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.
169 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 from vpp_papi.vpp_papi import VPPApiClient as vpp_class
197 vpp_class.apidir = api_json_directory
198 # We need to create instance before removing from sys.path.
199 cls.vpp_instance = vpp_class(
200 use_socket=True, server_address="TBD", async_thread=False,
201 read_timeout=14, logger=FilteredLogger(logger, "INFO"))
202 # Cannot use loglevel parameter, robot.api.logger lacks support.
203 # TODO: Stop overriding read_timeout when VPP-1722 is fixed.
205 shutil.rmtree(tmp_dir)
206 if sys.path[-1] == package_path:
210 """Create a tunnel, connect VPP instance.
212 Only at this point a local socket names are created
213 in a temporary directory, because VIRL runs 3 pybots at once,
214 so harcoding local filenames does not work.
217 :rtype: PapiSocketExecutor
219 # Parsing takes longer than connecting, prepare instance before tunnel.
220 vpp_instance = self.vpp_instance
222 self._temp_dir = tempfile.mkdtemp(dir="/tmp")
223 self._local_vpp_socket = self._temp_dir + "/vpp-api.sock"
224 self._ssh_control_socket = self._temp_dir + "/ssh.sock"
225 ssh_socket = self._ssh_control_socket
226 # Cleanup possibilities.
227 ret_code, _ = run(["ls", ssh_socket], check=False)
229 # This branch never seems to be hit in CI,
230 # but may be useful when testing manually.
231 run(["ssh", "-S", ssh_socket, "-O", "exit", "0.0.0.0"],
232 check=False, log=True)
233 # TODO: Is any sleep necessary? How to prove if not?
234 run(["sleep", "0.1"])
235 run(["rm", "-vrf", ssh_socket])
236 # Even if ssh can perhaps reuse this file,
237 # we need to remove it for readiness detection to work correctly.
238 run(["rm", "-rvf", self._local_vpp_socket])
239 # On VIRL, the ssh user is not added to "vpp" group,
240 # so we need to change remote socket file access rights.
242 node, "chmod o+rwx " + self._remote_vpp_socket, sudo=True)
243 # We use sleep command. The ssh command will exit in 10 second,
244 # unless a local socket connection is established,
245 # in which case the ssh command will exit only when
246 # the ssh connection is closed again (via control socket).
247 # The log level is to supress "Warning: Permanently added" messages.
249 "ssh", "-S", ssh_socket, "-M",
250 "-o", "LogLevel=ERROR", "-o", "UserKnownHostsFile=/dev/null",
251 "-o", "StrictHostKeyChecking=no", "-o", "ExitOnForwardFailure=yes",
252 "-L", self._local_vpp_socket + ':' + self._remote_vpp_socket,
253 "-p", str(node['port']), node['username'] + "@" + node['host'],
255 priv_key = node.get("priv_key")
257 # This is tricky. We need a file to pass the value to ssh command.
258 # And we need ssh command, because paramiko does not suport sockets
259 # (neither ssh_socket, nor _remote_vpp_socket).
260 key_file = tempfile.NamedTemporaryFile()
261 key_file.write(priv_key)
262 # Make sure the content is written, but do not close yet.
264 ssh_cmd[1:1] = ["-i", key_file.name]
265 password = node.get("password")
267 # Prepend sshpass command to set password.
268 ssh_cmd[:0] = ["sshpass", "-p", password]
269 time_stop = time.time() + 10.0
270 # subprocess.Popen seems to be the best way to run commands
271 # on background. Other ways (shell=True with "&" and ssh with -f)
272 # seem to be too dependent on shell behavior.
273 # In particular, -f does NOT return values for run().
274 subprocess.Popen(ssh_cmd)
275 # Check socket presence on local side.
276 while time.time() < time_stop:
277 # It can take a moment for ssh to create the socket file.
278 ret_code, _ = run(["ls", "-l", self._local_vpp_socket], check=False)
283 raise RuntimeError("Local side socket has not appeared.")
285 # Socket up means the key has been read. Delete file by closing it.
287 # Everything is ready, set the local socket address and connect.
288 vpp_instance.transport.server_address = self._local_vpp_socket
289 # It seems we can get read error even if every preceding check passed.
290 # Single retry seems to help.
293 vpp_instance.connect_sync("csit_socket")
294 except IOError as err:
295 logger.warn("Got initial connect error {err!r}".format(err=err))
296 vpp_instance.disconnect()
300 raise RuntimeError("Failed to connect to VPP over a socket.")
303 def __exit__(self, exc_type, exc_val, exc_tb):
304 """Disconnect the vpp instance, tear down the SHH tunnel.
306 Also remove the local sockets by deleting the temporary directory.
307 Arguments related to possible exception are entirely ignored.
309 self.vpp_instance.disconnect()
310 run(["ssh", "-S", self._ssh_control_socket, "-O", "exit", "0.0.0.0"],
312 shutil.rmtree(self._temp_dir)
314 def add(self, csit_papi_command, history=True, **kwargs):
315 """Add next command to internal command list; return self.
317 Unless disabled, new entry to papi history is also added at this point.
318 The argument name 'csit_papi_command' must be unique enough as it cannot
319 be repeated in kwargs.
320 The kwargs dict is deep-copied, so it is safe to use the original
321 with partial modifications for subsequent commands.
323 Any pending conflicts from .api.json processing are raised.
324 Then the command name is checked for known CRCs.
325 Unsupported commands raise an exception, as CSIT change
326 should not start using messages without making sure which CRCs
328 Each CRC issue is raised only once, so subsequent tests
329 can raise other issues.
331 :param csit_papi_command: VPP API command.
332 :param history: Enable/disable adding command to PAPI command history.
333 :param kwargs: Optional key-value arguments.
334 :type csit_papi_command: str
337 :returns: self, so that method chaining is possible.
338 :rtype: PapiSocketExecutor
339 :raises RuntimeError: If unverified or conflicting CRC is encountered.
341 self.crc_checker.report_initial_conflicts()
343 PapiHistory.add_to_papi_history(
344 self._node, csit_papi_command, **kwargs)
345 self.crc_checker.check_api_name(csit_papi_command)
346 self._api_command_list.append(
347 dict(api_name=csit_papi_command, api_args=copy.deepcopy(kwargs)))
350 def get_replies(self, err_msg="Failed to get replies."):
351 """Get replies from VPP Python API.
353 The replies are parsed into dict-like objects,
354 "retval" field is guaranteed to be zero on success.
356 :param err_msg: The message used if the PAPI command(s) execution fails.
358 :returns: Responses, dict objects with fields due to API and "retval".
360 :raises RuntimeError: If retval is nonzero, parsing or ssh error.
362 return self._execute(err_msg=err_msg)
364 def get_reply(self, err_msg="Failed to get reply."):
365 """Get reply from VPP Python API.
367 The reply is parsed into dict-like object,
368 "retval" field is guaranteed to be zero on success.
370 TODO: Discuss exception types to raise, unify with inner methods.
372 :param err_msg: The message used if the PAPI command(s) execution fails.
374 :returns: Response, dict object with fields due to API and "retval".
376 :raises AssertionError: If retval is nonzero, parsing or ssh error.
378 replies = self.get_replies(err_msg=err_msg)
379 if len(replies) != 1:
380 raise RuntimeError("Expected single reply, got {replies!r}".format(
384 def get_sw_if_index(self, err_msg="Failed to get reply."):
385 """Get sw_if_index from reply from VPP Python API.
387 Frequently, the caller is only interested in sw_if_index field
388 of the reply, this wrapper makes such call sites shorter.
390 TODO: Discuss exception types to raise, unify with inner methods.
392 :param err_msg: The message used if the PAPI command(s) execution fails.
394 :returns: Response, sw_if_index value of the reply.
396 :raises AssertionError: If retval is nonzero, parsing or ssh error.
398 reply = self.get_reply(err_msg=err_msg)
399 logger.info("Getting index from {reply!r}".format(reply=reply))
400 return reply["sw_if_index"]
402 def get_details(self, err_msg="Failed to get dump details."):
403 """Get dump details from VPP Python API.
405 The details are parsed into dict-like objects.
406 The number of details per single dump command can vary,
407 and all association between details and dumps is lost,
408 so if you care about the association (as opposed to
409 logging everything at once for debugging purposes),
410 it is recommended to call get_details for each dump (type) separately.
412 :param err_msg: The message used if the PAPI command(s) execution fails.
414 :returns: Details, dict objects with fields due to API without "retval".
417 return self._execute(err_msg)
420 def run_cli_cmd(node, cmd, log=True):
421 """Run a CLI command as cli_inband, return the "reply" field of reply.
423 Optionally, log the field value.
425 :param node: Node to run command on.
426 :param cmd: The CLI command to be run on the node.
427 :param log: If True, the response is logged.
431 :returns: CLI output.
436 err_msg = "Failed to run 'cli_inband {cmd}' PAPI command on host " \
437 "{host}".format(host=node['host'], cmd=cmd)
438 with PapiSocketExecutor(node) as papi_exec:
439 reply = papi_exec.add(cli, **args).get_reply(err_msg)["reply"]
441 logger.info("{cmd}:\n{reply}".format(cmd=cmd, reply=reply))
445 def dump_and_log(node, cmds):
446 """Dump and log requested information, return None.
448 :param node: DUT node.
449 :param cmds: Dump commands to be executed.
451 :type cmds: list of str
453 with PapiSocketExecutor(node) as papi_exec:
455 dump = papi_exec.add(cmd).get_details()
456 logger.debug("{cmd}:\n{data}".format(
457 cmd=cmd, data=pformat(dump)))
459 def _execute(self, err_msg="Undefined error message"):
460 """Turn internal command list into data and execute; return replies.
462 This method also clears the internal command list.
465 Do not use this method in L1 keywords. Use:
471 :param err_msg: The message used if the PAPI command(s) execution fails.
473 :returns: Papi responses parsed into a dict-like object,
474 with fields due to API (possibly including retval).
476 :raises RuntimeError: If the replies are not all correct.
478 vpp_instance = self.vpp_instance
479 local_list = self._api_command_list
480 # Clear first as execution may fail.
481 self._api_command_list = list()
483 for command in local_list:
484 api_name = command["api_name"]
485 papi_fn = getattr(vpp_instance.api, api_name)
488 reply = papi_fn(**command["api_args"])
489 except IOError as err:
490 # Ocassionally an error happens, try reconnect.
491 logger.warn("Reconnect after error: {err!r}".format(
493 self.vpp_instance.disconnect()
494 # Testing showes immediate reconnect fails.
496 self.vpp_instance.connect_sync("csit_socket")
497 logger.trace("Reconnected.")
498 reply = papi_fn(**command["api_args"])
499 except (AttributeError, IOError) as err:
500 raise_from(AssertionError(err_msg), err, level="INFO")
501 # *_dump commands return list of objects, convert, ordinary reply.
502 if not isinstance(reply, list):
505 self.crc_checker.check_api_name(item.__class__.__name__)
506 dict_item = dictize(item)
507 if "retval" in dict_item.keys():
508 # *_details messages do not contain retval.
509 retval = dict_item["retval"]
511 # TODO: What exactly to log and raise here?
512 err = AssertionError("Retval {rv!r}".format(rv=retval))
513 # Lowering log level, some retval!=0 calls are expected.
514 # TODO: Expose level argument so callers can decide?
515 raise_from(AssertionError(err_msg), err, level="DEBUG")
516 replies.append(dict_item)
520 class PapiExecutor(object):
521 """Contains methods for executing VPP Python API commands on DUTs.
523 TODO: Remove .add step, make get_stats accept paths directly.
525 This class processes only one type of VPP PAPI methods: vpp-stats.
527 The recommended ways of use are (examples):
529 path = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
530 with PapiExecutor(node) as papi_exec:
531 stats = papi_exec.add(api_name='vpp-stats', path=path).get_stats()
533 print('RX interface core 0, sw_if_index 0:\n{0}'.\
534 format(stats[0]['/if/rx'][0][0]))
539 path_2 = ['^/if', '/err/ip4-input', '/sys/node/ip4-input']
540 with PapiExecutor(node) as papi_exec:
541 stats = papi_exec.add('vpp-stats', path=path_1).\
542 add('vpp-stats', path=path_2).get_stats()
544 print('RX interface core 0, sw_if_index 0:\n{0}'.\
545 format(stats[1]['/if/rx'][0][0]))
547 Note: In this case, when PapiExecutor method 'add' is used:
548 - its parameter 'csit_papi_command' is used only to keep information
549 that vpp-stats are requested. It is not further processed but it is
550 included in the PAPI history this way:
551 vpp-stats(path=['^/if', '/err/ip4-input', '/sys/node/ip4-input'])
552 Always use csit_papi_command="vpp-stats" if the VPP PAPI method
554 - the second parameter must be 'path' as it is used by PapiExecutor
558 def __init__(self, node):
561 :param node: Node to run command(s) on.
565 # Node to run command(s) on.
568 # The list of PAPI commands to be executed on the node.
569 self._api_command_list = list()
575 self._ssh.connect(self._node)
577 raise RuntimeError("Cannot open SSH connection to host {host} to "
578 "execute PAPI command(s)".
579 format(host=self._node["host"]))
582 def __exit__(self, exc_type, exc_val, exc_tb):
583 self._ssh.disconnect(self._node)
585 def add(self, csit_papi_command="vpp-stats", history=True, **kwargs):
586 """Add next command to internal command list; return self.
588 The argument name 'csit_papi_command' must be unique enough as it cannot
589 be repeated in kwargs.
590 The kwargs dict is deep-copied, so it is safe to use the original
591 with partial modifications for subsequent commands.
593 :param csit_papi_command: VPP API command.
594 :param history: Enable/disable adding command to PAPI command history.
595 :param kwargs: Optional key-value arguments.
596 :type csit_papi_command: str
599 :returns: self, so that method chaining is possible.
603 PapiHistory.add_to_papi_history(
604 self._node, csit_papi_command, **kwargs)
605 self._api_command_list.append(dict(
606 api_name=csit_papi_command, api_args=copy.deepcopy(kwargs)))
609 def get_stats(self, err_msg="Failed to get statistics.", timeout=120):
610 """Get VPP Stats from VPP Python API.
612 :param err_msg: The message used if the PAPI command(s) execution fails.
613 :param timeout: Timeout in seconds.
616 :returns: Requested VPP statistics.
620 paths = [cmd['api_args']['path'] for cmd in self._api_command_list]
621 self._api_command_list = list()
623 stdout = self._execute_papi(
624 paths, method='stats', err_msg=err_msg, timeout=timeout)
626 return json.loads(stdout)
629 def _process_api_data(api_d):
630 """Process API data for smooth converting to JSON string.
632 Apply binascii.hexlify() method for string values.
634 :param api_d: List of APIs with their arguments.
636 :returns: List of APIs with arguments pre-processed for JSON.
640 def process_value(val):
643 :param val: Value to be processed.
645 :returns: Processed value.
646 :rtype: dict or str or int
648 if isinstance(val, dict):
649 for val_k, val_v in val.iteritems():
650 val[str(val_k)] = process_value(val_v)
652 elif isinstance(val, list):
653 for idx, val_l in enumerate(val):
654 val[idx] = process_value(val_l)
657 return binascii.hexlify(val) if isinstance(val, str) else val
659 api_data_processed = list()
661 api_args_processed = dict()
662 for a_k, a_v in api["api_args"].iteritems():
663 api_args_processed[str(a_k)] = process_value(a_v)
664 api_data_processed.append(dict(api_name=api["api_name"],
665 api_args=api_args_processed))
666 return api_data_processed
668 def _execute_papi(self, api_data, method='request', err_msg="",
670 """Execute PAPI command(s) on remote node and store the result.
672 :param api_data: List of APIs with their arguments.
673 :param method: VPP Python API method. Supported methods are: 'request',
675 :param err_msg: The message used if the PAPI command(s) execution fails.
676 :param timeout: Timeout in seconds.
681 :returns: Stdout from remote python utility, to be parsed by caller.
683 :raises SSHTimeout: If PAPI command(s) execution has timed out.
684 :raises RuntimeError: If PAPI executor failed due to another reason.
685 :raises AssertionError: If PAPI command(s) execution has failed.
689 raise RuntimeError("No API data provided.")
691 json_data = json.dumps(api_data) \
692 if method in ("stats", "stats_request") \
693 else json.dumps(self._process_api_data(api_data))
695 cmd = "{fw_dir}/{papi_provider} --method {method} --data '{json}'".\
697 fw_dir=Constants.REMOTE_FW_DIR, method=method, json=json_data,
698 papi_provider=Constants.RESOURCES_PAPI_PROVIDER)
700 ret_code, stdout, _ = self._ssh.exec_command_sudo(
701 cmd=cmd, timeout=timeout, log_stdout_err=False)
702 # TODO: Fail on non-empty stderr?
704 logger.error("PAPI command(s) execution timeout on host {host}:"
705 "\n{apis}".format(host=self._node["host"],
708 except Exception as exc:
709 raise_from(RuntimeError(
710 "PAPI command(s) execution on host {host} "
711 "failed: {apis}".format(
712 host=self._node["host"], apis=api_data)), exc)
714 raise AssertionError(err_msg)