            timeout *= 8
188        self.console_init(timeout=timeout)
189        self.console_wait(wait_string)
190
191    def _download_with_cache(self, url, sha256sum=None, sha512sum=None):
192        def check_sha256sum(fname):
193            if not sha256sum:
194                return True
195            checksum = subprocess.check_output(["sha256sum", fname]).split()[0]
196            return sha256sum == checksum.decode("utf-8")
197
198        def check_sha512sum(fname):
199            if not sha512sum:
200                return True
201            checksum = subprocess.check_output(["sha512sum", fname]).split()[0]
202            return sha512sum == checksum.decode("utf-8")
203
204        cache_dir = os.path.expanduser("~/.cache/qemu-vm/download")
205        if not os.path.exists(cache_dir):
206            os.makedirs(cache_dir)
207        fname = os.path.join(cache_dir,
208                             hashlib.sha1(url.encode("utf-8")).hexdigest())
209        if os.path.exists(fname) and check_sha256sum(fname) and check_sha512sum(fname):
210            return fname
211        logging.debug("Downloading %s to %s...", url, fname)
212        subprocess.check_call(["wget", "-c", url, "-O", fname + ".download"],
213                              stdout=self._stdout, stderr=self._stderr)
214        os.rename(fname + ".download", fname)
215        return fname
216
217    def _ssh_do(self, user, cmd, check):
218        ssh_cmd = ["ssh",
219                   "-t",
220                   "-o", "StrictHostKeyChecking=no",
221                   "-o", "UserKnownHostsFile=" + os.devnull,
222                   "-o",
223                   "ConnectTimeout={}".format(self._config["ssh_timeout"]),
224                   "-p", self.ssh_port, "-i", self._ssh_tmp_key_file]
225        # If not in debug mode, set ssh to quiet mode to
226        # avoid printing the results of commands.
227        if not self.debug:
228            ssh_cmd.append("-q")
229        for var in self.envvars:
230            ssh_cmd += ['-o', "SendEnv=%s" % var ]
231        assert not isinstance(cmd, str)
232        ssh_cmd += ["%s@127.0.0.1" % user] + list(cmd)
233        logging.debug("ssh_cmd: %s", " ".join(ssh_cmd))
234        r = subprocess.call(ssh_cmd)
235        if check and r != 0:
236            raise Exception("SSH command failed: %s" % cmd)
237        return r
238
239    def ssh(self, *cmd):
240        return self._ssh_do(self._config["guest_user"], cmd, False)
241
242    def ssh_root(self, *cmd):
243        return self._ssh_do("root", cmd, False)
244
245    def ssh_check(self, *cmd):
246        self._ssh_do(self._config["guest_user"], cmd, True)
247
248    def ssh_root_check(self, *cmd):
249        self._ssh_do("root", cmd, True)
250
251    def build_image(self, img):
252        raise NotImplementedError
253
254    def exec_qemu_img(self, *args):
255        cmd = [os.environ.get("QEMU_IMG", "qemu-img")]
256        cmd.extend(list(args))
257        subprocess.check_call(cmd)
258
259    def add_source_dir(self, src_dir):
260        name = "data-" + hashlib.sha1(src_dir.encode("utf-8")).hexdigest()[:5]
261        tarfile = os.path.join(self._tmpdir, name + ".tar")
262        logging.debug("Creating archive %s for src_dir dir: %s", tarfile, src_dir)
263        subprocess.check_call(["./scripts/archive-source.sh", tarfile],
264                              cwd=src_dir, stdin=self._devnull,
265                              stdout=self._stdout, stderr=self._stderr)
266        self._data_args += ["-drive",
267                            "file=%s,if=none,id=%s,cache=writeback,format=raw" % \
268                                    (tarfile, name),
269                            "-device",
270                            "virtio-blk,drive=%s,serial=%s,bootindex=1" % (name, name)]
271
272    def boot(self, img, extra_args=[]):
273        boot_dev = BOOT_DEVICE[self._config['boot_dev_type']]
274        boot_params = boot_dev.format(img)
275        args = self._args + boot_params.split(' ')
276        args += self._data_args + extra_args + self._config['extra_args']
277        logging.debug("QEMU args: %s", " ".join(args))
278        qemu_path = get_qemu_path(self.arch, self._build_path)
279
280        # Since console_log_path is only set when the user provides the
281        # log_console option, we will set drain_console=True so the
282        # console is always drained.
283        guest = QEMUMachine(binary=qemu_path, args=args,
284                            console_log=self._console_log_path,
285                            drain_console=True)
286        guest.set_machine(self._config['machine'])
287        guest.set_console()
288        try:
289            guest.launch()
290        except:
291            logging.error("Failed to launch QEMU, command line:")
292            logging.error(" ".join([qemu_path] + args))
293            logging.error("Log:")
294            logging.error(guest.get_log())
295            logging.error("QEMU version >= 2.10 is required")
296            raise
297        atexit.register(self.shutdown)
298        self._guest = guest
299        # Init console so we can start consuming the chars.
300        self.console_init()
301        usernet_info = guest.qmp("human-monitor-command",
302                                 command_line="info usernet")
303        self.ssh_port = None
304        for l in usernet_info["return"].splitlines():
305            fields = l.split()
306            if "TCP[HOST_FORWARD]" in fields and "22" in fields:
307                self.ssh_port = l.split()[3]
308        if not self.ssh_port:
309            raise Exception("Cannot find ssh port from 'info usernet':\n%s" % \
310                            usernet_info)
311
312    def console_init(self, timeout = None):
313        if timeout == None:
314            timeout = self.socket_timeout
315        vm = self._guest
316        vm.console_socket.settimeout(timeout)
317        self.console_raw_path = os.path.join(vm._temp_dir,
318                                             vm._name + "-console.raw")
319        self.console_raw_file = open(self.console_raw_path, 'wb')
320
321    def console_log(self, text):
322        for line in re.split("[\r\n]", text):
323            # filter out terminal escape sequences
324            line = re.sub("\x1b\[[0-9;?]*[a-zA-Z]", "", line)
325            line = re.sub("\x1b\([0-9;?]*[a-zA-Z]", "", line)
326            # replace unprintable chars
327            line = re.sub("\x1b", "<esc>", line)
328            line = re.sub("[\x00-\x1f]", ".", line)
329            line = re.sub("[\x80-\xff]", ".", line)
330            if line == "":
331                continue
332            # log console line
333            sys.stderr.write("con recv: %s\n" % line)
334
335    def console_wait(self, expect, expectalt = None):
336        vm = self._guest
337        output = ""
338        while True:
339            try:
340                chars = vm.console_socket.recv(1)
341                if self.console_raw_file:
342                    self.console_raw_file.write(chars)
343                    self.console_raw_file.flush()
344            except socket.timeout:
345                sys.stderr.write("console: *** read timeout ***\n")
346                sys.stderr.write("console: waiting for: '%s'\n" % expect)
347                if not expectalt is None:
348                    sys.stderr.write("console: waiting for: '%s' (alt)\n" % expectalt)
349                sys.stderr.write("console: line buffer:\n")
350                sys.stderr.write("\n")
351                self.console_log(output.rstrip())
352                sys.stderr.write("\n")
353                raise
354            output += chars.decode("latin1")
355            if expect in output:
356                break
357            if not expectalt is None and expectalt in output:
358                break
359            if "\r" in output or "\n" in output:
360                lines = re.split("[\r\n]", output)
361                output = lines.pop()
362                if self.debug:
363                    self.console_log("\n".join(lines))
364        if self.debug:
365            self.console_log(output)
366        if not expectalt is None and expectalt in output:
367            return False
368        return True
369
370    def console_consume(self):
371        vm = self._guest
372        output = ""
373        vm.console_socket.setblocking(0)
374        while True:
375            try:
376                chars = vm.console_socket.recv(1)
377            except:
378                break
379            output += chars.decode("latin1")
380            if "\r" in output or "\n" in output:
381                lines = re.split("[\r\n]", output)
382                output = lines.pop()
383                if self.debug:
384                    self.console_log("\n".join(lines))
385        if self.debug:
386            self.console_log(output)
387        vm.console_socket.setblocking(1)
388
389    def console_send(self, command):
390        vm = self._guest
391        if self.debug:
392            logline = re.sub("\n", "<enter>", command)
393            logline = re.sub("[\x00-\x1f]", ".", logline)
394            sys.stderr.write("con send: %s\n" % logline)
395        for char in list(command):
396            vm.console_socket.send(char.encode("utf-8"))
397            time.sleep(0.01)
398
399    def console_wait_send(self, wait, command):
400        self.console_wait(wait)
401        self.console_send(command)
402
403    def console_ssh_init(self, prompt, user, pw):
404        sshkey_cmd = "echo '%s' > .ssh/authorized_keys\n" \
405                     % self._config['ssh_pub_key'].rstrip()
406        self.console_wait_send("login:",    "%s\n" % user)
407        self.console_wait_send("Password:", "%s\n" % pw)
408        self.console_wait_send(prompt,      "mkdir .ssh\n")
409        self.console_wait_send(prompt,      sshkey_cmd)
410        self.console_wait_send(prompt,      "chmod 755 .ssh\n")
411        self.console_wait_send(prompt,      "chmod 644 .ssh/authorized_keys\n")
412
413    def console_sshd_config(self, prompt):
414        self.console_wait(prompt)
415        self.console_send("echo 'PermitRootLogin yes' >> /etc/ssh/sshd_config\n")
416        for var in self.envvars:
417            self.console_wait(prompt)
418            self.console_send("echo 'AcceptEnv %s' >> /etc/ssh/sshd_config\n" % var)
419
420    def print_step(self, text):
421        sys.stderr.write("### %s ...\n" % text)
422
423    def wait_ssh(self, wait_root=False, seconds=300, cmd="exit 0"):
424        # Allow more time for VM to boot under TCG.
425        if not kvm_available(self.arch):
426            seconds *= self.tcg_ssh_timeout_multiplier
427        starttime = datetime.datetime.now()
428        endtime = starttime + datetime.timedelta(seconds=seconds)
429        cmd_success = False
430        while datetime.datetime.now() < endtime:
431            if wait_root and self.ssh_root(cmd) == 0:
432                cmd_success = True
433                break
434            elif self.ssh(cmd) == 0:
435                cmd_success = True
436                break
437            seconds = (endtime - datetime.datetime.now()).total_seconds()
438            logging.debug("%ds before timeout", seconds)
439            time.sleep(1)
440        if not cmd_success:
441            raise Exception("Timeout while waiting for guest ssh")
442
443    def shutdown(self):
444        self._guest.shutdown()
445
446    def wait(self):
447        self._guest.wait()
448
449    def graceful_shutdown(self):
450        self.ssh_root(self.poweroff)
451        self._guest.wait()
452
453    def qmp(self, *args, **kwargs):
454        return self._guest.qmp(*args, **kwargs)
455
456    def gen_cloud_init_iso(self):
457        cidir = self._tmpdir
458        mdata = open(os.path.join(cidir, "meta-data"), "w")
459        name = self.name.replace(".","-")
460        mdata.writelines(["instance-id: {}-vm-0\n".format(name),
461                          "local-hostname: {}-guest\n".format(name)])
462        mdata.close()
463        udata = open(os.path.join(cidir, "user-data"), "w")
464        print("guest user:pw {}:{}".format(self._config['guest_user'],
465                                           self._config['guest_pass']))
466        udata.writelines(["#cloud-config\n",
467                          "chpasswd:\n",
468                          "  list: |\n",
469                          "    root:%s\n" % self._config['root_pass'],
470                          "    %s:%s\n" % (self._config['guest_user'],
471                                           self._config['guest_pass']),
472                          "  expire: False\n",
473                          "users:\n",
474                          "  - name: %s\n" % self._config['guest_user'],
475                          "    sudo: ALL=(ALL) NOPASSWD:ALL\n",
476                          "    ssh-authorized-keys:\n",
477                          "    - %s\n" % self._config['ssh_pub_key'],
478                          "  - name: root\n",
479                          "    ssh-authorized-keys:\n",
480                          "    - %s\n" % self._config['ssh_pub_key'],
481                          "locale: en_US.UTF-8\n"])
482        proxy = os.environ.get("http_proxy")
483        if not proxy is None:
484            udata.writelines(["apt:\n",
485                              "  proxy: %s" % proxy])
486        udata.close()
487        subprocess.check_call([self._genisoimage, "-output", "cloud-init.iso",
488                               "-volid", "cidata", "-joliet", "-rock",
489                               "user-data", "meta-data"],
490                              cwd=cidir,
491                              stdin=self._devnull, stdout=self._stdout,
492                              stderr=self._stdout)
493        return os.path.join(cidir, "cloud-init.iso")
494
495def get_qemu_path(arch, build_path=None):
496    """Fetch the path to the qemu binary."""
497    # If QEMU environment variable set, it takes precedence
498    if "QEMU" in os.environ:
499        qemu_path = os.environ["QEMU"]
500    elif build_path:
501        qemu_path = os.path.join(build_path, arch + "-softmmu")
502        qemu_path = os.path.join(qemu_path, "qemu-system-" + arch)
503    else:
504        # Default is to use system path for qemu.
505        qemu_path = "qemu-system-" + arch
506    return qemu_path
507
508def get_qemu_version(qemu_path):
509    """Get the version number from the current QEMU,
510       and return the major number."""
511    output = subprocess.check_output([qemu_path, '--version'])
512    version_line = output.decode("utf-8")
513    version_num = re.split(' |\(', version_line)[3].split('.')[0]
514    return int(version_num)
515
516def parse_config(config, args):
517    """ Parse yaml config and populate our config structure.
518        The yaml config allows the user to override the
519        defaults for VM parameters.  In many cases these
520        defaults can be overridden without rebuilding the VM."""
521    if args.config:
522        config_file = args.config
523    elif 'QEMU_CONFIG' in os.environ:
524        config_file = os.environ['QEMU_CONFIG']
525    else:
526        return config
527    if not os.path.exists(config_file):
528        raise Exception("config file {} does not exist".format(config_file))
529    # We gracefully handle importing the yaml module
530    # since it might not be installed.
531    # If we are here it means the user supplied a .yml file,
532    # so if the yaml module is not installed we will exit with error.
533    try:
534        import yaml
535    except ImportError:
536        print("The python3-yaml package is needed "\
537              "to support config.yaml files")
538        # Instead of raising an exception we exit to avoid
539        # a raft of messy (expected) errors to stdout.
540        exit(1)
541    with open(config_file) as f:
542        yaml_dict = yaml.safe_load(f)
543
544    if 'qemu-conf' in yaml_dict:
545        config.update(yaml_dict['qemu-conf'])
546    else:
547        raise Exception("config file {} is not valid"\
548                        " missing qemu-conf".format(config_file))
549    return config
550
551def parse_args(vmcls):
552
553    def get_default_jobs():
554        if multiprocessing.cpu_count() > 1:
555            if kvm_available(vmcls.arch):
556                return multiprocessing.cpu_count() // 2
557            elif os.uname().machine == "x86_64" and \
558                 vmcls.arch in ["aarch64", "x86_64", "i386"]:
559                # MTTCG is available on these arches and we can allow
560                # more cores. but only up to a reasonable limit. User
561                # can always override these limits with --jobs.
562                return min(multiprocessing.cpu_count() // 2, 8)
563        else:
564            return 1
565
566    parser = argparse.ArgumentParser(
567        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
568        description="Utility for provisioning VMs and running builds",
569        epilog="""Remaining arguments are passed to the command.
570        Exit codes: 0 = success, 1 = command line error,
571        2 = environment initialization failed,
572        3 = test command failed""")
573    parser.add_argument("--debug", "-D", action="store_true",
574                        help="enable debug output")
575    parser.add_argument("--image", "-i", default="%s.img" % vmcls.name,
576                        help="image file name")
577    parser.add_argument("--force", "-f", action="store_true",
578                        help="force build image even if image exists")
579    parser.add_argument("--jobs", type=int, default=get_default_jobs(),
580                        help="number of virtual CPUs")
581    parser.add_argument("--verbose", "-V", action="store_true",
582                        help="Pass V=1 to builds within the guest")
583    parser.add_argument("--build-image", "-b", action="store_true",
584                        help="build image")
585    parser.add_argument("--build-qemu",
586                        help="build QEMU from source in guest")
587    parser.add_argument("--build-target",
588                        help="QEMU build target", default="check")
589    parser.add_argument("--build-path", default=None,
590                        help="Path of build directory, "\
591                        "for using build tree QEMU binary. ")
592    parser.add_argument("--interactive", "-I", action="store_true",
593                        help="Interactively run command")
594    parser.add_argument("--snapshot", "-s", action="store_true",
595                        help="run tests with a snapshot")
596    parser.add_argument("--genisoimage", default="genisoimage",
597                        help="iso imaging tool")
598    parser.add_argument("--config", "-c", default=None,
599                        help="Provide config yaml for configuration. "\
600                        "See config_example.yaml for example.")
601    parser.add_argument("--efi-aarch64",
602                        default="/usr/share/qemu-efi-aarch64/QEMU_EFI.fd",
603                        help="Path to efi image for aarch64 VMs.")
604    parser.add_argument("--log-console", action="store_true",
605                        help="Log console to file.")
606    parser.add_argument("commands", nargs="*", help="""Remaining
607        commands after -- are passed to command inside the VM""")
608
609    return parser.parse_args()
610
611def main(vmcls, config=None):
612    try:
613        if config == None:
614            config = DEFAULT_CONFIG
615        args = parse_args(vmcls)
616        if not args.commands and not args.build_qemu and not args.build_image:
617            print("Nothing to do?")
618            return 1
619        config = parse_config(config, args)
620        logging.basicConfig(level=(logging.DEBUG if args.debug
621                                   else logging.WARN))
622        vm = vmcls(args, config=config)
623        if args.build_image:
624            if os.path.exists(args.image) and not args.force:
625                sys.stderr.writelines(["Image file exists: %s\n" % args.image,
626                                      "Use --force option to overwrite\n"])
627                return 1
628            return vm.build_image(args.image)
629        if args.build_qemu:
630            vm.add_source_dir(args.build_qemu)
631            cmd = [vm.BUILD_SCRIPT.format(
632                   configure_opts = " ".join(args.commands),
633                   jobs=int(args.jobs),
634                   target=args.build_target,
635                   verbose = "V=1" if args.verbose else "")]
636        else:
637            cmd = args.commands
638        img = args.image
639        if args.snapshot:
640            img += ",snapshot=on"
641        vm.boot(img)
642        vm.wait_ssh()
643    except Exception as e:
644        if isinstance(e, SystemExit) and e.code == 0:
645            return 0
646        sys.stderr.write("Failed to prepare guest environment\n")
647        traceback.print_exc()
648        return 2
649
650    exitcode = 0
651    if vm.ssh(*cmd) != 0:
652        exitcode = 3
653    if args.interactive:
654        vm.ssh()
655
656    if not args.snapshot:
657        vm.graceful_shutdown()
658
659    return exitcode
660