1 # Copyright (c) 2019 Cisco and/or its affiliates.
2 # Licensed under the Apache License, Version 2.0 (the "License");
3 # you may not use this file except in compliance with the License.
4 # You may obtain a copy of the License at:
6 # http://www.apache.org/licenses/LICENSE-2.0
8 # Unless required by applicable law or agreed to in writing, software
9 # distributed under the License is distributed on an "AS IS" BASIS,
10 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 # See the License for the specific language governing permissions and
12 # limitations under the License.
14 """Python API executor library.
27 from pprint import pformat
28 from robot.api import logger
30 from resources.libraries.python.Constants import Constants
31 from resources.libraries.python.LocalExecution import run
32 from resources.libraries.python.FilteredLogger import FilteredLogger
33 from resources.libraries.python.PythonThree import raise_from
34 from resources.libraries.python.PapiHistory import PapiHistory
35 from resources.libraries.python.ssh import (
36 SSH, SSHTimeout, exec_cmd_no_error, scp_node)
37 from resources.libraries.python.VppApiCrc import VppApiCrcChecker
40 __all__ = ["PapiExecutor", "PapiSocketExecutor"]
44 """A helper method, to make namedtuple-like object accessible as dict.
46 If the object is namedtuple-like, its _asdict() form is returned,
47 but in the returned object __getitem__ method is wrapped
48 to dictize also any items returned.
49 If the object does not have _asdict, it will be returned without any change.
50 Integer keys still access the object as tuple.
52 A more useful version would be to keep obj mostly as a namedtuple,
53 just add getitem for string keys. Unfortunately, namedtuple inherits
54 from tuple, including its read-only __getitem__ attribute,
55 so we cannot monkey-patch it.
57 TODO: Create a proxy for namedtuple to allow that.
59 :param obj: Arbitrary object to dictize.
61 :returns: Dictized object.
62 :rtype: same as obj type or collections.OrderedDict
64 if not hasattr(obj, "_asdict"):
67 old_get = ret.__getitem__
68 new_get = lambda self, key: dictize(old_get(self, key))
69 ret.__getitem__ = new_get
73 class PapiSocketExecutor(object):
74 """Methods for executing VPP Python API commands on forwarded socket.
76 The current implementation connects for the duration of resource manager.
77 Delay for accepting connection is 10s, and disconnect is explicit.
78 TODO: Decrease 10s to value that is long enough for creating connection
79 and short enough to not affect performance.
81 The current implementation downloads and parses .api.json files only once
82 and stores a VPPApiClient instance (disconnected) as a class variable.
83 Accessing multiple nodes with different APIs is therefore not supported.
85 The current implementation seems to run into read error occasionally.
86 Not sure if the error is in Python code on Robot side, ssh forwarding,
87 or socket handling at VPP side. Anyway, reconnect after some sleep
88 seems to help, hoping repeated command execution does not lead to surprises.
89 The reconnection is logged at WARN level, so it is prominently shown
90 in log.html, so we can see how frequently it happens.
92 TODO: Support sockets in NFs somehow.
93 TODO: Support handling of retval!=0 without try/except in caller.
95 Note: Use only with "with" statement, e.g.:
97 with PapiSocketExecutor(node) as papi_exec:
98 reply = papi_exec.add('show_version').get_reply(err_msg)
100 This class processes two classes of VPP PAPI methods:
101 1. Simple request / reply: method='request'.
102 2. Dump functions: method='dump'.
104 Note that access to VPP stats over socket is not supported yet.
106 The recommended ways of use are (examples):
108 1. Simple request / reply
110 a. One request with no arguments:
112 with PapiSocketExecutor(node) as papi_exec:
113 reply = papi_exec.add('show_version').get_reply(err_msg)
115 b. Three requests with arguments, the second and the third ones are the same
116 but with different arguments.
118 with PapiSocketExecutor(node) as papi_exec:
119 replies = papi_exec.add(cmd1, **args1).add(cmd2, **args2).\
120 add(cmd2, **args3).get_replies(err_msg)
124 cmd = 'sw_interface_rx_placement_dump'
125 with PapiSocketExecutor(node) as papi_exec:
126 details = papi_exec.add(cmd, sw_if_index=ifc['vpp_sw_index']).\
130 # Class cache for reuse between instances.
131 cached_vpp_instance = None
132 api_json_directory = None
133 crc_checker_instance = None
135 def __init__(self, node, remote_vpp_socket=Constants.SOCKSVR_PATH):
136 """Store the given arguments, declare managed variables.
138 :param node: Node to connect to and forward unix domain socket from.
139 :param remote_vpp_socket: Path to remote socket to tunnel to.
141 :type remote_vpp_socket: str
144 self._remote_vpp_socket = remote_vpp_socket
145 # The list of PAPI commands to be executed on the node.
146 self._api_command_list = list()
147 # The following values are set on enter, reset on exit.
148 self._temp_dir = None
149 self._ssh_control_socket = None
150 self._local_vpp_socket = None
152 def create_crc_checker(self):
153 """Return the cached instance or create new one from directory.
155 It is assumed self.api_json_directory is set, as a class variable.
157 :returns: Cached or newly created instance aware of .api.json content.
158 :rtype: VppApiCrc.VppApiCrcChecker
161 if cls.crc_checker_instance is None:
162 cls.crc_checker_instance = VppApiCrcChecker(cls.api_json_directory)
163 return cls.crc_checker_instance
166 def vpp_instance(self):
167 """Return VPP instance with bindings to all API calls.
169 The returned instance is initialized for unix domain socket access,
170 it has initialized all the bindings, but it is not connected
171 (to local socket) yet.
173 First invocation downloads .api.json files from self._node
174 into a temporary directory.
176 After first invocation, the result is cached, so other calls are quick.
177 Class variable is used as the cache, but this property is defined as
178 an instance method, so that _node (for api files) is known.
180 :returns: Initialized but not connected VPP instance.
181 :rtype: vpp_papi.VPPApiClient
184 if cls.cached_vpp_instance is not None:
185 return cls.cached_vpp_instance
186 tmp_dir = tempfile.mkdtemp(dir="/tmp")
187 package_path = "Not set yet."
189 # Pack, copy and unpack Python part of VPP installation from _node.
190 # TODO: Use rsync or recursive version of ssh.scp_node instead?
192 exec_cmd_no_error(node, ["rm", "-rf", "/tmp/papi.txz"])
193 # Papi python version depends on OS (and time).
194 # Python 2.7 or 3.4, site-packages or dist-packages.
195 installed_papi_glob = "/usr/lib/python*/*-packages/vpp_papi"
196 # We need to wrap this command in bash, in order to expand globs,
197 # and as ssh does join, the inner command has to be quoted.
198 inner_cmd = " ".join([
199 "tar", "cJf", "/tmp/papi.txz", "--exclude=*.pyc",
200 installed_papi_glob, "/usr/share/vpp/api"])
201 exec_cmd_no_error(node, ["bash", "-c", "'" + inner_cmd + "'"])
202 scp_node(node, tmp_dir + "/papi.txz", "/tmp/papi.txz", get=True)
203 run(["tar", "xf", tmp_dir + "/papi.txz", "-C", tmp_dir])
204 cls.api_json_directory = tmp_dir + "/usr/share/vpp/api"
205 # Perform initial checks before .api.json files are gone,
206 # by accessing the property (which also creates its instance).
207 self.create_crc_checker()
208 # When present locally, we finally can find the installation path.
209 package_path = glob.glob(tmp_dir + installed_papi_glob)[0]
210 # Package path has to be one level above the vpp_papi directory.
211 package_path = package_path.rsplit('/', 1)[0]
212 sys.path.append(package_path)
213 from vpp_papi.vpp_papi import VPPApiClient as vpp_class
214 vpp_class.apidir = cls.api_json_directory
215 # We need to create instance before removing from sys.path.
216 cls.cached_vpp_instance = vpp_class(
217 use_socket=True, server_address="TBD", async_thread=False,
218 read_timeout=14, logger=FilteredLogger(logger, "INFO"))
219 # Cannot use loglevel parameter, robot.api.logger lacks support.
220 # TODO: Stop overriding read_timeout when VPP-1722 is fixed.
222 shutil.rmtree(tmp_dir)
223 if sys.path[-1] == package_path:
225 return cls.cached_vpp_instance
228 """Create a tunnel, connect VPP instance.
230 Only at this point a local socket names are created
231 in a temporary directory, because VIRL runs 3 pybots at once,
232 so harcoding local filenames does not work.
235 :rtype: PapiSocketExecutor
237 # Parsing takes longer than connecting, prepare instance before tunnel.
238 vpp_instance = self.vpp_instance
240 self._temp_dir = tempfile.mkdtemp(dir="/tmp")
241 self._local_vpp_socket = self._temp_dir + "/vpp-api.sock"
242 self._ssh_control_socket = self._temp_dir + "/ssh.sock"
243 ssh_socket = self._ssh_control_socket
244 # Cleanup possibilities.
245 ret_code, _ = run(["ls", ssh_socket], check=False)
247 # This branch never seems to be hit in CI,
248 # but may be useful when testing manually.
249 run(["ssh", "-S", ssh_socket, "-O", "exit", "0.0.0.0"],
250 check=False, log=True)
251 # TODO: Is any sleep necessary? How to prove if not?
252 run(["sleep", "0.1"])
253 run(["rm", "-vrf", ssh_socket])
254 # Even if ssh can perhaps reuse this file,
255 # we need to remove it for readiness detection to work correctly.
256 run(["rm", "-rvf", self._local_vpp_socket])
257 # On VIRL, the ssh user is not added to "vpp" group,
258 # so we need to change remote socket file access rights.
260 node, "chmod o+rwx " + self._remote_vpp_socket, sudo=True)
261 # We use sleep command. The ssh command will exit in 10 second,
262 # unless a local socket connection is established,
263 # in which case the ssh command will exit only when
264 # the ssh connection is closed again (via control socket).
265 # The log level is to supress "Warning: Permanently added" messages.
267 "ssh", "-S", ssh_socket, "-M",
268 "-o", "LogLevel=ERROR", "-o", "UserKnownHostsFile=/dev/null",
269 "-o", "StrictHostKeyChecking=no", "-o", "ExitOnForwardFailure=yes",
270 "-L", self._local_vpp_socket + ':' + self._remote_vpp_socket,
271 "-p", str(node['port']), node['username'] + "@" + node['host'],
273 priv_key = node.get("priv_key")
275 # This is tricky. We need a file to pass the value to ssh command.
276 # And we need ssh command, because paramiko does not suport sockets
277 # (neither ssh_socket, nor _remote_vpp_socket).
278 key_file = tempfile.NamedTemporaryFile()
279 key_file.write(priv_key)
280 # Make sure the content is written, but do not close yet.
282 ssh_cmd[1:1] = ["-i", key_file.name]
283 password = node.get("password")
285 # Prepend sshpass command to set password.
286 ssh_cmd[:0] = ["sshpass", "-p", password]
287 time_stop = time.time() + 10.0
288 # subprocess.Popen seems to be the best way to run commands
289 # on background. Other ways (shell=True with "&" and ssh with -f)
290 # seem to be too dependent on shell behavior.
291 # In particular, -f does NOT return values for run().
292 subprocess.Popen(ssh_cmd)
293 # Check socket presence on local side.
294 while time.time() < time_stop:
295 # It can take a moment for ssh to create the socket file.
296 ret_code, _ = run(["ls", "-l", self._local_vpp_socket], check=False)
301 raise RuntimeError("Local side socket has not appeared.")
303 # Socket up means the key has been read. Delete file by closing it.
305 # Everything is ready, set the local socket address and connect.
306 vpp_instance.transport.server_address = self._local_vpp_socket
307 # It seems we can get read error even if every preceding check passed.
308 # Single retry seems to help.
311 vpp_instance.connect_sync("csit_socket")
312 except IOError as err:
313 logger.warn("Got initial connect error {err!r}".format(err=err))
314 vpp_instance.disconnect()
318 raise RuntimeError("Failed to connect to VPP over a socket.")
321 def __exit__(self, exc_type, exc_val, exc_tb):
322 """Disconnect the vpp instance, tear down the SHH tunnel.
324 Also remove the local sockets by deleting the temporary directory.
325 Arguments related to possible exception are entirely ignored.
327 self.vpp_instance.disconnect()
328 run(["ssh", "-S", self._ssh_control_socket, "-O", "exit", "0.0.0.0"],
330 shutil.rmtree(self._temp_dir)
333 def add(self, csit_papi_command, history=True, **kwargs):
334 """Add next command to internal command list; return self.
336 Unless disabled, new entry to papi history is also added at this point.
337 The argument name 'csit_papi_command' must be unique enough as it cannot
338 be repeated in kwargs.
339 The kwargs dict is deep-copied, so it is safe to use the original
340 with partial modifications for subsequent commands.
342 Any pending conflicts from .api.json processing are raised.
343 Then the command name is checked for known CRCs.
344 Unsupported commands raise an exception, as CSIT change
345 should not start using messages without making sure which CRCs
347 Each CRC issue is raised only once, so subsequent tests
348 can raise other issues.
350 :param csit_papi_command: VPP API command.
351 :param history: Enable/disable adding command to PAPI command history.
352 :param kwargs: Optional key-value arguments.
353 :type csit_papi_command: str
356 :returns: self, so that method chaining is possible.
357 :rtype: PapiSocketExecutor
358 :raises RuntimeError: If unverified or conflicting CRC is encountered.
361 PapiHistory.add_to_papi_history(
362 self._node, csit_papi_command, **kwargs)
363 self._api_command_list.append(
364 dict(api_name=csit_papi_command, api_args=copy.deepcopy(kwargs)))
367 def get_replies(self, err_msg="Failed to get replies."):
368 """Get replies from VPP Python API.
370 The replies are parsed into dict-like objects,
371 "retval" field is guaranteed to be zero on success.
373 :param err_msg: The message used if the PAPI command(s) execution fails.
375 :returns: Responses, dict objects with fields due to API and "retval".
377 :raises RuntimeError: If retval is nonzero, parsing or ssh error.
379 return self._execute(err_msg=err_msg)
381 def get_reply(self, err_msg="Failed to get reply."):
382 """Get reply from VPP Python API.
384 The reply is parsed into dict-like object,
385 "retval" field is guaranteed to be zero on success.
387 TODO: Discuss exception types to raise, unify with inner methods.
389 :param err_msg: The message used if the PAPI command(s) execution fails.
391 :returns: Response, dict object with fields due to API and "retval".
393 :raises AssertionError: If retval is nonzero, parsing or ssh error.
395 replies = self.get_replies(err_msg=err_msg)
396 if len(replies) != 1:
397 raise RuntimeError("Expected single reply, got {replies!r}".format(
401 def get_sw_if_index(self, err_msg="Failed to get reply."):
402 """Get sw_if_index from reply from VPP Python API.
404 Frequently, the caller is only interested in sw_if_index field
405 of the reply, this wrapper makes such call sites shorter.
407 TODO: Discuss exception types to raise, unify with inner methods.
409 :param err_msg: The message used if the PAPI command(s) execution fails.
411 :returns: Response, sw_if_index value of the reply.
413 :raises AssertionError: If retval is nonzero, parsing or ssh error.
415 reply = self.get_reply(err_msg=err_msg)
416 logger.info("Getting index from {reply!r}".format(reply=reply))
417 return reply["sw_if_index"]
419 def get_details(self, err_msg="Failed to get dump details."):
420 """Get dump details from VPP Python API.
422 The details are parsed into dict-like objects.
423 The number of details per single dump command can vary,
424 and all association between details and dumps is lost,
425 so if you care about the association (as opposed to
426 logging everything at once for debugging purposes),
427 it is recommended to call get_details for each dump (type) separately.
429 :param err_msg: The message used if the PAPI command(s) execution fails.
431 :returns: Details, dict objects with fields due to API without "retval".
434 return self._execute(err_msg)
437 def run_cli_cmd(node, cmd, log=True):
438 """Run a CLI command as cli_inband, return the "reply" field of reply.
440 Optionally, log the field value.
442 :param node: Node to run command on.
443 :param cmd: The CLI command to be run on the node.
444 :param log: If True, the response is logged.
448 :returns: CLI output.
453 err_msg = "Failed to run 'cli_inband {cmd}' PAPI command on host " \
454 "{host}".format(host=node['host'], cmd=cmd)
455 with PapiSocketExecutor(node) as papi_exec:
456 reply = papi_exec.add(cli, **args).get_reply(err_msg)["reply"]
458 logger.info("{cmd}:\n{reply}".format(cmd=cmd, reply=reply))
462 def dump_and_log(node, cmds):
463 """Dump and log requested information, return None.
465 :param node: DUT node.
466 :param cmds: Dump commands to be executed.
468 :type cmds: list of str
470 with PapiSocketExecutor(node) as papi_exec:
472 dump = papi_exec.add(cmd).get_details()
473 logger.debug("{cmd}:\n{data}".format(
474 cmd=cmd, data=pformat(dump)))
476 def _execute(self, err_msg="Undefined error message"):
477 """Turn internal command list into data and execute; return replies.
479 This method also clears the internal command list.
482 Do not use this method in L1 keywords. Use:
488 :param err_msg: The message used if the PAPI command(s) execution fails.
490 :returns: Papi responses parsed into a dict-like object,
491 with fields due to API (possibly including retval).
493 :raises RuntimeError: If the replies are not all correct.
495 vpp_instance = self.vpp_instance
496 local_list = self._api_command_list
497 # Clear first as execution may fail.
498 self._api_command_list = list()
500 for command in local_list:
501 api_name = command["api_name"]
502 papi_fn = getattr(vpp_instance.api, api_name)
505 reply = papi_fn(**command["api_args"])
506 except IOError as err:
507 # Ocassionally an error happens, try reconnect.
508 logger.warn("Reconnect after error: {err!r}".format(
510 self.vpp_instance.disconnect()
511 # Testing showes immediate reconnect fails.
513 self.vpp_instance.connect_sync("csit_socket")
514 logger.trace("Reconnected.")
515 reply = papi_fn(**command["api_args"])
516 except (AttributeError, IOError) as err:
517 raise_from(AssertionError(err_msg), err, level="INFO")
518 # *_dump commands return list of objects, convert, ordinary reply.
519 if not isinstance(reply, list):
522 dict_item = dictize(item)
523 if "retval" in dict_item.keys():
524 # *_details messages do not contain retval.
525 retval = dict_item["retval"]
527 # TODO: What exactly to log and raise here?
528 err = AssertionError("Retval {rv!r}".format(rv=retval))
529 # Lowering log level, some retval!=0 calls are expected.
530 # TODO: Expose level argument so callers can decide?
531 raise_from(AssertionError(err_msg), err, level="DEBUG")
532 replies.append(dict_item)
536 class PapiExecutor(object):
537 """Contains methods for executing VPP Python API commands on DUTs.
539 TODO: Remove .add step, make get_stats accept paths directly.
541 This class processes only one type of VPP PAPI methods: vpp-stats.
543 The recommended ways of use are (examples):
545 path = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
546 with PapiExecutor(node) as papi_exec:
547 stats = papi_exec.add(api_name='vpp-stats', path=path).get_stats()
549 print('RX interface core 0, sw_if_index 0:\n{0}'.\
550 format(stats[0]['/if/rx'][0][0]))
555 path_2 = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
556 with PapiExecutor(node) as papi_exec:
557 stats = papi_exec.add('vpp-stats', path=path_1).\
558 add('vpp-stats', path=path_2).get_stats()
560 print('RX interface core 0, sw_if_index 0:\n{0}'.\
561 format(stats[1]['/if/rx'][0][0]))
563 Note: In this case, when PapiExecutor method 'add' is used:
564 - its parameter 'csit_papi_command' is used only to keep information
565 that vpp-stats are requested. It is not further processed but it is
566 included in the PAPI history this way:
567 vpp-stats(path=['^/if', '/err/ip4-input', '/sys/node/ip4-input'])
568 Always use csit_papi_command="vpp-stats" if the VPP PAPI method
570 - the second parameter must be 'path' as it is used by PapiExecutor
574 def __init__(self, node):
577 :param node: Node to run command(s) on.
581 # Node to run command(s) on.
584 # The list of PAPI commands to be executed on the node.
585 self._api_command_list = list()
591 self._ssh.connect(self._node)
593 raise RuntimeError("Cannot open SSH connection to host {host} to "
594 "execute PAPI command(s)".
595 format(host=self._node["host"]))
598 def __exit__(self, exc_type, exc_val, exc_tb):
599 self._ssh.disconnect(self._node)
601 def add(self, csit_papi_command="vpp-stats", history=True, **kwargs):
602 """Add next command to internal command list; return self.
604 The argument name 'csit_papi_command' must be unique enough as it cannot
605 be repeated in kwargs.
606 The kwargs dict is deep-copied, so it is safe to use the original
607 with partial modifications for subsequent commands.
609 :param csit_papi_command: VPP API command.
610 :param history: Enable/disable adding command to PAPI command history.
611 :param kwargs: Optional key-value arguments.
612 :type csit_papi_command: str
615 :returns: self, so that method chaining is possible.
619 PapiHistory.add_to_papi_history(
620 self._node, csit_papi_command, **kwargs)
621 self._api_command_list.append(dict(
622 api_name=csit_papi_command, api_args=copy.deepcopy(kwargs)))
625 def get_stats(self, err_msg="Failed to get statistics.", timeout=120):
626 """Get VPP Stats from VPP Python API.
628 :param err_msg: The message used if the PAPI command(s) execution fails.
629 :param timeout: Timeout in seconds.
632 :returns: Requested VPP statistics.
636 paths = [cmd['api_args']['path'] for cmd in self._api_command_list]
637 self._api_command_list = list()
639 stdout = self._execute_papi(
640 paths, method='stats', err_msg=err_msg, timeout=timeout)
642 return json.loads(stdout)
645 def _process_api_data(api_d):
646 """Process API data for smooth converting to JSON string.
648 Apply binascii.hexlify() method for string values.
650 :param api_d: List of APIs with their arguments.
652 :returns: List of APIs with arguments pre-processed for JSON.
656 def process_value(val):
659 :param val: Value to be processed.
661 :returns: Processed value.
662 :rtype: dict or str or int
664 if isinstance(val, dict):
665 for val_k, val_v in val.iteritems():
666 val[str(val_k)] = process_value(val_v)
668 elif isinstance(val, list):
669 for idx, val_l in enumerate(val):
670 val[idx] = process_value(val_l)
673 return binascii.hexlify(val) if isinstance(val, str) else val
675 api_data_processed = list()
677 api_args_processed = dict()
678 for a_k, a_v in api["api_args"].iteritems():
679 api_args_processed[str(a_k)] = process_value(a_v)
680 api_data_processed.append(dict(api_name=api["api_name"],
681 api_args=api_args_processed))
682 return api_data_processed
684 def _execute_papi(self, api_data, method='request', err_msg="",
686 """Execute PAPI command(s) on remote node and store the result.
688 :param api_data: List of APIs with their arguments.
689 :param method: VPP Python API method. Supported methods are: 'request',
691 :param err_msg: The message used if the PAPI command(s) execution fails.
692 :param timeout: Timeout in seconds.
697 :returns: Stdout from remote python utility, to be parsed by caller.
699 :raises SSHTimeout: If PAPI command(s) execution has timed out.
700 :raises RuntimeError: If PAPI executor failed due to another reason.
701 :raises AssertionError: If PAPI command(s) execution has failed.
705 raise RuntimeError("No API data provided.")
707 json_data = json.dumps(api_data) \
708 if method in ("stats", "stats_request") \
709 else json.dumps(self._process_api_data(api_data))
711 cmd = "{fw_dir}/{papi_provider} --method {method} --data '{json}'".\
713 fw_dir=Constants.REMOTE_FW_DIR, method=method, json=json_data,
714 papi_provider=Constants.RESOURCES_PAPI_PROVIDER)
716 ret_code, stdout, _ = self._ssh.exec_command_sudo(
717 cmd=cmd, timeout=timeout, log_stdout_err=False)
718 # TODO: Fail on non-empty stderr?
720 logger.error("PAPI command(s) execution timeout on host {host}:"
721 "\n{apis}".format(host=self._node["host"],
724 except Exception as exc:
725 raise_from(RuntimeError(
726 "PAPI command(s) execution on host {host} "
727 "failed: {apis}".format(
728 host=self._node["host"], apis=api_data)), exc)
730 raise AssertionError(err_msg)