class AccountManagerTest(unittest.TestCase): CORRELATE = AccountManager def setUp(self): self.am = AccountManager() self.data = {} self.account = Account('user', 'test') def testConstructor(self): self.assertEqual(0, self.am.default_pool.n_accounts()) def testReset(self): self.testAddAccount() self.am.reset() self.assertEqual(self.am.default_pool.n_accounts(), 0) def testAddAccount(self): self.assertEqual(0, self.am.default_pool.n_accounts()) account = Account('user', 'test') self.am.add_account(account) self.assertEqual(1, self.am.default_pool.n_accounts()) def testAddPool(self): self.assertEqual(0, self.am.default_pool.n_accounts()) account = Account('user', 'test') self.am.add_account(account) self.assertEqual(1, self.am.default_pool.n_accounts()) def match_cb(host): self.data['match-called'] = True self.data['host'] = host return True # Replace the default pool. pool1 = AccountPool() self.am.add_pool(pool1) self.assertEqual(self.am.default_pool, pool1) # Add another pool, making sure that it does not replace # the default pool. pool2 = AccountPool() pool2.add_account(self.account) self.am.add_pool(pool2, match_cb) self.assertEqual(self.am.default_pool, pool1) def testGetAccountFromHash(self): pool1 = AccountPool() acc1 = Account('user1') pool1.add_account(acc1) self.am.add_pool(pool1) acc2 = Account('user2') self.am.add_account(acc2) self.assertEqual(self.am.get_account_from_hash(acc1.__hash__()), acc1) self.assertEqual(self.am.get_account_from_hash(acc2.__hash__()), acc2) def testAcquireAccount(self): account1 = Account('user1', 'test') self.assertRaises(ValueError, self.am.acquire_account) self.am.add_account(account1) self.assertEqual(self.am.acquire_account(), account1) account1.release() account2 = Account('user2', 'test') self.am.add_account(account2) self.assertEqual(self.am.acquire_account(account2), account2) account2.release() account = self.am.acquire_account() self.assertNotEqual(account, None) account.release() account3 = Account('user3', 'test') pool = AccountPool() pool.add_account(account3) self.am.add_pool(pool) self.assertEqual(self.am.acquire_account(account2), account2) account2.release() self.assertEqual(self.am.acquire_account(account3), account3) account3.release() account = self.am.acquire_account() self.assertNotEqual(account, None) account.release() def testAcquireAccountFor(self): self.testAddPool() def start_cb(data, conn): data['start-called'] = True # Make sure that pool2 is chosen (because the match function # returns True). account = self.am.acquire_account_for('myhost') account.release() self.assertEqual(self.data, {'match-called': True, 'host': 'myhost'}) self.assertEqual(self.account, account) def testReleaseAccounts(self): account1 = Account('foo') pool = AccountPool() pool.add_account(account1) pool.acquire_account(account1, 'one') self.am.add_pool(pool, lambda x: None) account2 = Account('bar') self.am.add_account(account2) self.am.acquire_account(account2, 'two') self.assert_(account1 not in pool.unlocked_accounts) self.assert_(account2 not in self.am.default_pool.unlocked_accounts) self.am.release_accounts('two') self.assert_(account1 not in pool.unlocked_accounts) self.assert_(account2 in self.am.default_pool.unlocked_accounts) self.am.release_accounts('one') self.assert_(account1 in pool.unlocked_accounts) self.assert_(account2 in self.am.default_pool.unlocked_accounts)
class Queue(object): """ Manages hosts/tasks, accounts, connections, and threads. """ def __init__(self, domain="", verbose=1, mode="threading", max_threads=1, stdout=sys.stdout, stderr=sys.stderr): """ Constructor. All arguments should be passed as keyword arguments. Depending on the verbosity level, the following types of output are written to stdout/stderr (or to whatever else is passed in the stdout/stderr arguments): - S = status bar - L = live conversation - D = debug messages - E = errors - ! = errors with tracebacks - F = fatal errors with tracebacks The output types are mapped depending on the verbosity as follows: - verbose = -1: stdout = None, stderr = F - verbose = 0: stdout = None, stderr = EF - verbose = 1, max_threads = 1: stdout = L, stderr = EF - verbose = 1, max_threads = n: stdout = S, stderr = EF - verbose >= 2, max_threads = 1: stdout = DL, stderr = !F - verbose >= 2, max_threads = n: stdout = DS, stderr = !F @type domain: str @param domain: The default domain of the contacted hosts. @type verbose: int @param verbose: The verbosity level. @type mode: str @param mode: 'multiprocessing' or 'threading' @type max_threads: int @param max_threads: The maximum number of concurrent threads. @type stdout: file @param stdout: The output channel, defaults to sys.stdout. @type stderr: file @param stderr: The error channel, defaults to sys.stderr. """ self.workqueue = WorkQueue(mode=mode) self.account_manager = AccountManager() self.pipe_handlers = weakref.WeakValueDictionary() self.domain = domain self.verbose = verbose self.stdout = stdout self.stderr = stderr self.devnull = open(os.devnull, "w") self.channel_map = {"fatal_errors": self.stderr, "debug": self.stdout} self.completed = 0 self.total = 0 self.failed = 0 self.status_bar_length = 0 self.set_max_threads(max_threads) # Listen to what the workqueue is doing. self.workqueue.job_init_event.listen(self._on_job_init) self.workqueue.job_started_event.listen(self._on_job_started) self.workqueue.job_error_event.listen(self._on_job_error) self.workqueue.job_succeeded_event.listen(self._on_job_succeeded) self.workqueue.job_aborted_event.listen(self._on_job_aborted) def _update_verbosity(self): if self.verbose < 0: self.channel_map["status_bar"] = self.devnull self.channel_map["connection"] = self.devnull self.channel_map["errors"] = self.devnull self.channel_map["tracebacks"] = self.devnull elif self.verbose == 0: self.channel_map["status_bar"] = self.devnull self.channel_map["connection"] = self.devnull self.channel_map["errors"] = self.stderr self.channel_map["tracebacks"] = self.devnull elif self.verbose == 1 and self.get_max_threads() == 1: self.channel_map["status_bar"] = self.devnull self.channel_map["connection"] = self.stdout self.channel_map["errors"] = self.stderr self.channel_map["tracebacks"] = self.devnull elif self.verbose == 1: self.channel_map["status_bar"] = self.stdout self.channel_map["connection"] = self.devnull self.channel_map["errors"] = self.stderr self.channel_map["tracebacks"] = self.devnull elif self.verbose >= 2 and self.get_max_threads() == 1: self.channel_map["status_bar"] = self.devnull self.channel_map["connection"] = self.stdout self.channel_map["errors"] = self.stderr self.channel_map["tracebacks"] = self.stderr elif self.verbose >= 2: self.channel_map["status_bar"] = self.stdout self.channel_map["connection"] = self.devnull self.channel_map["errors"] = self.stderr self.channel_map["tracebacks"] = self.stderr def _write(self, channel, msg): self.channel_map[channel].write(msg) self.channel_map[channel].flush() def _create_pipe(self): """ Creates a new pipe and returns the child end of the connection. To request an account from the pipe, use:: pipe = queue._create_pipe() # Let the account manager choose an account. pipe.send(('acquire-account-for-host', host)) account = pipe.recv() ... pipe.send(('release-account', account.id())) # Or acquire a specific account. pipe.send(('acquire-account', account.id())) account = pipe.recv() ... pipe.send(('release-account', account.id())) pipe.close() """ child = _PipeHandler(self.account_manager) self.pipe_handlers[id(child)] = child child.start() return child.to_parent def _del_status_bar(self): if self.status_bar_length == 0: return self._write("status_bar", "\b \b" * self.status_bar_length) self.status_bar_length = 0 def get_progress(self): """ Returns the progress in percent. @rtype: float @return: The progress in percent. """ if self.total == 0: return 0.0 return 100.0 / self.total * self.completed def _print_status_bar(self, exclude=None): if self.total == 0: return percent = 100.0 / self.total * self.completed progress = "%d/%d (%d%%)" % (self.completed, self.total, percent) jobs = self.workqueue.get_running_jobs() running = "|".join([j.name for j in jobs if j.name != exclude]) if not running: self.status_bar_length = 0 return rows, cols = get_terminal_size() text = "In progress: [%s] %s" % (running, progress) overflow = len(text) - cols if overflow > 0: cont = "..." overflow += len(cont) + 1 strlen = len(running) partlen = (strlen / 2) - (overflow / 2) head = running[:partlen] tail = running[-partlen:] running = head + cont + tail text = "In progress: [%s] %s" % (running, progress) self._write("status_bar", text) self.status_bar_length = len(text) def _print(self, channel, msg): self._del_status_bar() self._write(channel, msg + "\n") self._print_status_bar() def _dbg(self, level, msg): if level > self.verbose: return self._print("debug", msg) def _on_job_init(self, job): if job.data is None: job.data = {} job.data["pipe"] = self._create_pipe() job.data["stdout"] = self.channel_map["connection"] def _on_job_destroy(self, job): job.data["pipe"].close() def _on_job_started(self, job): self._del_status_bar() self._print_status_bar() def _on_job_error(self, job, exc_info): msg = job.name + " error: " + str(exc_info[1]) trace = "".join(format_exception(*exc_info)) self._print("errors", msg) if _is_recoverable_error(exc_info[0]): self._print("tracebacks", trace) else: self._print("fatal_errors", trace) def _on_job_succeeded(self, job): self._on_job_destroy(job) self.completed += 1 self._print("status_bar", job.name + " succeeded.") self._dbg(2, job.name + " job is done.") self._del_status_bar() self._print_status_bar(exclude=job.name) def _on_job_aborted(self, job): self._on_job_destroy(job) self.completed += 1 self.failed += 1 self._print("errors", job.name + " finally failed.") self._del_status_bar() self._print_status_bar(exclude=job.name) def set_max_threads(self, n_connections): """ Sets the maximum number of concurrent connections. @type n_connections: int @param n_connections: The maximum number of connections. """ self.workqueue.set_max_threads(n_connections) self._update_verbosity() def get_max_threads(self): """ Returns the maximum number of concurrent threads. @rtype: int @return: The maximum number of connections. """ return self.workqueue.get_max_threads() def add_account_pool(self, pool, match=None): """ Adds a new account pool. If the given match argument is None, the pool the default pool. Otherwise, the match argument is a callback function that is invoked to decide whether or not the given pool should be used for a host. When Exscript logs into a host, the account is chosen in the following order: # Exscript checks whether an account was attached to the L{Host} object using L{Host.set_account()}), and uses that. # If the L{Host} has no account attached, Exscript walks through all pools that were passed to L{Queue.add_account_pool()}. For each pool, it passes the L{Host} to the function in the given match argument. If the return value is True, the account pool is used to acquire an account. (Accounts within each pool are taken in a round-robin fashion.) # If no matching account pool is found, an account is taken from the default account pool. # Finally, if all that fails and the default account pool contains no accounts, an error is raised. Example usage:: def do_nothing(conn): conn.autoinit() def use_this_pool(host): return host.get_name().startswith('foo') default_pool = AccountPool() default_pool.add_account(Account('default-user', 'password')) other_pool = AccountPool() other_pool.add_account(Account('user', 'password')) queue = Queue() queue.add_account_pool(default_pool) queue.add_account_pool(other_pool, use_this_pool) host = Host('localhost') queue.run(host, do_nothing) In the example code, the host has no account attached. As a result, the queue checks whether use_this_pool() returns True. Because the hostname does not start with 'foo', the function returns False, and Exscript takes the 'default-user' account from the default pool. @type pool: AccountPool @param pool: The account pool that is added. @type match: callable @param match: A callback to check if the pool should be used. """ self.account_manager.add_pool(pool, match) def add_account(self, account): """ Adds the given account to the default account pool that Exscript uses to log into all hosts that have no specific L{Account} attached. @type account: Account @param account: The account that is added. """ self.account_manager.add_account(account) def is_completed(self): """ Returns True if the task is completed, False otherwise. In other words, this methods returns True if the queue is empty. @rtype: bool @return: Whether all tasks are completed. """ return self.workqueue.get_length() == 0 def join(self): """ Waits until all jobs are completed. """ self._dbg(2, "Waiting for the queue to finish.") self.workqueue.wait_until_done() for child in self.pipe_handlers.values(): child.join() self._del_status_bar() self._print_status_bar() gc.collect() def shutdown(self, force=False): """ Stop executing any further jobs. If the force argument is True, the function does not wait until any queued jobs are completed but stops immediately. After emptying the queue it is restarted, so you may still call run() after using this method. @type force: bool @param force: Whether to wait until all jobs were processed. """ if not force: self.join() self._dbg(2, "Shutting down queue...") self.workqueue.shutdown(True) self._dbg(2, "Queue shut down.") self._del_status_bar() def destroy(self, force=False): """ Like shutdown(), but also removes all accounts, hosts, etc., and does not restart the queue. In other words, the queue can no longer be used after calling this method. @type force: bool @param force: Whether to wait until all jobs were processed. """ try: if not force: self.join() finally: self._dbg(2, "Destroying queue...") self.workqueue.destroy() self.account_manager.reset() self.completed = 0 self.total = 0 self.failed = 0 self.status_bar_length = 0 self._dbg(2, "Queue destroyed.") self._del_status_bar() def reset(self): """ Remove all accounts, hosts, etc. """ self._dbg(2, "Resetting queue...") self.account_manager.reset() self.workqueue.shutdown(True) self.completed = 0 self.total = 0 self.failed = 0 self.status_bar_length = 0 self._dbg(2, "Queue reset.") self._del_status_bar() def _run(self, hosts, callback, queue_function, *args): hosts = to_hosts(hosts, default_domain=self.domain) self.total += len(hosts) callback = _prepare_connection(callback) task = Task(self.workqueue) for host in hosts: name = host.get_name() data = {"host": host} job_id = queue_function(callback, name, *args, data=data) if job_id is not None: task.add_job_id(job_id) if task.is_completed(): self._dbg(2, "No jobs enqueued.") return None self._dbg(2, "All jobs enqueued.") return task def run(self, hosts, function, attempts=1): """ Add the given function to a queue, and call it once for each host according to the threading options. Use decorators.bind() if you also want to pass additional arguments to the callback function. Returns an object that represents the queued task, and that may be passed to is_completed() to check the status. @type hosts: string|list(string)|Host|list(Host) @param hosts: A hostname or Host object, or a list of them. @type function: function @param function: The function to execute. @type attempts: int @param attempts: The number of attempts on failure. @rtype: object @return: An object representing the task. """ return self._run(hosts, function, self.workqueue.enqueue, attempts) def run_or_ignore(self, hosts, function, attempts=1): """ Like run(), but only appends hosts that are not already in the queue. @type hosts: string|list(string)|Host|list(Host) @param hosts: A hostname or Host object, or a list of them. @type function: function @param function: The function to execute. @type attempts: int @param attempts: The number of attempts on failure. @rtype: object @return: A task object, or None if all hosts were duplicates. """ return self._run(hosts, function, self.workqueue.enqueue_or_ignore, attempts) def priority_run(self, hosts, function, attempts=1): """ Like run(), but adds the task to the front of the queue. @type hosts: string|list(string)|Host|list(Host) @param hosts: A hostname or Host object, or a list of them. @type function: function @param function: The function to execute. @type attempts: int @param attempts: The number of attempts on failure. @rtype: object @return: An object representing the task. """ return self._run(hosts, function, self.workqueue.priority_enqueue, False, attempts) def priority_run_or_raise(self, hosts, function, attempts=1): """ Like priority_run(), but if a host is already in the queue, the existing host is moved to the top of the queue instead of enqueuing the new one. @type hosts: string|list(string)|Host|list(Host) @param hosts: A hostname or Host object, or a list of them. @type function: function @param function: The function to execute. @type attempts: int @param attempts: The number of attempts on failure. @rtype: object @return: A task object, or None if all hosts were duplicates. """ return self._run(hosts, function, self.workqueue.priority_enqueue_or_raise, False, attempts) def force_run(self, hosts, function, attempts=1): """ Like priority_run(), but starts the task immediately even if that max_threads is exceeded. @type hosts: string|list(string)|Host|list(Host) @param hosts: A hostname or Host object, or a list of them. @type function: function @param function: The function to execute. @type attempts: int @param attempts: The number of attempts on failure. @rtype: object @return: An object representing the task. """ return self._run(hosts, function, self.workqueue.priority_enqueue, True, attempts) def enqueue(self, function, name=None, attempts=1): """ Places the given function in the queue and calls it as soon as a thread is available. To pass additional arguments to the callback, use Python's functools.partial(). @type function: function @param function: The function to execute. @type name: string @param name: A name for the task. @type attempts: int @param attempts: The number of attempts on failure. @rtype: object @return: An object representing the task. """ self.total += 1 task = Task(self.workqueue) job_id = self.workqueue.enqueue(function, name, attempts) if job_id is not None: task.add_job_id(job_id) self._dbg(2, "Function enqueued.") return task
class Queue(object): """ Manages hosts/tasks, accounts, connections, and threads. """ def __init__(self, domain = '', verbose = 1, mode = 'threading', max_threads = 1, host_driver = None, exc_cb = None, stdout = sys.stdout, stderr = sys.stderr): """ Constructor. All arguments should be passed as keyword arguments. Depending on the verbosity level, the following types of output are written to stdout/stderr (or to whatever else is passed in the stdout/stderr arguments): - S = status bar - L = live conversation - D = debug messages - E = errors - ! = errors with tracebacks - F = fatal errors with tracebacks The output types are mapped depending on the verbosity as follows: - verbose = -1: stdout = None, stderr = F - verbose = 0: stdout = None, stderr = EF - verbose = 1, max_threads = 1: stdout = L, stderr = EF - verbose = 1, max_threads = n: stdout = S, stderr = EF - verbose >= 2, max_threads = 1: stdout = DL, stderr = !F - verbose >= 2, max_threads = n: stdout = DS, stderr = !F :type domain: str :param domain: The default domain of the contacted hosts. :type verbose: int :param verbose: The verbosity level. :type mode: str :param mode: 'multiprocessing' or 'threading' :type max_threads: int :param max_threads: The maximum number of concurrent threads. :type host_driver: str :param host_driver: driver name like "ios" for manual override :type exc_cb: func(jobname, exc_info) :param exc_cb: callback function to call on exceptions :type stdout: file :param stdout: The output channel, defaults to sys.stdout. :type stderr: file :param stderr: The error channel, defaults to sys.stderr. """ self.workqueue = WorkQueue(mode = mode) self.account_manager = AccountManager() self.pipe_handlers = weakref.WeakValueDictionary() self.domain = domain self.verbose = verbose self.stdout = stdout self.stderr = stderr self.host_driver = host_driver self.exc_cb = exc_cb self.devnull = open(os.devnull, 'w') self.channel_map = {'fatal_errors': self.stderr, 'debug': self.stdout} self.completed = 0 self.total = 0 self.failed = 0 self.status_bar_length = 0 self.set_max_threads(max_threads) # Listen to what the workqueue is doing. self.workqueue.job_init_event.listen(self._on_job_init) self.workqueue.job_started_event.listen(self._on_job_started) self.workqueue.job_error_event.listen(self._on_job_error) self.workqueue.job_succeeded_event.listen(self._on_job_succeeded) self.workqueue.job_aborted_event.listen(self._on_job_aborted) def _update_verbosity(self): if self.verbose < 0: self.channel_map['status_bar'] = self.devnull self.channel_map['connection'] = self.devnull self.channel_map['errors'] = self.devnull self.channel_map['tracebacks'] = self.devnull elif self.verbose == 0: self.channel_map['status_bar'] = self.devnull self.channel_map['connection'] = self.devnull self.channel_map['errors'] = self.stderr self.channel_map['tracebacks'] = self.devnull elif self.verbose == 1 and self.get_max_threads() == 1: self.channel_map['status_bar'] = self.devnull self.channel_map['connection'] = self.stdout self.channel_map['errors'] = self.stderr self.channel_map['tracebacks'] = self.devnull elif self.verbose == 1: self.channel_map['status_bar'] = self.stdout self.channel_map['connection'] = self.devnull self.channel_map['errors'] = self.stderr self.channel_map['tracebacks'] = self.devnull elif self.verbose >= 2 and self.get_max_threads() == 1: self.channel_map['status_bar'] = self.devnull self.channel_map['connection'] = self.stdout self.channel_map['errors'] = self.stderr self.channel_map['tracebacks'] = self.stderr elif self.verbose >= 2: self.channel_map['status_bar'] = self.stdout self.channel_map['connection'] = self.devnull self.channel_map['errors'] = self.stderr self.channel_map['tracebacks'] = self.stderr def _write(self, channel, msg): self.channel_map[channel].write(msg) self.channel_map[channel].flush() def _create_pipe(self): """ Creates a new pipe and returns the child end of the connection. To request an account from the pipe, use:: pipe = queue._create_pipe() # Let the account manager choose an account. pipe.send(('acquire-account-for-host', host)) account = pipe.recv() ... pipe.send(('release-account', account.id())) # Or acquire a specific account. pipe.send(('acquire-account', account.id())) account = pipe.recv() ... pipe.send(('release-account', account.id())) pipe.close() """ child = _PipeHandler(self.account_manager) self.pipe_handlers[id(child)] = child child.start() return child.to_parent def _del_status_bar(self): if self.status_bar_length == 0: return self._write('status_bar', '\b \b' * self.status_bar_length) self.status_bar_length = 0 def get_progress(self): """ Returns the progress in percent. :rtype: float :return: The progress in percent. """ if self.total == 0: return 0.0 return 100.0 / self.total * self.completed def _print_status_bar(self, exclude = None): if self.total == 0: return percent = 100.0 / self.total * self.completed progress = '%d/%d (%d%%)' % (self.completed, self.total, percent) jobs = self.workqueue.get_running_jobs() running = '|'.join([j.name for j in jobs if j.name != exclude]) if not running: self.status_bar_length = 0 return rows, cols = get_terminal_size() text = 'In progress: [%s] %s' % (running, progress) overflow = len(text) - cols if overflow > 0: cont = '...' overflow += len(cont) + 1 strlen = len(running) partlen = (strlen / 2) - (overflow / 2) head = running[:partlen] tail = running[-partlen:] running = head + cont + tail text = 'In progress: [%s] %s' % (running, progress) self._write('status_bar', text) self.status_bar_length = len(text) def _print(self, channel, msg): self._del_status_bar() self._write(channel, msg + '\n') self._print_status_bar() def _dbg(self, level, msg): if level > self.verbose: return self._print('debug', msg) def _on_job_init(self, job): if job.data is None: job.data = {} job.data['pipe'] = self._create_pipe() job.data['stdout'] = self.channel_map['connection'] def _on_job_destroy(self, job): job.data['pipe'].close() def _on_job_started(self, job): self._del_status_bar() self._print_status_bar() def _on_job_error(self, job, exc_info): msg = job.name + ' error: ' + str(exc_info[1]) trace = ''.join(format_exception(*exc_info)) if self.exc_cb: self.exc_cb(job.name, exc_info) self._print('errors', msg) if _is_recoverable_error(exc_info[0]): self._print('tracebacks', trace) else: self._print('fatal_errors', trace) def _on_job_succeeded(self, job): self._on_job_destroy(job) self.completed += 1 self._print('status_bar', job.name + ' succeeded.') self._dbg(2, job.name + ' job is done.') self._del_status_bar() self._print_status_bar(exclude = job.name) def _on_job_aborted(self, job): self._on_job_destroy(job) self.completed += 1 self.failed += 1 self._print('errors', job.name + ' finally failed.') self._del_status_bar() self._print_status_bar(exclude = job.name) def set_max_threads(self, n_connections): """ Sets the maximum number of concurrent connections. :type n_connections: int :param n_connections: The maximum number of connections. """ self.workqueue.set_max_threads(n_connections) self._update_verbosity() def get_max_threads(self): """ Returns the maximum number of concurrent threads. :rtype: int :return: The maximum number of connections. """ return self.workqueue.get_max_threads() def add_account_pool(self, pool, match = None): """ Adds a new account pool. If the given match argument is None, the pool the default pool. Otherwise, the match argument is a callback function that is invoked to decide whether or not the given pool should be used for a host. When Exscript logs into a host, the account is chosen in the following order: # Exscript checks whether an account was attached to the :class:`Host` object using :class:`Host.set_account()`), and uses that. # If the :class:`Host` has no account attached, Exscript walks through all pools that were passed to :class:`Queue.add_account_pool()`. For each pool, it passes the :class:`Host` to the function in the given match argument. If the return value is True, the account pool is used to acquire an account. (Accounts within each pool are taken in a round-robin fashion.) # If no matching account pool is found, an account is taken from the default account pool. # Finally, if all that fails and the default account pool contains no accounts, an error is raised. Example usage:: def do_nothing(conn): conn.autoinit() def use_this_pool(host): return host.get_name().startswith('foo') default_pool = AccountPool() default_pool.add_account(Account('default-user', 'password')) other_pool = AccountPool() other_pool.add_account(Account('user', 'password')) queue = Queue() queue.add_account_pool(default_pool) queue.add_account_pool(other_pool, use_this_pool) host = Host('localhost') queue.run(host, do_nothing) In the example code, the host has no account attached. As a result, the queue checks whether use_this_pool() returns True. Because the hostname does not start with 'foo', the function returns False, and Exscript takes the 'default-user' account from the default pool. :type pool: AccountPool :param pool: The account pool that is added. :type match: callable :param match: A callback to check if the pool should be used. """ self.account_manager.add_pool(pool, match) def add_account(self, account): """ Adds the given account to the default account pool that Exscript uses to log into all hosts that have no specific :class:`Account` attached. :type account: Account :param account: The account that is added. """ self.account_manager.add_account(account) def is_completed(self): """ Returns True if the task is completed, False otherwise. In other words, this methods returns True if the queue is empty. :rtype: bool :return: Whether all tasks are completed. """ return self.workqueue.get_length() == 0 def join(self): """ Waits until all jobs are completed. """ self._dbg(2, 'Waiting for the queue to finish.') self.workqueue.wait_until_done() for child in self.pipe_handlers.values(): child.join() self._del_status_bar() self._print_status_bar() gc.collect() def shutdown(self, force = False): """ Stop executing any further jobs. If the force argument is True, the function does not wait until any queued jobs are completed but stops immediately. After emptying the queue it is restarted, so you may still call run() after using this method. :type force: bool :param force: Whether to wait until all jobs were processed. """ if not force: self.join() self._dbg(2, 'Shutting down queue...') self.workqueue.shutdown(True) self._dbg(2, 'Queue shut down.') self._del_status_bar() def destroy(self, force = False): """ Like shutdown(), but also removes all accounts, hosts, etc., and does not restart the queue. In other words, the queue can no longer be used after calling this method. :type force: bool :param force: Whether to wait until all jobs were processed. """ try: if not force: self.join() finally: self._dbg(2, 'Destroying queue...') self.workqueue.destroy() self.account_manager.reset() self.completed = 0 self.total = 0 self.failed = 0 self.status_bar_length = 0 self._dbg(2, 'Queue destroyed.') self._del_status_bar() def reset(self): """ Remove all accounts, hosts, etc. """ self._dbg(2, 'Resetting queue...') self.account_manager.reset() self.workqueue.shutdown(True) self.completed = 0 self.total = 0 self.failed = 0 self.status_bar_length = 0 self._dbg(2, 'Queue reset.') self._del_status_bar() def _run(self, hosts, callback, queue_function, *args): hosts = to_hosts(hosts, default_domain = self.domain) self.total += len(hosts) callback = _prepare_connection(callback) task = Task(self.workqueue) for host in hosts: name = host.get_name() data = {'host': host} job_id = queue_function(callback, name, *args, data = data) if job_id is not None: task.add_job_id(job_id) if self.host_driver is not None: host.set_option('driver', self.host_driver) if task.is_completed(): self._dbg(2, 'No jobs enqueued.') return None self._dbg(2, 'All jobs enqueued.') return task def run(self, hosts, function, attempts = 1): """ Add the given function to a queue, and call it once for each host according to the threading options. Use decorators.bind() if you also want to pass additional arguments to the callback function. Returns an object that represents the queued task, and that may be passed to is_completed() to check the status. :type hosts: string|list(string)|Host|list(Host) :param hosts: A hostname or Host object, or a list of them. :type function: function :param function: The function to execute. :type attempts: int :param attempts: The number of attempts on failure. :rtype: object :return: An object representing the task. """ return self._run(hosts, function, self.workqueue.enqueue, attempts) def run_or_ignore(self, hosts, function, attempts = 1): """ Like run(), but only appends hosts that are not already in the queue. :type hosts: string|list(string)|Host|list(Host) :param hosts: A hostname or Host object, or a list of them. :type function: function :param function: The function to execute. :type attempts: int :param attempts: The number of attempts on failure. :rtype: object :return: A task object, or None if all hosts were duplicates. """ return self._run(hosts, function, self.workqueue.enqueue_or_ignore, attempts) def priority_run(self, hosts, function, attempts = 1): """ Like run(), but adds the task to the front of the queue. :type hosts: string|list(string)|Host|list(Host) :param hosts: A hostname or Host object, or a list of them. :type function: function :param function: The function to execute. :type attempts: int :param attempts: The number of attempts on failure. :rtype: object :return: An object representing the task. """ return self._run(hosts, function, self.workqueue.priority_enqueue, False, attempts) def priority_run_or_raise(self, hosts, function, attempts = 1): """ Like priority_run(), but if a host is already in the queue, the existing host is moved to the top of the queue instead of enqueuing the new one. :type hosts: string|list(string)|Host|list(Host) :param hosts: A hostname or Host object, or a list of them. :type function: function :param function: The function to execute. :type attempts: int :param attempts: The number of attempts on failure. :rtype: object :return: A task object, or None if all hosts were duplicates. """ return self._run(hosts, function, self.workqueue.priority_enqueue_or_raise, False, attempts) def force_run(self, hosts, function, attempts = 1): """ Like priority_run(), but starts the task immediately even if that max_threads is exceeded. :type hosts: string|list(string)|Host|list(Host) :param hosts: A hostname or Host object, or a list of them. :type function: function :param function: The function to execute. :type attempts: int :param attempts: The number of attempts on failure. :rtype: object :return: An object representing the task. """ return self._run(hosts, function, self.workqueue.priority_enqueue, True, attempts) def enqueue(self, function, name = None, attempts = 1): """ Places the given function in the queue and calls it as soon as a thread is available. To pass additional arguments to the callback, use Python's functools.partial(). :type function: function :param function: The function to execute. :type name: string :param name: A name for the task. :type attempts: int :param attempts: The number of attempts on failure. :rtype: object :return: An object representing the task. """ self.total += 1 task = Task(self.workqueue) job_id = self.workqueue.enqueue(function, name, attempts) if job_id is not None: task.add_job_id(job_id) self._dbg(2, 'Function enqueued.') return task