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1# Copyright 2009 Google Inc. Released under the GPL v2
2
3"""
4This module defines the base classes for the Host hierarchy.
5
6Implementation details:
7You should import the "hosts" package instead of importing each type of host.
8
9        Host: a machine on which you can run programs
10"""
11
12__author__ = """
13mbligh@google.com (Martin J. Bligh),
14poirier@google.com (Benjamin Poirier),
15stutsman@google.com (Ryan Stutsman)
16"""
17
18import cPickle, logging, os, re, time
19
20from autotest_lib.client.common_lib import global_config, error, utils
21from autotest_lib.client.common_lib.cros import path_utils
22
23
24class Host(object):
25    """
26    This class represents a machine on which you can run programs.
27
28    It may be a local machine, the one autoserv is running on, a remote
29    machine or a virtual machine.
30
31    Implementation details:
32    This is an abstract class, leaf subclasses must implement the methods
33    listed here. You must not instantiate this class but should
34    instantiate one of those leaf subclasses.
35
36    When overriding methods that raise NotImplementedError, the leaf class
37    is fully responsible for the implementation and should not chain calls
38    to super. When overriding methods that are a NOP in Host, the subclass
39    should chain calls to super(). The criteria for fitting a new method into
40    one category or the other should be:
41        1. If two separate generic implementations could reasonably be
42           concatenated, then the abstract implementation should pass and
43           subclasses should chain calls to super.
44        2. If only one class could reasonably perform the stated function
45           (e.g. two separate run() implementations cannot both be executed)
46           then the method should raise NotImplementedError in Host, and
47           the implementor should NOT chain calls to super, to ensure that
48           only one implementation ever gets executed.
49    """
50
51    job = None
52    DEFAULT_REBOOT_TIMEOUT = global_config.global_config.get_config_value(
53        "HOSTS", "default_reboot_timeout", type=int, default=1800)
54    WAIT_DOWN_REBOOT_TIMEOUT = global_config.global_config.get_config_value(
55        "HOSTS", "wait_down_reboot_timeout", type=int, default=840)
56    WAIT_DOWN_REBOOT_WARNING = global_config.global_config.get_config_value(
57        "HOSTS", "wait_down_reboot_warning", type=int, default=540)
58    HOURS_TO_WAIT_FOR_RECOVERY = global_config.global_config.get_config_value(
59        "HOSTS", "hours_to_wait_for_recovery", type=float, default=2.5)
60    # the number of hardware repair requests that need to happen before we
61    # actually send machines to hardware repair
62    HARDWARE_REPAIR_REQUEST_THRESHOLD = 4
63    OP_REBOOT = 'reboot'
64    OP_SUSPEND = 'suspend'
65    PWR_OPERATION = [OP_REBOOT, OP_SUSPEND]
66
67
68    def __init__(self, *args, **dargs):
69        self._initialize(*args, **dargs)
70
71
72    def _initialize(self, *args, **dargs):
73        pass
74
75
76    @property
77    def job_repo_url_attribute(self):
78        """Get the host attribute name for job_repo_url.
79        """
80        return 'job_repo_url'
81
82
83    def close(self):
84        """Close the connection to the host.
85        """
86        pass
87
88
89    def setup(self):
90        """Setup the host object.
91        """
92        pass
93
94
95    def run(self, command, timeout=3600, ignore_status=False,
96            stdout_tee=utils.TEE_TO_LOGS, stderr_tee=utils.TEE_TO_LOGS,
97            stdin=None, args=()):
98        """
99        Run a command on this host.
100
101        @param command: the command line string
102        @param timeout: time limit in seconds before attempting to
103                kill the running process. The run() function
104                will take a few seconds longer than 'timeout'
105                to complete if it has to kill the process.
106        @param ignore_status: do not raise an exception, no matter
107                what the exit code of the command is.
108        @param stdout_tee: where to tee the stdout
109        @param stderr_tee: where to tee the stderr
110        @param stdin: stdin to pass (a string) to the executed command
111        @param args: sequence of strings to pass as arguments to command by
112                quoting them in " and escaping their contents if necessary
113
114        @return a utils.CmdResult object
115
116        @raises AutotestHostRunError: the exit code of the command execution
117                was not 0 and ignore_status was not enabled
118        """
119        raise NotImplementedError('Run not implemented!')
120
121
122    def run_output(self, command, *args, **dargs):
123        """Run and retrieve the value of stdout stripped of whitespace.
124
125        @param command: Command to execute.
126        @param *args: Extra arguments to run.
127        @param **dargs: Extra keyword arguments to run.
128
129        @return: String value of stdout.
130        """
131        return self.run(command, *args, **dargs).stdout.rstrip()
132
133
134    def reboot(self):
135        """Reboot the host.
136        """
137        raise NotImplementedError('Reboot not implemented!')
138
139
140    def suspend(self):
141        """Suspend the host.
142        """
143        raise NotImplementedError('Suspend not implemented!')
144
145
146    def sysrq_reboot(self):
147        """Execute host reboot via SysRq key.
148        """
149        raise NotImplementedError('Sysrq reboot not implemented!')
150
151
152    def reboot_setup(self, *args, **dargs):
153        """Prepare for reboot.
154
155        This doesn't appear to be implemented by any current hosts.
156
157        @param *args: Extra arguments to ?.
158        @param **dargs: Extra keyword arguments to ?.
159        """
160        pass
161
162
163    def reboot_followup(self, *args, **dargs):
164        """Post reboot work.
165
166        This doesn't appear to be implemented by any current hosts.
167
168        @param *args: Extra arguments to ?.
169        @param **dargs: Extra keyword arguments to ?.
170        """
171        pass
172
173
174    def get_file(self, source, dest, delete_dest=False):
175        """Retrieve a file from the host.
176
177        @param source: Remote file path (directory, file or list).
178        @param dest: Local file path (directory, file or list).
179        @param delete_dest: Delete files in remote path that are not in local
180            path.
181        """
182        raise NotImplementedError('Get file not implemented!')
183
184
185    def send_file(self, source, dest, delete_dest=False, excludes=None):
186        """Send a file to the host.
187
188        @param source: Local file path (directory, file or list).
189        @param dest: Remote file path (directory, file or list).
190        @param delete_dest: Delete files in remote path that are not in local
191                path.
192        @param excludes: A list of file pattern that matches files not to be
193                         sent. `send_file` will fail if exclude is not
194                         supported.
195        """
196        raise NotImplementedError('Send file not implemented!')
197
198
199    def get_tmp_dir(self):
200        """Create a temporary directory on the host.
201        """
202        raise NotImplementedError('Get temp dir not implemented!')
203
204
205    def is_up(self):
206        """Confirm the host is online.
207        """
208        raise NotImplementedError('Is up not implemented!')
209
210
211    def is_shutting_down(self):
212        """ Indicates is a machine is currently shutting down. """
213        return False
214
215
216    def get_wait_up_processes(self):
217        """ Gets the list of local processes to wait for in wait_up. """
218        get_config = global_config.global_config.get_config_value
219        proc_list = get_config("HOSTS", "wait_up_processes",
220                               default="").strip()
221        processes = set(p.strip() for p in proc_list.split(","))
222        processes.discard("")
223        return processes
224
225
226    def get_boot_id(self, timeout=60):
227        """ Get a unique ID associated with the current boot.
228
229        Should return a string with the semantics such that two separate
230        calls to Host.get_boot_id() return the same string if the host did
231        not reboot between the two calls, and two different strings if it
232        has rebooted at least once between the two calls.
233
234        @param timeout The number of seconds to wait before timing out.
235
236        @return A string unique to this boot or None if not available."""
237        BOOT_ID_FILE = '/proc/sys/kernel/random/boot_id'
238        NO_ID_MSG = 'no boot_id available'
239        cmd = 'if [ -f %r ]; then cat %r; else echo %r; fi' % (
240                BOOT_ID_FILE, BOOT_ID_FILE, NO_ID_MSG)
241        boot_id = self.run(cmd, timeout=timeout).stdout.strip()
242        if boot_id == NO_ID_MSG:
243            return None
244        return boot_id
245
246
247    def wait_up(self, timeout=None):
248        """Wait for the host to come up.
249
250        @param timeout: Max seconds to wait.
251        """
252        raise NotImplementedError('Wait up not implemented!')
253
254
255    def wait_down(self, timeout=None, warning_timer=None, old_boot_id=None):
256        """Wait for the host to go down.
257
258        @param timeout: Max seconds to wait before returning.
259        @param warning_timer: Seconds before warning host is not down.
260        @param old_boot_id: Result of self.get_boot_id() before shutdown.
261        """
262        raise NotImplementedError('Wait down not implemented!')
263
264
265    def _construct_host_metadata(self, type_str):
266        """Returns dict of metadata with type_str, hostname, time_recorded.
267
268        @param type_str: String representing _type field in es db.
269            For example: type_str='reboot_total'.
270        """
271        metadata = {
272            'hostname': self.hostname,
273            'time_recorded': time.time(),
274            '_type': type_str,
275        }
276        return metadata
277
278
279    def wait_for_restart(self, timeout=DEFAULT_REBOOT_TIMEOUT,
280                         down_timeout=WAIT_DOWN_REBOOT_TIMEOUT,
281                         down_warning=WAIT_DOWN_REBOOT_WARNING,
282                         log_failure=True, old_boot_id=None, **dargs):
283        """Wait for the host to come back from a reboot.
284
285        This is a generic implementation based entirely on wait_up and
286        wait_down.
287
288        @param timeout: Max seconds to wait for reboot to start.
289        @param down_timeout: Max seconds to wait for host to go down.
290        @param down_warning: Seconds to wait before warning host hasn't gone
291            down.
292        @param log_failure: bool(Log when host does not go down.)
293        @param old_boot_id: Result of self.get_boot_id() before restart.
294        @param **dargs: Extra arguments to reboot_followup.
295
296        @raises AutoservRebootError if host does not come back up.
297        """
298        if not self.wait_down(timeout=down_timeout,
299                              warning_timer=down_warning,
300                              old_boot_id=old_boot_id):
301            if log_failure:
302                self.record("ABORT", None, "reboot.verify", "shut down failed")
303            raise error.AutoservShutdownError("Host did not shut down")
304        if self.wait_up(timeout):
305            self.record("GOOD", None, "reboot.verify")
306            self.reboot_followup(**dargs)
307        else:
308            self.record("ABORT", None, "reboot.verify",
309                        "Host did not return from reboot")
310            raise error.AutoservRebootError("Host did not return from reboot")
311
312
313    def verify(self):
314        """Check if host is in good state.
315        """
316        self.verify_hardware()
317        self.verify_connectivity()
318        self.verify_software()
319
320
321    def verify_hardware(self):
322        """Check host hardware.
323        """
324        pass
325
326
327    def verify_connectivity(self):
328        """Check host network connectivity.
329        """
330        pass
331
332
333    def verify_software(self):
334        """Check host software.
335        """
336        pass
337
338
339    def check_diskspace(self, path, gb):
340        """Raises an error if path does not have at least gb GB free.
341
342        @param path The path to check for free disk space.
343        @param gb A floating point number to compare with a granularity
344            of 1 MB.
345
346        1000 based SI units are used.
347
348        @raises AutoservDiskFullHostError if path has less than gb GB free.
349        @raises AutoservDirectoryNotFoundError if path is not a valid directory.
350        @raises AutoservDiskSizeUnknownError the return from du is not parsed
351            correctly.
352        """
353        one_mb = 10 ** 6  # Bytes (SI unit).
354        mb_per_gb = 1000.0
355        logging.info('Checking for >= %s GB of space under %s on machine %s',
356                     gb, path, self.hostname)
357
358        if not self.path_exists(path):
359            msg = 'Path does not exist on host: %s' % path
360            logging.warning(msg)
361            raise error.AutoservDirectoryNotFoundError(msg)
362
363        cmd = 'df -PB %d %s | tail -1' % (one_mb, path)
364        df = self.run(cmd).stdout.split()
365        try:
366            free_space_gb = int(df[3]) / mb_per_gb
367        except (IndexError, ValueError):
368            msg = ('Could not determine the size of %s. '
369                   'Output from df: %s') % (path, df)
370            logging.error(msg)
371            raise error.AutoservDiskSizeUnknownError(msg)
372
373        if free_space_gb < gb:
374            raise error.AutoservDiskFullHostError(path, gb, free_space_gb)
375        else:
376            logging.info('Found %s GB >= %s GB of space under %s on machine %s',
377                free_space_gb, gb, path, self.hostname)
378
379
380    def check_inodes(self, path, min_kilo_inodes):
381        """Raises an error if a file system is short on i-nodes.
382
383        @param path The path to check for free i-nodes.
384        @param min_kilo_inodes Minimum number of i-nodes required,
385                               in units of 1000 i-nodes.
386
387        @raises AutoservNoFreeInodesError If the minimum required
388                                  i-node count isn't available.
389        """
390        min_inodes = 1000 * min_kilo_inodes
391        logging.info('Checking for >= %d i-nodes under %s '
392                     'on machine %s', min_inodes, path, self.hostname)
393        df = self.run('df -Pi %s | tail -1' % path).stdout.split()
394        free_inodes = int(df[3])
395        if free_inodes < min_inodes:
396            raise error.AutoservNoFreeInodesError(path, min_inodes,
397                                                  free_inodes)
398        else:
399            logging.info('Found %d >= %d i-nodes under %s on '
400                         'machine %s', free_inodes, min_inodes,
401                         path, self.hostname)
402
403
404    def erase_dir_contents(self, path, ignore_status=True, timeout=3600):
405        """Empty a given directory path contents.
406
407        @param path: Path to empty.
408        @param ignore_status: Ignore the exit status from run.
409        @param timeout: Max seconds to allow command to complete.
410        """
411        rm_cmd = 'find "%s" -mindepth 1 -maxdepth 1 -print0 | xargs -0 rm -rf'
412        self.run(rm_cmd % path, ignore_status=ignore_status, timeout=timeout)
413
414
415    def repair(self):
416        """Try and get the host to pass `self.verify()`."""
417        self.verify()
418
419
420    def disable_ipfilters(self):
421        """Allow all network packets in and out of the host."""
422        self.run('iptables-save > /tmp/iptable-rules')
423        self.run('iptables -P INPUT ACCEPT')
424        self.run('iptables -P FORWARD ACCEPT')
425        self.run('iptables -P OUTPUT ACCEPT')
426
427
428    def enable_ipfilters(self):
429        """Re-enable the IP filters disabled from disable_ipfilters()"""
430        if self.path_exists('/tmp/iptable-rules'):
431            self.run('iptables-restore < /tmp/iptable-rules')
432
433
434    def cleanup(self):
435        """Restore host to clean state.
436        """
437        pass
438
439
440    def machine_install(self):
441        """Install on the host.
442        """
443        raise NotImplementedError('Machine install not implemented!')
444
445
446    def install(self, installableObject):
447        """Call install on a thing.
448
449        @param installableObject: Thing with install method that will accept our
450            self.
451        """
452        installableObject.install(self)
453
454
455    def get_autodir(self):
456        raise NotImplementedError('Get autodir not implemented!')
457
458
459    def set_autodir(self):
460        raise NotImplementedError('Set autodir not implemented!')
461
462
463    def start_loggers(self):
464        """ Called to start continuous host logging. """
465        pass
466
467
468    def stop_loggers(self):
469        """ Called to stop continuous host logging. """
470        pass
471
472
473    # some extra methods simplify the retrieval of information about the
474    # Host machine, with generic implementations based on run(). subclasses
475    # should feel free to override these if they can provide better
476    # implementations for their specific Host types
477
478    def get_num_cpu(self):
479        """ Get the number of CPUs in the host according to /proc/cpuinfo. """
480        proc_cpuinfo = self.run('cat /proc/cpuinfo',
481                                stdout_tee=open(os.devnull, 'w')).stdout
482        cpus = 0
483        for line in proc_cpuinfo.splitlines():
484            if line.startswith('processor'):
485                cpus += 1
486        return cpus
487
488
489    def get_arch(self):
490        """ Get the hardware architecture of the remote machine. """
491        cmd_uname = path_utils.must_be_installed('/bin/uname', host=self)
492        arch = self.run('%s -m' % cmd_uname).stdout.rstrip()
493        if re.match(r'i\d86$', arch):
494            arch = 'i386'
495        return arch
496
497
498    def get_kernel_ver(self):
499        """ Get the kernel version of the remote machine. """
500        cmd_uname = path_utils.must_be_installed('/bin/uname', host=self)
501        return self.run('%s -r' % cmd_uname).stdout.rstrip()
502
503
504    def get_cmdline(self):
505        """ Get the kernel command line of the remote machine. """
506        return self.run('cat /proc/cmdline').stdout.rstrip()
507
508
509    def get_meminfo(self):
510        """ Get the kernel memory info (/proc/meminfo) of the remote machine
511        and return a dictionary mapping the various statistics. """
512        meminfo_dict = {}
513        meminfo = self.run('cat /proc/meminfo').stdout.splitlines()
514        for key, val in (line.split(':', 1) for line in meminfo):
515            meminfo_dict[key.strip()] = val.strip()
516        return meminfo_dict
517
518
519    def path_exists(self, path):
520        """Determine if path exists on the remote machine.
521
522        @param path: path to check
523
524        @return: bool(path exists)"""
525        result = self.run('test -e "%s"' % utils.sh_escape(path),
526                          ignore_status=True)
527        return result.exit_status == 0
528
529
530    # some extra helpers for doing job-related operations
531
532    def record(self, *args, **dargs):
533        """ Helper method for recording status logs against Host.job that
534        silently becomes a NOP if Host.job is not available. The args and
535        dargs are passed on to Host.job.record unchanged. """
536        if self.job:
537            self.job.record(*args, **dargs)
538
539
540    def log_kernel(self):
541        """ Helper method for logging kernel information into the status logs.
542        Intended for cases where the "current" kernel is not really defined
543        and we want to explicitly log it. Does nothing if this host isn't
544        actually associated with a job. """
545        if self.job:
546            kernel = self.get_kernel_ver()
547            self.job.record("INFO", None, None,
548                            optional_fields={"kernel": kernel})
549
550
551    def log_op(self, op, op_func):
552        """ Decorator for wrapping a management operaiton in a group for status
553        logging purposes.
554
555        @param op: name of the operation.
556        @param op_func: a function that carries out the operation
557                        (reboot, suspend)
558        """
559        if self.job and not hasattr(self, "RUNNING_LOG_OP"):
560            self.RUNNING_LOG_OP = True
561            try:
562                self.job.run_op(op, op_func, self.get_kernel_ver)
563            finally:
564                del self.RUNNING_LOG_OP
565        else:
566            op_func()
567
568
569    def list_files_glob(self, glob):
570        """Get a list of files on a remote host given a glob pattern path.
571
572        @param glob: pattern
573
574        @return: list of files
575        """
576        SCRIPT = ("python -c 'import cPickle, glob, sys;"
577                  "cPickle.dump(glob.glob(sys.argv[1]), sys.stdout, 0)'")
578        output = self.run(SCRIPT, args=(glob,), stdout_tee=None,
579                          timeout=60).stdout
580        return cPickle.loads(output)
581
582
583    def symlink_closure(self, paths):
584        """
585        Given a sequence of path strings, return the set of all paths that
586        can be reached from the initial set by following symlinks.
587
588        @param paths: sequence of path strings.
589        @return: a sequence of path strings that are all the unique paths that
590                can be reached from the given ones after following symlinks.
591        """
592        SCRIPT = ("python -c 'import cPickle, os, sys\n"
593                  "paths = cPickle.load(sys.stdin)\n"
594                  "closure = {}\n"
595                  "while paths:\n"
596                  "    path = paths.keys()[0]\n"
597                  "    del paths[path]\n"
598                  "    if not os.path.exists(path):\n"
599                  "        continue\n"
600                  "    closure[path] = None\n"
601                  "    if os.path.islink(path):\n"
602                  "        link_to = os.path.join(os.path.dirname(path),\n"
603                  "                               os.readlink(path))\n"
604                  "        if link_to not in closure.keys():\n"
605                  "            paths[link_to] = None\n"
606                  "cPickle.dump(closure.keys(), sys.stdout, 0)'")
607        input_data = cPickle.dumps(dict((path, None) for path in paths), 0)
608        output = self.run(SCRIPT, stdout_tee=None, stdin=input_data,
609                          timeout=60).stdout
610        return cPickle.loads(output)
611
612
613    def cleanup_kernels(self, boot_dir='/boot'):
614        """
615        Remove any kernel image and associated files (vmlinux, system.map,
616        modules) for any image found in the boot directory that is not
617        referenced by entries in the bootloader configuration.
618
619        @param boot_dir: boot directory path string, default '/boot'
620        """
621        # find all the vmlinuz images referenced by the bootloader
622        vmlinuz_prefix = os.path.join(boot_dir, 'vmlinuz-')
623        boot_info = self.bootloader.get_entries()
624        used_kernver = [boot['kernel'][len(vmlinuz_prefix):]
625                        for boot in boot_info.itervalues()]
626
627        # find all the unused vmlinuz images in /boot
628        all_vmlinuz = self.list_files_glob(vmlinuz_prefix + '*')
629        used_vmlinuz = self.symlink_closure(vmlinuz_prefix + kernver
630                                            for kernver in used_kernver)
631        unused_vmlinuz = set(all_vmlinuz) - set(used_vmlinuz)
632
633        # find all the unused vmlinux images in /boot
634        vmlinux_prefix = os.path.join(boot_dir, 'vmlinux-')
635        all_vmlinux = self.list_files_glob(vmlinux_prefix + '*')
636        used_vmlinux = self.symlink_closure(vmlinux_prefix + kernver
637                                            for kernver in used_kernver)
638        unused_vmlinux = set(all_vmlinux) - set(used_vmlinux)
639
640        # find all the unused System.map files in /boot
641        systemmap_prefix = os.path.join(boot_dir, 'System.map-')
642        all_system_map = self.list_files_glob(systemmap_prefix + '*')
643        used_system_map = self.symlink_closure(
644            systemmap_prefix + kernver for kernver in used_kernver)
645        unused_system_map = set(all_system_map) - set(used_system_map)
646
647        # find all the module directories associated with unused kernels
648        modules_prefix = '/lib/modules/'
649        all_moddirs = [dir for dir in self.list_files_glob(modules_prefix + '*')
650                       if re.match(modules_prefix + r'\d+\.\d+\.\d+.*', dir)]
651        used_moddirs = self.symlink_closure(modules_prefix + kernver
652                                            for kernver in used_kernver)
653        unused_moddirs = set(all_moddirs) - set(used_moddirs)
654
655        # remove all the vmlinuz files we don't use
656        # TODO: if needed this should become package manager agnostic
657        for vmlinuz in unused_vmlinuz:
658            # try and get an rpm package name
659            rpm = self.run('rpm -qf', args=(vmlinuz,),
660                           ignore_status=True, timeout=120)
661            if rpm.exit_status == 0:
662                packages = set(line.strip() for line in
663                               rpm.stdout.splitlines())
664                # if we found some package names, try to remove them
665                for package in packages:
666                    self.run('rpm -e', args=(package,),
667                             ignore_status=True, timeout=120)
668            # remove the image files anyway, even if rpm didn't
669            self.run('rm -f', args=(vmlinuz,),
670                     ignore_status=True, timeout=120)
671
672        # remove all the vmlinux and System.map files left over
673        for f in (unused_vmlinux | unused_system_map):
674            self.run('rm -f', args=(f,),
675                     ignore_status=True, timeout=120)
676
677        # remove all unused module directories
678        # the regex match should keep us safe from removing the wrong files
679        for moddir in unused_moddirs:
680            self.run('rm -fr', args=(moddir,), ignore_status=True)
681
682
683    def get_attributes_to_clear_before_provision(self):
684        """Get a list of attributes to be cleared before machine_install starts.
685
686        If provision runs in a lab environment, it is necessary to clear certain
687        host attributes for the host in afe_host_attributes table. For example,
688        `job_repo_url` is a devserver url pointed to autotest packages for
689        CrosHost, it needs to be removed before provision starts for tests to
690        run reliably.
691        For ADBHost, the job repo url has a different format, i.e., appended by
692        adb_serial, so this method should be overriden in ADBHost.
693        """
694        return ['job_repo_url']
695
696
697    def get_platform(self):
698        """Determine the correct platform label for this host.
699
700        @return: A string representing this host's platform.
701        """
702        raise NotImplementedError("Get platform not implemented!")
703
704
705    def get_labels(self):
706        """Return a list of the labels gathered from the devices connected.
707
708        @return: A list of strings that denote the labels from all the devices
709        connected.
710        """
711        raise NotImplementedError("Get labels not implemented!")
712
713
714    def check_cached_up_status(self, expiration_seconds):
715        """Check if the DUT responded to ping in the past `expiration_seconds`.
716
717        @param expiration_seconds: The number of seconds to keep the cached
718                status of whether the DUT responded to ping.
719        @return: True if the DUT has responded to ping during the past
720                 `expiration_seconds`.
721        """
722        raise NotImplementedError("check_cached_up_status not implemented!")
723