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.
26 from pprint import pformat
27 from robot.api import logger
29 from resources.libraries.python.Constants import Constants
30 from resources.libraries.python.LocalExecution import run
31 from resources.libraries.python.FilteredLogger import FilteredLogger
32 from resources.libraries.python.PythonThree import raise_from
33 from resources.libraries.python.PapiHistory import PapiHistory
34 from resources.libraries.python.ssh import (
35 SSH, SSHTimeout, exec_cmd_no_error, scp_node)
36 from resources.libraries.python.VppApiCrc import VppApiCrcChecker
39 __all__ = ["PapiExecutor", "PapiSocketExecutor"]
43 """A helper method, to make namedtuple-like object accessible as dict.
45 If the object is namedtuple-like, its _asdict() form is returned,
46 but in the returned object __getitem__ method is wrapped
47 to dictize also any items returned.
48 If the object does not have _asdict, it will be returned without any change.
49 Integer keys still access the object as tuple.
51 A more useful version would be to keep obj mostly as a namedtuple,
52 just add getitem for string keys. Unfortunately, namedtuple inherits
53 from tuple, including its read-only __getitem__ attribute,
54 so we cannot monkey-patch it.
56 TODO: Create a proxy for namedtuple to allow that.
58 :param obj: Arbitrary object to dictize.
60 :returns: Dictized object.
61 :rtype: same as obj type or collections.OrderedDict
63 if not hasattr(obj, "_asdict"):
66 old_get = ret.__getitem__
67 new_get = lambda self, key: dictize(old_get(self, key))
68 ret.__getitem__ = new_get
72 class PapiSocketExecutor(object):
73 """Methods for executing VPP Python API commands on forwarded socket.
75 The current implementation connects for the duration of resource manager.
76 Delay for accepting connection is 10s, and disconnect is explicit.
77 TODO: Decrease 10s to value that is long enough for creating connection
78 and short enough to not affect performance.
80 The current implementation downloads and parses .api.json files only once
81 and stores a VPPApiClient instance (disconnected) as a class variable.
82 Accessing multiple nodes with different APIs is therefore not supported.
84 The current implementation seems to run into read error occasionally.
85 Not sure if the error is in Python code on Robot side, ssh forwarding,
86 or socket handling at VPP side. Anyway, reconnect after some sleep
87 seems to help, hoping repeated command execution does not lead to surprises.
88 The reconnection is logged at WARN level, so it is prominently shown
89 in log.html, so we can see how frequently it happens.
91 TODO: Support sockets in NFs somehow.
92 TODO: Support handling of retval!=0 without try/except in caller.
94 Note: Use only with "with" statement, e.g.:
96 with PapiSocketExecutor(node) as papi_exec:
97 reply = papi_exec.add('show_version').get_reply(err_msg)
99 This class processes two classes of VPP PAPI methods:
100 1. Simple request / reply: method='request'.
101 2. Dump functions: method='dump'.
103 Note that access to VPP stats over socket is not supported yet.
105 The recommended ways of use are (examples):
107 1. Simple request / reply
109 a. One request with no arguments:
111 with PapiSocketExecutor(node) as papi_exec:
112 reply = papi_exec.add('show_version').get_reply(err_msg)
114 b. Three requests with arguments, the second and the third ones are the same
115 but with different arguments.
117 with PapiSocketExecutor(node) as papi_exec:
118 replies = papi_exec.add(cmd1, **args1).add(cmd2, **args2).\
119 add(cmd2, **args3).get_replies(err_msg)
123 cmd = 'sw_interface_rx_placement_dump'
124 with PapiSocketExecutor(node) as papi_exec:
125 details = papi_exec.add(cmd, sw_if_index=ifc['vpp_sw_index']).\
129 # Class cache for reuse between instances.
130 cached_vpp_instance = None
131 api_json_directory = None
132 crc_checker_instance = None
134 def __init__(self, node, remote_vpp_socket="/run/vpp-api.sock"):
135 """Store the given arguments, declare managed variables.
137 :param node: Node to connect to and forward unix domain socket from.
138 :param remote_vpp_socket: Path to remote socket to tunnel to.
140 :type remote_vpp_socket: str
143 self._remote_vpp_socket = remote_vpp_socket
144 # The list of PAPI commands to be executed on the node.
145 self._api_command_list = list()
146 # The following values are set on enter, reset on exit.
147 self._temp_dir = None
148 self._ssh_control_socket = None
149 self._local_vpp_socket = None
152 def 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).
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 The argument name 'csit_papi_command' must be unique enough as it cannot
337 be repeated in kwargs.
338 Unless disabled, new entry to papi history is also added at this point.
340 Any pending conflicts from .api.json processing are raised.
341 Then the command name is checked for known CRCs.
342 Unsupported commands raise an exception, as CSIT change
343 should not start using messages without making sure which CRCs
345 Each CRC issue is raised only once, so subsequent tests
346 can raise other issues.
348 :param csit_papi_command: VPP API command.
349 :param history: Enable/disable adding command to PAPI command history.
350 :param kwargs: Optional key-value arguments.
351 :type csit_papi_command: str
354 :returns: self, so that method chaining is possible.
355 :rtype: PapiSocketExecutor
356 :raises RuntimeError: If unverified or conflicting CRC is encountered.
359 PapiHistory.add_to_papi_history(
360 self._node, csit_papi_command, **kwargs)
361 self._api_command_list.append(
362 dict(api_name=csit_papi_command, api_args=kwargs))
365 def get_replies(self, err_msg="Failed to get replies."):
366 """Get replies from VPP Python API.
368 The replies are parsed into dict-like objects,
369 "retval" field is guaranteed to be zero on success.
371 :param err_msg: The message used if the PAPI command(s) execution fails.
373 :returns: Responses, dict objects with fields due to API and "retval".
375 :raises RuntimeError: If retval is nonzero, parsing or ssh error.
377 return self._execute(err_msg=err_msg)
379 def get_reply(self, err_msg="Failed to get reply."):
380 """Get reply from VPP Python API.
382 The reply is parsed into dict-like object,
383 "retval" field is guaranteed to be zero on success.
385 TODO: Discuss exception types to raise, unify with inner methods.
387 :param err_msg: The message used if the PAPI command(s) execution fails.
389 :returns: Response, dict object with fields due to API and "retval".
391 :raises AssertionError: If retval is nonzero, parsing or ssh error.
393 replies = self.get_replies(err_msg=err_msg)
394 if len(replies) != 1:
395 raise RuntimeError("Expected single reply, got {replies!r}".format(
399 def get_sw_if_index(self, err_msg="Failed to get reply."):
400 """Get sw_if_index from reply from VPP Python API.
402 Frequently, the caller is only interested in sw_if_index field
403 of the reply, this wrapper makes such call sites shorter.
405 TODO: Discuss exception types to raise, unify with inner methods.
407 :param err_msg: The message used if the PAPI command(s) execution fails.
409 :returns: Response, sw_if_index value of the reply.
411 :raises AssertionError: If retval is nonzero, parsing or ssh error.
413 reply = self.get_reply(err_msg=err_msg)
414 logger.info("Getting index from {reply!r}".format(reply=reply))
415 return reply["sw_if_index"]
417 def get_details(self, err_msg="Failed to get dump details."):
418 """Get dump details from VPP Python API.
420 The details are parsed into dict-like objects.
421 The number of details per single dump command can vary,
422 and all association between details and dumps is lost,
423 so if you care about the association (as opposed to
424 logging everything at once for debugging purposes),
425 it is recommended to call get_details for each dump (type) separately.
427 :param err_msg: The message used if the PAPI command(s) execution fails.
429 :returns: Details, dict objects with fields due to API without "retval".
432 return self._execute(err_msg)
435 def run_cli_cmd(node, cmd, log=True):
436 """Run a CLI command as cli_inband, return the "reply" field of reply.
438 Optionally, log the field value.
440 :param node: Node to run command on.
441 :param cmd: The CLI command to be run on the node.
442 :param log: If True, the response is logged.
446 :returns: CLI output.
451 err_msg = "Failed to run 'cli_inband {cmd}' PAPI command on host " \
452 "{host}".format(host=node['host'], cmd=cmd)
453 with PapiSocketExecutor(node) as papi_exec:
454 reply = papi_exec.add(cli, **args).get_reply(err_msg)["reply"]
456 logger.info("{cmd}:\n{reply}".format(cmd=cmd, reply=reply))
460 def dump_and_log(node, cmds):
461 """Dump and log requested information, return None.
463 :param node: DUT node.
464 :param cmds: Dump commands to be executed.
466 :type cmds: list of str
468 with PapiSocketExecutor(node) as papi_exec:
470 dump = papi_exec.add(cmd).get_details()
471 logger.debug("{cmd}:\n{data}".format(
472 cmd=cmd, data=pformat(dump)))
474 def _execute(self, err_msg="Undefined error message"):
475 """Turn internal command list into data and execute; return replies.
477 This method also clears the internal command list.
480 Do not use this method in L1 keywords. Use:
486 :param err_msg: The message used if the PAPI command(s) execution fails.
488 :returns: Papi responses parsed into a dict-like object,
489 with fields due to API (possibly including retval).
491 :raises RuntimeError: If the replies are not all correct.
493 vpp_instance = self.vpp_instance
494 local_list = self._api_command_list
495 # Clear first as execution may fail.
496 self._api_command_list = list()
498 for command in local_list:
499 api_name = command["api_name"]
500 papi_fn = getattr(vpp_instance.api, api_name)
503 reply = papi_fn(**command["api_args"])
504 except IOError as err:
505 # Ocassionally an error happens, try reconnect.
506 logger.warn("Reconnect after error: {err!r}".format(
508 self.vpp_instance.disconnect()
509 # Testing showes immediate reconnect fails.
511 self.vpp_instance.connect_sync("csit_socket")
512 logger.trace("Reconnected.")
513 reply = papi_fn(**command["api_args"])
514 except (AttributeError, IOError) as err:
515 raise_from(AssertionError(err_msg), err, level="INFO")
516 # *_dump commands return list of objects, convert, ordinary reply.
517 if not isinstance(reply, list):
520 dict_item = dictize(item)
521 if "retval" in dict_item.keys():
522 # *_details messages do not contain retval.
523 retval = dict_item["retval"]
525 # TODO: What exactly to log and raise here?
526 err = AssertionError("Retval {rv!r}".format(rv=retval))
527 # Lowering log level, some retval!=0 calls are expected.
528 # TODO: Expose level argument so callers can decide?
529 raise_from(AssertionError(err_msg), err, level="DEBUG")
530 replies.append(dict_item)
534 class PapiExecutor(object):
535 """Contains methods for executing VPP Python API commands on DUTs.
537 TODO: Remove .add step, make get_stats accept paths directly.
539 This class processes only one type of VPP PAPI methods: vpp-stats.
541 The recommended ways of use are (examples):
543 path = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
544 with PapiExecutor(node) as papi_exec:
545 stats = papi_exec.add(api_name='vpp-stats', path=path).get_stats()
547 print('RX interface core 0, sw_if_index 0:\n{0}'.\
548 format(stats[0]['/if/rx'][0][0]))
553 path_2 = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
554 with PapiExecutor(node) as papi_exec:
555 stats = papi_exec.add('vpp-stats', path=path_1).\
556 add('vpp-stats', path=path_2).get_stats()
558 print('RX interface core 0, sw_if_index 0:\n{0}'.\
559 format(stats[1]['/if/rx'][0][0]))
561 Note: In this case, when PapiExecutor method 'add' is used:
562 - its parameter 'csit_papi_command' is used only to keep information
563 that vpp-stats are requested. It is not further processed but it is
564 included in the PAPI history this way:
565 vpp-stats(path=['^/if', '/err/ip4-input', '/sys/node/ip4-input'])
566 Always use csit_papi_command="vpp-stats" if the VPP PAPI method
568 - the second parameter must be 'path' as it is used by PapiExecutor
572 def __init__(self, node):
575 :param node: Node to run command(s) on.
579 # Node to run command(s) on.
582 # The list of PAPI commands to be executed on the node.
583 self._api_command_list = list()
589 self._ssh.connect(self._node)
591 raise RuntimeError("Cannot open SSH connection to host {host} to "
592 "execute PAPI command(s)".
593 format(host=self._node["host"]))
596 def __exit__(self, exc_type, exc_val, exc_tb):
597 self._ssh.disconnect(self._node)
599 def add(self, csit_papi_command="vpp-stats", history=True, **kwargs):
600 """Add next command to internal command list; return self.
602 The argument name 'csit_papi_command' must be unique enough as it cannot
603 be repeated in kwargs.
605 :param csit_papi_command: VPP API command.
606 :param history: Enable/disable adding command to PAPI command history.
607 :param kwargs: Optional key-value arguments.
608 :type csit_papi_command: str
611 :returns: self, so that method chaining is possible.
615 PapiHistory.add_to_papi_history(
616 self._node, csit_papi_command, **kwargs)
617 self._api_command_list.append(dict(api_name=csit_papi_command,
621 def get_stats(self, err_msg="Failed to get statistics.", timeout=120):
622 """Get VPP Stats from VPP Python API.
624 :param err_msg: The message used if the PAPI command(s) execution fails.
625 :param timeout: Timeout in seconds.
628 :returns: Requested VPP statistics.
632 paths = [cmd['api_args']['path'] for cmd in self._api_command_list]
633 self._api_command_list = list()
635 stdout = self._execute_papi(
636 paths, method='stats', err_msg=err_msg, timeout=timeout)
638 return json.loads(stdout)
641 def _process_api_data(api_d):
642 """Process API data for smooth converting to JSON string.
644 Apply binascii.hexlify() method for string values.
646 :param api_d: List of APIs with their arguments.
648 :returns: List of APIs with arguments pre-processed for JSON.
652 def process_value(val):
655 :param val: Value to be processed.
657 :returns: Processed value.
658 :rtype: dict or str or int
660 if isinstance(val, dict):
661 for val_k, val_v in val.iteritems():
662 val[str(val_k)] = process_value(val_v)
664 elif isinstance(val, list):
665 for idx, val_l in enumerate(val):
666 val[idx] = process_value(val_l)
669 return binascii.hexlify(val) if isinstance(val, str) else val
671 api_data_processed = list()
673 api_args_processed = dict()
674 for a_k, a_v in api["api_args"].iteritems():
675 api_args_processed[str(a_k)] = process_value(a_v)
676 api_data_processed.append(dict(api_name=api["api_name"],
677 api_args=api_args_processed))
678 return api_data_processed
680 def _execute_papi(self, api_data, method='request', err_msg="",
682 """Execute PAPI command(s) on remote node and store the result.
684 :param api_data: List of APIs with their arguments.
685 :param method: VPP Python API method. Supported methods are: 'request',
687 :param err_msg: The message used if the PAPI command(s) execution fails.
688 :param timeout: Timeout in seconds.
693 :returns: Stdout from remote python utility, to be parsed by caller.
695 :raises SSHTimeout: If PAPI command(s) execution has timed out.
696 :raises RuntimeError: If PAPI executor failed due to another reason.
697 :raises AssertionError: If PAPI command(s) execution has failed.
701 raise RuntimeError("No API data provided.")
703 json_data = json.dumps(api_data) \
704 if method in ("stats", "stats_request") \
705 else json.dumps(self._process_api_data(api_data))
707 cmd = "{fw_dir}/{papi_provider} --method {method} --data '{json}'".\
709 fw_dir=Constants.REMOTE_FW_DIR, method=method, json=json_data,
710 papi_provider=Constants.RESOURCES_PAPI_PROVIDER)
712 ret_code, stdout, _ = self._ssh.exec_command_sudo(
713 cmd=cmd, timeout=timeout, log_stdout_err=False)
714 # TODO: Fail on non-empty stderr?
716 logger.error("PAPI command(s) execution timeout on host {host}:"
717 "\n{apis}".format(host=self._node["host"],
720 except Exception as exc:
721 raise_from(RuntimeError(
722 "PAPI command(s) execution on host {host} "
723 "failed: {apis}".format(
724 host=self._node["host"], apis=api_data)), exc)
726 raise AssertionError(err_msg)