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.
132 """Takes long time to create, stores all PAPI functions and types."""
134 """Accesses .api.json files at creation, caching allows deleting them."""
136 def __init__(self, node, remote_vpp_socket=Constants.SOCKSVR_PATH):
137 """Store the given arguments, declare managed variables.
139 :param node: Node to connect to and forward unix domain socket from.
140 :param remote_vpp_socket: Path to remote socket to tunnel to.
142 :type remote_vpp_socket: str
145 self._remote_vpp_socket = remote_vpp_socket
146 # The list of PAPI commands to be executed on the node.
147 self._api_command_list = list()
148 # The following values are set on enter, reset on exit.
149 self._temp_dir = None
150 self._ssh_control_socket = None
151 self._local_vpp_socket = None
152 self.initialize_vpp_instance()
154 def initialize_vpp_instance(self):
155 """Create VPP instance with bindings to API calls, store as class field.
157 No-op if the instance had been stored already.
159 The instance is initialized for unix domain socket access,
160 it has initialized all the bindings, but it is not connected
161 (to a local socket) yet.
163 This method downloads .api.json files from self._node
164 into a temporary directory, deletes them finally.
166 if self.vpp_instance:
168 cls = self.__class__ # Shorthand for setting class fields.
170 tmp_dir = tempfile.mkdtemp(dir="/tmp")
172 # Pack, copy and unpack Python part of VPP installation from _node.
173 # TODO: Use rsync or recursive version of ssh.scp_node instead?
175 exec_cmd_no_error(node, ["rm", "-rf", "/tmp/papi.txz"])
176 # Papi python version depends on OS (and time).
177 # Python 2.7 or 3.4, site-packages or dist-packages.
178 installed_papi_glob = "/usr/lib/python*/*-packages/vpp_papi"
179 # We need to wrap this command in bash, in order to expand globs,
180 # and as ssh does join, the inner command has to be quoted.
181 inner_cmd = " ".join([
182 "tar", "cJf", "/tmp/papi.txz", "--exclude=*.pyc",
183 installed_papi_glob, "/usr/share/vpp/api"])
184 exec_cmd_no_error(node, ["bash", "-c", "'" + inner_cmd + "'"])
185 scp_node(node, tmp_dir + "/papi.txz", "/tmp/papi.txz", get=True)
186 run(["tar", "xf", tmp_dir + "/papi.txz", "-C", tmp_dir])
187 api_json_directory = tmp_dir + "/usr/share/vpp/api"
188 # Perform initial checks before .api.json files are gone,
189 # by creating the checker instance.
190 cls.crc_checker = VppApiCrcChecker(api_json_directory)
191 # When present locally, we finally can find the installation path.
192 package_path = glob.glob(tmp_dir + installed_papi_glob)[0]
193 # Package path has to be one level above the vpp_papi directory.
194 package_path = package_path.rsplit('/', 1)[0]
195 sys.path.append(package_path)
196 # pylint: disable=import-error
197 from vpp_papi.vpp_papi import VPPApiClient as vpp_class
198 vpp_class.apidir = api_json_directory
199 # We need to create instance before removing from sys.path.
200 cls.vpp_instance = vpp_class(
201 use_socket=True, server_address="TBD", async_thread=False,
202 read_timeout=14, logger=FilteredLogger(logger, "INFO"))
203 # Cannot use loglevel parameter, robot.api.logger lacks support.
204 # TODO: Stop overriding read_timeout when VPP-1722 is fixed.
206 shutil.rmtree(tmp_dir)
207 if sys.path[-1] == package_path:
211 """Create a tunnel, connect VPP instance.
213 Only at this point a local socket names are created
214 in a temporary directory, because VIRL runs 3 pybots at once,
215 so harcoding local filenames does not work.
218 :rtype: PapiSocketExecutor
220 # Parsing takes longer than connecting, prepare instance before tunnel.
221 vpp_instance = self.vpp_instance
223 self._temp_dir = tempfile.mkdtemp(dir="/tmp")
224 self._local_vpp_socket = self._temp_dir + "/vpp-api.sock"
225 self._ssh_control_socket = self._temp_dir + "/ssh.sock"
226 ssh_socket = self._ssh_control_socket
227 # Cleanup possibilities.
228 ret_code, _ = run(["ls", ssh_socket], check=False)
230 # This branch never seems to be hit in CI,
231 # but may be useful when testing manually.
232 run(["ssh", "-S", ssh_socket, "-O", "exit", "0.0.0.0"],
233 check=False, log=True)
234 # TODO: Is any sleep necessary? How to prove if not?
235 run(["sleep", "0.1"])
236 run(["rm", "-vrf", ssh_socket])
237 # Even if ssh can perhaps reuse this file,
238 # we need to remove it for readiness detection to work correctly.
239 run(["rm", "-rvf", self._local_vpp_socket])
240 # On VIRL, the ssh user is not added to "vpp" group,
241 # so we need to change remote socket file access rights.
243 node, "chmod o+rwx " + self._remote_vpp_socket, sudo=True)
244 # We use sleep command. The ssh command will exit in 10 second,
245 # unless a local socket connection is established,
246 # in which case the ssh command will exit only when
247 # the ssh connection is closed again (via control socket).
248 # The log level is to supress "Warning: Permanently added" messages.
250 "ssh", "-S", ssh_socket, "-M",
251 "-o", "LogLevel=ERROR", "-o", "UserKnownHostsFile=/dev/null",
252 "-o", "StrictHostKeyChecking=no", "-o", "ExitOnForwardFailure=yes",
253 "-L", self._local_vpp_socket + ':' + self._remote_vpp_socket,
254 "-p", str(node['port']), node['username'] + "@" + node['host'],
256 priv_key = node.get("priv_key")
258 # This is tricky. We need a file to pass the value to ssh command.
259 # And we need ssh command, because paramiko does not suport sockets
260 # (neither ssh_socket, nor _remote_vpp_socket).
261 key_file = tempfile.NamedTemporaryFile()
262 key_file.write(priv_key)
263 # Make sure the content is written, but do not close yet.
265 ssh_cmd[1:1] = ["-i", key_file.name]
266 password = node.get("password")
268 # Prepend sshpass command to set password.
269 ssh_cmd[:0] = ["sshpass", "-p", password]
270 time_stop = time.time() + 10.0
271 # subprocess.Popen seems to be the best way to run commands
272 # on background. Other ways (shell=True with "&" and ssh with -f)
273 # seem to be too dependent on shell behavior.
274 # In particular, -f does NOT return values for run().
275 subprocess.Popen(ssh_cmd)
276 # Check socket presence on local side.
277 while time.time() < time_stop:
278 # It can take a moment for ssh to create the socket file.
279 ret_code, _ = run(["ls", "-l", self._local_vpp_socket], check=False)
284 raise RuntimeError("Local side socket has not appeared.")
286 # Socket up means the key has been read. Delete file by closing it.
288 # Everything is ready, set the local socket address and connect.
289 vpp_instance.transport.server_address = self._local_vpp_socket
290 # It seems we can get read error even if every preceding check passed.
291 # Single retry seems to help.
294 vpp_instance.connect_sync("csit_socket")
295 except IOError as err:
296 logger.warn("Got initial connect error {err!r}".format(err=err))
297 vpp_instance.disconnect()
301 raise RuntimeError("Failed to connect to VPP over a socket.")
304 def __exit__(self, exc_type, exc_val, exc_tb):
305 """Disconnect the vpp instance, tear down the SHH tunnel.
307 Also remove the local sockets by deleting the temporary directory.
308 Arguments related to possible exception are entirely ignored.
310 self.vpp_instance.disconnect()
311 run(["ssh", "-S", self._ssh_control_socket, "-O", "exit", "0.0.0.0"],
313 shutil.rmtree(self._temp_dir)
315 def add(self, csit_papi_command, history=True, **kwargs):
316 """Add next command to internal command list; return self.
318 Unless disabled, new entry to papi history is also added at this point.
319 The argument name 'csit_papi_command' must be unique enough as it cannot
320 be repeated in kwargs.
321 The kwargs dict is deep-copied, so it is safe to use the original
322 with partial modifications for subsequent commands.
324 Any pending conflicts from .api.json processing are raised.
325 Then the command name is checked for known CRCs.
326 Unsupported commands raise an exception, as CSIT change
327 should not start using messages without making sure which CRCs
329 Each CRC issue is raised only once, so subsequent tests
330 can raise other issues.
332 :param csit_papi_command: VPP API command.
333 :param history: Enable/disable adding command to PAPI command history.
334 :param kwargs: Optional key-value arguments.
335 :type csit_papi_command: str
338 :returns: self, so that method chaining is possible.
339 :rtype: PapiSocketExecutor
340 :raises RuntimeError: If unverified or conflicting CRC is encountered.
342 self.crc_checker.report_initial_conflicts()
344 PapiHistory.add_to_papi_history(
345 self._node, csit_papi_command, **kwargs)
346 self.crc_checker.check_api_name(csit_papi_command)
347 self._api_command_list.append(
348 dict(api_name=csit_papi_command, api_args=copy.deepcopy(kwargs)))
351 def get_replies(self, err_msg="Failed to get replies."):
352 """Get replies from VPP Python API.
354 The replies are parsed into dict-like objects,
355 "retval" field is guaranteed to be zero on success.
357 :param err_msg: The message used if the PAPI command(s) execution fails.
359 :returns: Responses, dict objects with fields due to API and "retval".
361 :raises RuntimeError: If retval is nonzero, parsing or ssh error.
363 return self._execute(err_msg=err_msg)
365 def get_reply(self, err_msg="Failed to get reply."):
366 """Get reply from VPP Python API.
368 The reply is parsed into dict-like object,
369 "retval" field is guaranteed to be zero on success.
371 TODO: Discuss exception types to raise, unify with inner methods.
373 :param err_msg: The message used if the PAPI command(s) execution fails.
375 :returns: Response, dict object with fields due to API and "retval".
377 :raises AssertionError: If retval is nonzero, parsing or ssh error.
379 replies = self.get_replies(err_msg=err_msg)
380 if len(replies) != 1:
381 raise RuntimeError("Expected single reply, got {replies!r}".format(
385 def get_sw_if_index(self, err_msg="Failed to get reply."):
386 """Get sw_if_index from reply from VPP Python API.
388 Frequently, the caller is only interested in sw_if_index field
389 of the reply, this wrapper makes such call sites shorter.
391 TODO: Discuss exception types to raise, unify with inner methods.
393 :param err_msg: The message used if the PAPI command(s) execution fails.
395 :returns: Response, sw_if_index value of the reply.
397 :raises AssertionError: If retval is nonzero, parsing or ssh error.
399 reply = self.get_reply(err_msg=err_msg)
400 logger.info("Getting index from {reply!r}".format(reply=reply))
401 return reply["sw_if_index"]
403 def get_details(self, err_msg="Failed to get dump details."):
404 """Get dump details from VPP Python API.
406 The details are parsed into dict-like objects.
407 The number of details per single dump command can vary,
408 and all association between details and dumps is lost,
409 so if you care about the association (as opposed to
410 logging everything at once for debugging purposes),
411 it is recommended to call get_details for each dump (type) separately.
413 :param err_msg: The message used if the PAPI command(s) execution fails.
415 :returns: Details, dict objects with fields due to API without "retval".
418 return self._execute(err_msg)
421 def run_cli_cmd(node, cmd, log=True):
422 """Run a CLI command as cli_inband, return the "reply" field of reply.
424 Optionally, log the field value.
426 :param node: Node to run command on.
427 :param cmd: The CLI command to be run on the node.
428 :param log: If True, the response is logged.
432 :returns: CLI output.
437 err_msg = "Failed to run 'cli_inband {cmd}' PAPI command on host " \
438 "{host}".format(host=node['host'], cmd=cmd)
439 with PapiSocketExecutor(node) as papi_exec:
440 reply = papi_exec.add(cli, **args).get_reply(err_msg)["reply"]
442 logger.info("{cmd}:\n{reply}".format(cmd=cmd, reply=reply))
446 def dump_and_log(node, cmds):
447 """Dump and log requested information, return None.
449 :param node: DUT node.
450 :param cmds: Dump commands to be executed.
452 :type cmds: list of str
454 with PapiSocketExecutor(node) as papi_exec:
456 dump = papi_exec.add(cmd).get_details()
457 logger.debug("{cmd}:\n{data}".format(
458 cmd=cmd, data=pformat(dump)))
460 def _execute(self, err_msg="Undefined error message"):
461 """Turn internal command list into data and execute; return replies.
463 This method also clears the internal command list.
466 Do not use this method in L1 keywords. Use:
472 :param err_msg: The message used if the PAPI command(s) execution fails.
474 :returns: Papi responses parsed into a dict-like object,
475 with fields due to API (possibly including retval).
477 :raises RuntimeError: If the replies are not all correct.
479 vpp_instance = self.vpp_instance
480 local_list = self._api_command_list
481 # Clear first as execution may fail.
482 self._api_command_list = list()
484 for command in local_list:
485 api_name = command["api_name"]
486 papi_fn = getattr(vpp_instance.api, api_name)
489 reply = papi_fn(**command["api_args"])
490 except IOError as err:
491 # Ocassionally an error happens, try reconnect.
492 logger.warn("Reconnect after error: {err!r}".format(
494 self.vpp_instance.disconnect()
495 # Testing showes immediate reconnect fails.
497 self.vpp_instance.connect_sync("csit_socket")
498 logger.trace("Reconnected.")
499 reply = papi_fn(**command["api_args"])
500 except (AttributeError, IOError) as err:
501 raise_from(AssertionError(err_msg), err, level="INFO")
502 # *_dump commands return list of objects, convert, ordinary reply.
503 if not isinstance(reply, list):
506 self.crc_checker.check_api_name(item.__class__.__name__)
507 dict_item = dictize(item)
508 if "retval" in dict_item.keys():
509 # *_details messages do not contain retval.
510 retval = dict_item["retval"]
512 # TODO: What exactly to log and raise here?
513 err = AssertionError("Retval {rv!r}".format(rv=retval))
514 # Lowering log level, some retval!=0 calls are expected.
515 # TODO: Expose level argument so callers can decide?
516 raise_from(AssertionError(err_msg), err, level="DEBUG")
517 replies.append(dict_item)
521 class PapiExecutor(object):
522 """Contains methods for executing VPP Python API commands on DUTs.
524 TODO: Remove .add step, make get_stats accept paths directly.
526 This class processes only one type of VPP PAPI methods: vpp-stats.
528 The recommended ways of use are (examples):
530 path = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
531 with PapiExecutor(node) as papi_exec:
532 stats = papi_exec.add(api_name='vpp-stats', path=path).get_stats()
534 print('RX interface core 0, sw_if_index 0:\n{0}'.\
535 format(stats[0]['/if/rx'][0][0]))
540 path_2 = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
541 with PapiExecutor(node) as papi_exec:
542 stats = papi_exec.add('vpp-stats', path=path_1).\
543 add('vpp-stats', path=path_2).get_stats()
545 print('RX interface core 0, sw_if_index 0:\n{0}'.\
546 format(stats[1]['/if/rx'][0][0]))
548 Note: In this case, when PapiExecutor method 'add' is used:
549 - its parameter 'csit_papi_command' is used only to keep information
550 that vpp-stats are requested. It is not further processed but it is
551 included in the PAPI history this way:
552 vpp-stats(path=['^/if', '/err/ip4-input', '/sys/node/ip4-input'])
553 Always use csit_papi_command="vpp-stats" if the VPP PAPI method
555 - the second parameter must be 'path' as it is used by PapiExecutor
559 def __init__(self, node):
562 :param node: Node to run command(s) on.
566 # Node to run command(s) on.
569 # The list of PAPI commands to be executed on the node.
570 self._api_command_list = list()
576 self._ssh.connect(self._node)
578 raise RuntimeError("Cannot open SSH connection to host {host} to "
579 "execute PAPI command(s)".
580 format(host=self._node["host"]))
583 def __exit__(self, exc_type, exc_val, exc_tb):
584 self._ssh.disconnect(self._node)
586 def add(self, csit_papi_command="vpp-stats", history=True, **kwargs):
587 """Add next command to internal command list; return self.
589 The argument name 'csit_papi_command' must be unique enough as it cannot
590 be repeated in kwargs.
591 The kwargs dict is deep-copied, so it is safe to use the original
592 with partial modifications for subsequent commands.
594 :param csit_papi_command: VPP API command.
595 :param history: Enable/disable adding command to PAPI command history.
596 :param kwargs: Optional key-value arguments.
597 :type csit_papi_command: str
600 :returns: self, so that method chaining is possible.
604 PapiHistory.add_to_papi_history(
605 self._node, csit_papi_command, **kwargs)
606 self._api_command_list.append(dict(
607 api_name=csit_papi_command, api_args=copy.deepcopy(kwargs)))
610 def get_stats(self, err_msg="Failed to get statistics.", timeout=120):
611 """Get VPP Stats from VPP Python API.
613 :param err_msg: The message used if the PAPI command(s) execution fails.
614 :param timeout: Timeout in seconds.
617 :returns: Requested VPP statistics.
621 paths = [cmd['api_args']['path'] for cmd in self._api_command_list]
622 self._api_command_list = list()
624 stdout = self._execute_papi(
625 paths, method='stats', err_msg=err_msg, timeout=timeout)
627 return json.loads(stdout)
630 def _process_api_data(api_d):
631 """Process API data for smooth converting to JSON string.
633 Apply binascii.hexlify() method for string values.
635 :param api_d: List of APIs with their arguments.
637 :returns: List of APIs with arguments pre-processed for JSON.
641 def process_value(val):
644 :param val: Value to be processed.
646 :returns: Processed value.
647 :rtype: dict or str or int
649 if isinstance(val, dict):
650 for val_k, val_v in val.iteritems():
651 val[str(val_k)] = process_value(val_v)
653 elif isinstance(val, list):
654 for idx, val_l in enumerate(val):
655 val[idx] = process_value(val_l)
658 return binascii.hexlify(val) if isinstance(val, str) else val
660 api_data_processed = list()
662 api_args_processed = dict()
663 for a_k, a_v in api["api_args"].iteritems():
664 api_args_processed[str(a_k)] = process_value(a_v)
665 api_data_processed.append(dict(api_name=api["api_name"],
666 api_args=api_args_processed))
667 return api_data_processed
669 def _execute_papi(self, api_data, method='request', err_msg="",
671 """Execute PAPI command(s) on remote node and store the result.
673 :param api_data: List of APIs with their arguments.
674 :param method: VPP Python API method. Supported methods are: 'request',
676 :param err_msg: The message used if the PAPI command(s) execution fails.
677 :param timeout: Timeout in seconds.
682 :returns: Stdout from remote python utility, to be parsed by caller.
684 :raises SSHTimeout: If PAPI command(s) execution has timed out.
685 :raises RuntimeError: If PAPI executor failed due to another reason.
686 :raises AssertionError: If PAPI command(s) execution has failed.
690 raise RuntimeError("No API data provided.")
692 json_data = json.dumps(api_data) \
693 if method in ("stats", "stats_request") \
694 else json.dumps(self._process_api_data(api_data))
696 cmd = "{fw_dir}/{papi_provider} --method {method} --data '{json}'".\
698 fw_dir=Constants.REMOTE_FW_DIR, method=method, json=json_data,
699 papi_provider=Constants.RESOURCES_PAPI_PROVIDER)
701 ret_code, stdout, _ = self._ssh.exec_command_sudo(
702 cmd=cmd, timeout=timeout, log_stdout_err=False)
703 # TODO: Fail on non-empty stderr?
705 logger.error("PAPI command(s) execution timeout on host {host}:"
706 "\n{apis}".format(host=self._node["host"],
709 except Exception as exc:
710 raise_from(RuntimeError(
711 "PAPI command(s) execution on host {host} "
712 "failed: {apis}".format(
713 host=self._node["host"], apis=api_data)), exc)
715 raise AssertionError(err_msg)