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1# Copyright 2015 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5import collections
6import json
7import logging
8import os
9import re
10import tempfile
11import time
12
13import common
14from autotest_lib.client.bin import utils
15from autotest_lib.client.common_lib import error
16from autotest_lib.site_utils.lxc import constants
17from autotest_lib.site_utils.lxc import lxc
18from autotest_lib.site_utils.lxc import utils as lxc_utils
19
20try:
21    from chromite.lib import metrics
22except ImportError:
23    metrics = utils.metrics_mock
24
25ISOLATESERVER = 'https://isolateserver.appspot.com'
26
27# Naming convention of test container, e.g., test_300_1422862512_2424, where:
28# 300:        The test job ID.
29# 1422862512: The tick when container is created.
30# 2424:       The PID of autoserv that starts the container.
31_TEST_CONTAINER_NAME_FMT = 'test_%s_%d_%d'
32# Name of the container ID file.
33_CONTAINER_ID_FILENAME = 'container_id.json'
34
35
36class ContainerId(collections.namedtuple('ContainerId',
37                                         ['job_id', 'creation_time', 'pid'])):
38    """An identifier for containers."""
39
40    # Optimization.  Avoids __dict__ creation.  Empty because this subclass has
41    # no instance vars of its own.
42    __slots__ = ()
43
44
45    def __str__(self):
46        return _TEST_CONTAINER_NAME_FMT % self
47
48
49    def save(self, path):
50        """Saves the ID to the given path.
51
52        @param path: Path to a directory where the container ID will be
53                     serialized.
54        """
55        dst = os.path.join(path, _CONTAINER_ID_FILENAME)
56        with open(dst, 'w') as f:
57            json.dump(self, f)
58
59    @classmethod
60    def load(cls, path):
61        """Reads the ID from the given path.
62
63        @param path: Path to check for a serialized container ID.
64
65        @return: A container ID if one is found on the given path, or None
66                 otherwise.
67
68        @raise ValueError: If a JSON load error occurred.
69        @raise TypeError: If the file was valid JSON but didn't contain a valid
70                          ContainerId.
71        """
72        src = os.path.join(path, _CONTAINER_ID_FILENAME)
73
74        try:
75            with open(src, 'r') as f:
76                job_id, ctime, pid = json.load(f)
77        except IOError:
78            # File not found, or couldn't be opened for some other reason.
79            # Treat all these cases as no ID.
80            return None
81        # TODO(pprabhu, crbug.com/842343) Remove this once all persistent
82        # container ids have migrated to str.
83        job_id = str(job_id)
84        return cls(job_id, ctime, pid)
85
86
87    @classmethod
88    def create(cls, job_id, ctime=None, pid=None):
89        """Creates a new container ID.
90
91        @param job_id: The first field in the ID.
92        @param ctime: The second field in the ID.  Optional. If not provided,
93                      the current epoch timestamp is used.
94        @param pid: The third field in the ID.  Optional.  If not provided, the
95                    PID of the current process is used.
96        """
97        if ctime is None:
98            ctime = int(time.time())
99        if pid is None:
100            pid = os.getpid()
101        # TODO(pprabhu) Drop str() cast once
102        # job_directories.get_job_id_or_task_id() starts returning str directly.
103        return cls(str(job_id), ctime, pid)
104
105
106class Container(object):
107    """A wrapper class of an LXC container.
108
109    The wrapper class provides methods to interact with a container, e.g.,
110    start, stop, destroy, run a command. It also has attributes of the
111    container, including:
112    name: Name of the container.
113    state: State of the container, e.g., ABORTING, RUNNING, STARTING, STOPPED,
114           or STOPPING.
115
116    lxc-ls can also collect other attributes of a container including:
117    ipv4: IP address for IPv4.
118    ipv6: IP address for IPv6.
119    autostart: If the container will autostart at system boot.
120    pid: Process ID of the container.
121    memory: Memory used by the container, as a string, e.g., "6.2MB"
122    ram: Physical ram used by the container, as a string, e.g., "6.2MB"
123    swap: swap used by the container, as a string, e.g., "1.0MB"
124
125    For performance reason, such info is not collected for now.
126
127    The attributes available are defined in ATTRIBUTES constant.
128    """
129
130    _LXC_VERSION = None
131
132    def __init__(self, container_path, name, attribute_values, src=None,
133                 snapshot=False):
134        """Initialize an object of LXC container with given attribute values.
135
136        @param container_path: Directory that stores the container.
137        @param name: Name of the container.
138        @param attribute_values: A dictionary of attribute values for the
139                                 container.
140        @param src: An optional source container.  If provided, the source
141                    continer is cloned, and the new container will point to the
142                    clone.
143        @param snapshot: If a source container was specified, this argument
144                         specifies whether or not to create a snapshot clone.
145                         The default is to attempt to create a snapshot.
146                         If a snapshot is requested and creating the snapshot
147                         fails, a full clone will be attempted.
148        """
149        self.container_path = os.path.realpath(container_path)
150        # Path to the rootfs of the container. This will be initialized when
151        # property rootfs is retrieved.
152        self._rootfs = None
153        self.name = name
154        for attribute, value in attribute_values.iteritems():
155            setattr(self, attribute, value)
156
157        # Clone the container
158        if src is not None:
159            # Clone the source container to initialize this one.
160            lxc_utils.clone(src.container_path, src.name, self.container_path,
161                            self.name, snapshot)
162            # Newly cloned containers have no ID.
163            self._id = None
164        else:
165            # This may be an existing container.  Try to read the ID.
166            try:
167                self._id = ContainerId.load(
168                        os.path.join(self.container_path, self.name))
169            except (ValueError, TypeError):
170                # Ignore load errors.  ContainerBucket currently queries every
171                # container quite frequently, and emitting exceptions here would
172                # cause any invalid containers on a server to block all
173                # ContainerBucket.get_all calls (see crbug/783865).
174                logging.warning('Unable to determine ID for container %s:',
175                                self.name)
176                self._id = None
177
178        if not Container._LXC_VERSION:
179          Container._LXC_VERSION = lxc_utils.get_lxc_version()
180
181
182    @classmethod
183    def create_from_existing_dir(cls, lxc_path, name, **kwargs):
184        """Creates a new container instance for an lxc container that already
185        exists on disk.
186
187        @param lxc_path: The LXC path for the container.
188        @param name: The container name.
189
190        @raise error.ContainerError: If the container doesn't already exist.
191
192        @return: The new container.
193        """
194        return cls(lxc_path, name, kwargs)
195
196
197    # Containers have a name and an ID.  The name is simply the name of the LXC
198    # container.  The ID is the actual key that is used to identify the
199    # container to the autoserv system.  In the case of a JIT-created container,
200    # we have the ID at the container's creation time so we use that to name the
201    # container.  This may not be the case for other types of containers.
202    @classmethod
203    def clone(cls, src, new_name=None, new_path=None, snapshot=False,
204              cleanup=False):
205        """Creates a clone of this container.
206
207        @param src: The original container.
208        @param new_name: Name for the cloned container.  If this is not
209                         provided, a random unique container name will be
210                         generated.
211        @param new_path: LXC path for the cloned container (optional; if not
212                         specified, the new container is created in the same
213                         directory as the source container).
214        @param snapshot: Whether to snapshot, or create a full clone.  Note that
215                         snapshot cloning is not supported on all platforms.  If
216                         this code is running on a platform that does not
217                         support snapshot clones, this flag is ignored.
218        @param cleanup: If a container with the given name and path already
219                        exist, clean it up first.
220        """
221        if new_path is None:
222            new_path = src.container_path
223
224        if new_name is None:
225            _, new_name = os.path.split(
226                tempfile.mkdtemp(dir=new_path, prefix='container.'))
227            logging.debug('Generating new name for container: %s', new_name)
228        else:
229            # If a container exists at this location, clean it up first
230            container_folder = os.path.join(new_path, new_name)
231            if lxc_utils.path_exists(container_folder):
232                if not cleanup:
233                    raise error.ContainerError('Container %s already exists.' %
234                                               new_name)
235                container = Container.create_from_existing_dir(new_path,
236                                                               new_name)
237                try:
238                    container.destroy()
239                except error.CmdError as e:
240                    # The container could be created in a incompleted
241                    # state. Delete the container folder instead.
242                    logging.warn('Failed to destroy container %s, error: %s',
243                                 new_name, e)
244                    utils.run('sudo rm -rf "%s"' % container_folder)
245            # Create the directory prior to creating the new container.  This
246            # puts the ownership of the container under the current process's
247            # user, rather than root.  This is necessary to enable the
248            # ContainerId to serialize properly.
249            os.mkdir(container_folder)
250
251        # Create and return the new container.
252        new_container = cls(new_path, new_name, {}, src, snapshot)
253
254        return new_container
255
256
257    def refresh_status(self):
258        """Refresh the status information of the container.
259        """
260        containers = lxc.get_container_info(self.container_path, name=self.name)
261        if not containers:
262            raise error.ContainerError(
263                    'No container found in directory %s with name of %s.' %
264                    (self.container_path, self.name))
265        attribute_values = containers[0]
266        for attribute, value in attribute_values.iteritems():
267            setattr(self, attribute, value)
268
269
270    @property
271    def rootfs(self):
272        """Path to the rootfs of the container.
273
274        This property returns the path to the rootfs of the container, that is,
275        the folder where the container stores its local files. It reads the
276        attribute lxc.rootfs from the config file of the container, e.g.,
277            lxc.rootfs = /usr/local/autotest/containers/t4/rootfs
278        If the container is created with snapshot, the rootfs is a chain of
279        folders, separated by `:` and ordered by how the snapshot is created,
280        e.g.,
281            lxc.rootfs = overlayfs:/usr/local/autotest/containers/base/rootfs:
282            /usr/local/autotest/containers/t4_s/delta0
283        This function returns the last folder in the chain, in above example,
284        that is `/usr/local/autotest/containers/t4_s/delta0`
285
286        Files in the rootfs will be accessible directly within container. For
287        example, a folder in host "[rootfs]/usr/local/file1", can be accessed
288        inside container by path "/usr/local/file1". Note that symlink in the
289        host can not across host/container boundary, instead, directory mount
290        should be used, refer to function mount_dir.
291
292        @return: Path to the rootfs of the container.
293        """
294        lxc_rootfs_config_name = 'lxc.rootfs'
295        # Check to see if the major lxc version is 3 or greater
296        if Container._LXC_VERSION:
297            logging.info("Detected lxc version %s", Container._LXC_VERSION)
298            if Container._LXC_VERSION[0] >= 3:
299                lxc_rootfs_config_name = 'lxc.rootfs.path'
300        if not self._rootfs:
301            lxc_rootfs = self._get_lxc_config(lxc_rootfs_config_name)[0]
302            cloned_from_snapshot = ':' in lxc_rootfs
303            if cloned_from_snapshot:
304                self._rootfs = lxc_rootfs.split(':')[-1]
305            else:
306                self._rootfs = lxc_rootfs
307        return self._rootfs
308
309
310    def attach_run(self, command, bash=True):
311        """Attach to a given container and run the given command.
312
313        @param command: Command to run in the container.
314        @param bash: Run the command through bash -c "command". This allows
315                     pipes to be used in command. Default is set to True.
316
317        @return: The output of the command.
318
319        @raise error.CmdError: If container does not exist, or not running.
320        """
321        cmd = 'sudo lxc-attach -P %s -n %s' % (self.container_path, self.name)
322        if bash and not command.startswith('bash -c'):
323            command = 'bash -c "%s"' % utils.sh_escape(command)
324        cmd += ' -- %s' % command
325        # TODO(dshi): crbug.com/459344 Set sudo to default to False when test
326        # container can be unprivileged container.
327        return utils.run(cmd)
328
329
330    def is_network_up(self):
331        """Check if network is up in the container by curl base container url.
332
333        @return: True if the network is up, otherwise False.
334        """
335        try:
336            self.attach_run('curl --head %s' % constants.CONTAINER_BASE_URL)
337            return True
338        except error.CmdError as e:
339            logging.debug(e)
340            return False
341
342
343    @metrics.SecondsTimerDecorator(
344        '%s/container_start_duration' % constants.STATS_KEY)
345    def start(self, wait_for_network=True):
346        """Start the container.
347
348        @param wait_for_network: True to wait for network to be up. Default is
349                                 set to True.
350
351        @raise ContainerError: If container does not exist, or fails to start.
352        """
353        cmd = 'sudo lxc-start -P %s -n %s -d' % (self.container_path, self.name)
354        output = utils.run(cmd).stdout
355        if not self.is_running():
356            raise error.ContainerError(
357                    'Container %s failed to start. lxc command output:\n%s' %
358                    (os.path.join(self.container_path, self.name),
359                     output))
360
361        if wait_for_network:
362            logging.debug('Wait for network to be up.')
363            start_time = time.time()
364            utils.poll_for_condition(
365                condition=self.is_network_up,
366                timeout=constants.NETWORK_INIT_TIMEOUT,
367                sleep_interval=constants.NETWORK_INIT_CHECK_INTERVAL,
368                desc='network is up')
369            logging.debug('Network is up after %.2f seconds.',
370                          time.time() - start_time)
371
372
373    @metrics.SecondsTimerDecorator(
374        '%s/container_stop_duration' % constants.STATS_KEY)
375    def stop(self):
376        """Stop the container.
377
378        @raise ContainerError: If container does not exist, or fails to start.
379        """
380        cmd = 'sudo lxc-stop -P %s -n %s' % (self.container_path, self.name)
381        output = utils.run(cmd).stdout
382        self.refresh_status()
383        if self.state != 'STOPPED':
384            raise error.ContainerError(
385                    'Container %s failed to be stopped. lxc command output:\n'
386                    '%s' % (os.path.join(self.container_path, self.name),
387                            output))
388
389
390    @metrics.SecondsTimerDecorator(
391        '%s/container_destroy_duration' % constants.STATS_KEY)
392    def destroy(self, force=True):
393        """Destroy the container.
394
395        @param force: Set to True to force to destroy the container even if it's
396                      running. This is faster than stop a container first then
397                      try to destroy it. Default is set to True.
398
399        @raise ContainerError: If container does not exist or failed to destroy
400                               the container.
401        """
402        logging.debug('Destroying container %s/%s',
403                      self.container_path,
404                      self.name)
405        lxc_utils.destroy(self.container_path, self.name, force=force)
406
407
408    def mount_dir(self, source, destination, readonly=False):
409        """Mount a directory in host to a directory in the container.
410
411        @param source: Directory in host to be mounted.
412        @param destination: Directory in container to mount the source directory
413        @param readonly: Set to True to make a readonly mount, default is False.
414        """
415        # Destination path in container must be relative.
416        destination = destination.lstrip('/')
417        # Create directory in container for mount.  Changes to container rootfs
418        # require sudo.
419        utils.run('sudo mkdir -p %s' % os.path.join(self.rootfs, destination))
420        mount = ('%s %s none bind%s 0 0' %
421                 (source, destination, ',ro' if readonly else ''))
422        self._set_lxc_config('lxc.mount.entry', mount)
423
424    def verify_autotest_setup(self, job_folder):
425        """Verify autotest code is set up properly in the container.
426
427        @param job_folder: Name of the job result folder.
428
429        @raise ContainerError: If autotest code is not set up properly.
430        """
431        # Test autotest code is setup by verifying a list of
432        # (directory, minimum file count)
433        directories_to_check = [
434                (constants.CONTAINER_AUTOTEST_DIR, 3),
435                (constants.RESULT_DIR_FMT % job_folder, 0),
436                (constants.CONTAINER_SITE_PACKAGES_PATH, 3)]
437        for directory, count in directories_to_check:
438            result = self.attach_run(command=(constants.COUNT_FILE_CMD %
439                                              {'dir': directory})).stdout
440            logging.debug('%s entries in %s.', int(result), directory)
441            if int(result) < count:
442                raise error.ContainerError('%s is not properly set up.' %
443                                           directory)
444        # lxc-attach and run command does not run in shell, thus .bashrc is not
445        # loaded. Following command creates a symlink in /usr/bin/ for gsutil
446        # if it's installed.
447        # TODO(dshi): Remove this code after lab container is updated with
448        # gsutil installed in /usr/bin/
449        self.attach_run('test -f /root/gsutil/gsutil && '
450                        'ln -s /root/gsutil/gsutil /usr/bin/gsutil || true')
451
452
453    def modify_import_order(self):
454        """Swap the python import order of lib and local/lib.
455
456        In Moblab, the host's python modules located in
457        /usr/lib64/python2.7/site-packages is mounted to following folder inside
458        container: /usr/local/lib/python2.7/dist-packages/. The modules include
459        an old version of requests module, which is used in autotest
460        site-packages. For test, the module is only used in
461        dev_server/symbolicate_dump for requests.call and requests.codes.OK.
462        When pip is installed inside the container, it installs requests module
463        with version of 2.2.1 in /usr/lib/python2.7/dist-packages/. The version
464        is newer than the one used in autotest site-packages, but not the latest
465        either.
466        According to /usr/lib/python2.7/site.py, modules in /usr/local/lib are
467        imported before the ones in /usr/lib. That leads to pip to use the older
468        version of requests (0.11.2), and it will fail. On the other hand,
469        requests module 2.2.1 can't be installed in CrOS (refer to CL:265759),
470        and higher version of requests module can't work with pip.
471        The only fix to resolve this is to switch the import order, so modules
472        in /usr/lib can be imported before /usr/local/lib.
473        """
474        site_module = '/usr/lib/python2.7/site.py'
475        self.attach_run("sed -i ':a;N;$!ba;s/\"local\/lib\",\\n/"
476                        "\"lib_placeholder\",\\n/g' %s" % site_module)
477        self.attach_run("sed -i ':a;N;$!ba;s/\"lib\",\\n/"
478                        "\"local\/lib\",\\n/g' %s" % site_module)
479        self.attach_run('sed -i "s/lib_placeholder/lib/g" %s' %
480                        site_module)
481
482
483    def is_running(self):
484        """Returns whether or not this container is currently running."""
485        self.refresh_status()
486        return self.state == 'RUNNING'
487
488
489    def set_hostname(self, hostname):
490        """Sets the hostname within the container.
491
492        This method can only be called on a running container.
493
494        @param hostname The new container hostname.
495
496        @raise ContainerError: If the container is not running.
497        """
498        if not self.is_running():
499            raise error.ContainerError(
500                    'set_hostname can only be called on running containers.')
501
502        self.attach_run('hostname %s' % (hostname))
503        self.attach_run(constants.APPEND_CMD_FMT % {
504                'content': '127.0.0.1 %s' % (hostname),
505                'file': '/etc/hosts'})
506
507
508    def install_ssp(self, ssp_url):
509        """Downloads and installs the given server package.
510
511        @param ssp_url: The URL of the ssp to download and install.
512        """
513        usr_local_path = os.path.join(self.rootfs, 'usr', 'local')
514        autotest_pkg_path = os.path.join(usr_local_path,
515                                         'autotest_server_package.tar.bz2')
516        # Changes within the container rootfs require sudo.
517        utils.run('sudo mkdir -p %s'% usr_local_path)
518
519        lxc.download_extract(ssp_url, autotest_pkg_path, usr_local_path)
520
521    def install_ssp_isolate(self, isolate_hash, dest_path=None):
522        """Downloads and install the contents of the given isolate.
523        This places the isolate contents under /usr/local or a provided path.
524        Most commonly this is a copy of a specific autotest version, in which
525        case:
526          /usr/local/autotest contains the autotest code
527          /usr/local/logs contains logs from the installation process.
528
529        @param isolate_hash: The hash string which serves as a key to retrieve
530                             the desired isolate
531        @param dest_path: Path to the directory to place the isolate in.
532                          Defaults to /usr/local/
533
534        @return: Exit status of the installation command.
535        """
536        dest_path = dest_path or os.path.join(self.rootfs, 'usr', 'local')
537        isolate_log_path = os.path.join(
538            self.rootfs, 'usr', 'local', 'logs', 'isolate')
539        log_file = os.path.join(isolate_log_path,
540            'contents.' + time.strftime('%Y-%m-%d-%H.%M.%S'))
541
542        utils.run('sudo mkdir -p %s' % isolate_log_path)
543        _command = ("sudo isolated download -isolated {sha} -I {server}"
544                    " -output-dir {dest_dir} -output-files {log_file}")
545
546        return utils.run(_command.format(
547            sha=isolate_hash, dest_dir=dest_path,
548            log_file=log_file, server=ISOLATESERVER))
549
550
551    def install_control_file(self, control_file):
552        """Installs the given control file.
553
554        The given file will be copied into the container.
555
556        @param control_file: Path to the control file to install.
557        """
558        dst = os.path.join(constants.CONTROL_TEMP_PATH,
559                           os.path.basename(control_file))
560        self.copy(control_file, dst)
561
562
563    def copy(self, host_path, container_path):
564        """Copies files into the container.
565
566        @param host_path: Path to the source file/dir to be copied.
567        @param container_path: Path to the destination dir (in the container).
568        """
569        dst_path = os.path.join(self.rootfs,
570                                container_path.lstrip(os.path.sep))
571        self._do_copy(src=host_path, dst=dst_path)
572
573
574    @property
575    def id(self):
576        """Returns the container ID."""
577        return self._id
578
579
580    @id.setter
581    def id(self, new_id):
582        """Sets the container ID."""
583        self._id = new_id;
584        # Persist the ID so other container objects can pick it up.
585        self._id.save(os.path.join(self.container_path, self.name))
586
587
588    def _do_copy(self, src, dst):
589        """Copies files and directories on the host system.
590
591        @param src: The source file or directory.
592        @param dst: The destination file or directory.  If the path to the
593                    destination does not exist, it will be created.
594        """
595        # Create the dst dir. mkdir -p will not fail if dst_dir exists.
596        dst_dir = os.path.dirname(dst)
597        # Make sure the source ends with `/.` if it's a directory. Otherwise
598        # command cp will not work.
599        if os.path.isdir(src) and os.path.split(src)[1] != '.':
600            src = os.path.join(src, '.')
601        utils.run("sudo sh -c 'mkdir -p \"%s\" && cp -RL \"%s\" \"%s\"'" %
602                  (dst_dir, src, dst))
603
604    def _set_lxc_config(self, key, value):
605        """Sets an LXC config value for this container.
606
607        Configuration changes made while a container is running don't take
608        effect until the container is restarted.  Since this isn't a scenario
609        that should ever come up in our use cases, calling this method on a
610        running container will cause a ContainerError.
611
612        @param key: The LXC config key to set.
613        @param value: The value to use for the given key.
614
615        @raise error.ContainerError: If the container is already started.
616        """
617        if self.is_running():
618            raise error.ContainerError(
619                '_set_lxc_config(%s, %s) called on a running container.' %
620                (key, value))
621        config_file = os.path.join(self.container_path, self.name, 'config')
622        config = '%s = %s' % (key, value)
623        utils.run(
624            constants.APPEND_CMD_FMT % {'content': config, 'file': config_file})
625
626
627    def _get_lxc_config(self, key):
628        """Retrieves an LXC config value from the container.
629
630        @param key The key of the config value to retrieve.
631        """
632        cmd = ('sudo lxc-info -P %s -n %s -c %s' %
633               (self.container_path, self.name, key))
634        config = utils.run(cmd).stdout.strip().splitlines()
635
636        # Strip the decoration from line 1 of the output.
637        match = re.match('%s = (.*)' % key, config[0])
638        if not match:
639            raise error.ContainerError(
640                    'Config %s not found for container %s. (%s)' %
641                    (key, self.name, ','.join(config)))
642        config[0] = match.group(1)
643        return config
644