diff options
Diffstat (limited to 'resources/libraries/python/PapiExecutor.py')
| -rw-r--r-- | resources/libraries/python/PapiExecutor.py | 430 |
1 files changed, 353 insertions, 77 deletions
diff --git a/resources/libraries/python/PapiExecutor.py b/resources/libraries/python/PapiExecutor.py index 46fe5d583b..6b21680526 100644 --- a/resources/libraries/python/PapiExecutor.py +++ b/resources/libraries/python/PapiExecutor.py @@ -37,7 +37,11 @@ from resources.libraries.python.topology import Topology, SocketType from resources.libraries.python.VppApiCrc import VppApiCrcChecker -__all__ = [u"PapiExecutor", u"PapiSocketExecutor"] +__all__ = [ + u"PapiExecutor", + u"PapiSocketExecutor", + u"Disconnector", +] def dictize(obj): @@ -73,14 +77,33 @@ def dictize(obj): class PapiSocketExecutor: """Methods for executing VPP Python API commands on forwarded socket. - The current implementation connects for the duration of resource manager. - Delay for accepting connection is 10s, and disconnect is explicit. + Previously, we used an implementation with single client instance + and connection being handled by a resource manager. + On "with" statement, the instance connected, and disconnected + on exit from the "with" block. + This was limiting (no nested with blocks) and mainly it was slow: + 0.7 seconds per disconnect cycle on Skylake, more than 3 second on Taishan. + + The currently used implementation caches the connected client instances, + providing speedup and making "with" blocks unnecessary. + But with many call sites, "with" blocks are still the main usage pattern. + Documentation still lists that as the intended pattern. + + As a downside, clients need to be explicitly told to disconnect + before VPP restart. + There is some amount of retries and disconnects on disconnect + (so unresponsive VPPs do not breach test much more than needed), + but it is hard to verify all that works correctly. + Especially, if Robot crashes, files and ssh processes may leak. + + Delay for accepting socket connection is 10s. TODO: Decrease 10s to value that is long enough for creating connection and short enough to not affect performance. The current implementation downloads and parses .api.json files only once - and stores a VPPApiClient instance (disconnected) as a class variable. - Accessing multiple nodes with different APIs is therefore not supported. + and caches client instances for reuse. + Cleanup metadata is added as additional attributes + directly to client instances. The current implementation seems to run into read error occasionally. Not sure if the error is in Python code on Robot side, ssh forwarding, @@ -129,10 +152,25 @@ class PapiSocketExecutor: """ # Class cache for reuse between instances. - vpp_instance = None - """Takes long time to create, stores all PAPI functions and types.""" + api_root_dir = None + """We copy .api json files and PAPI code from DUT to robot machine. + This class variable holds temporary directory once created. + When python exits, the directory is deleted, so no downloaded file leaks. + The value will be set to TemporaryDirectory class instance (not string path) + to ensure deletion at exit.""" + api_json_path = None + """String path to .api.json files, a directory somewhere in api_root_dir.""" + api_package_path = None + """String path to PAPI code, a different directory under api_root_dir.""" crc_checker = None - """Accesses .api.json files at creation, caching allows deleting them.""" + """Accesses .api.json files at creation, caching speeds up accessing it.""" + reusable_vpp_client_list = list() + """Each connection needs a separate client instance, + and each client instance creation needs to parse all .api files, + which takes time. If a client instance disconnects, it is put here, + so on next connect we can reuse intead of creating new.""" + conn_cache = dict() + """Mapping from node key to connected client instance.""" def __init__(self, node, remote_vpp_socket=Constants.SOCKSVR_PATH): """Store the given arguments, declare managed variables. @@ -146,89 +184,214 @@ class PapiSocketExecutor: self._remote_vpp_socket = remote_vpp_socket # The list of PAPI commands to be executed on the node. self._api_command_list = list() - # The following values are set on enter, reset on exit. - self._temp_dir = None - self._ssh_control_socket = None - self._local_vpp_socket = None - self.initialize_vpp_instance() - def initialize_vpp_instance(self): - """Create VPP instance with bindings to API calls, store as class field. + def ensure_api_dirs(self): + """Copy files from DUT to local temporary directory. - No-op if the instance had been stored already. + If the directory is still there, do not copy again. + If copying, also initialize CRC checker (this also performs + static checks), and remember PAPI package path. + Do not add that to PATH yet. + """ + cls = self.__class__ + if cls.api_package_path: + return + cls.api_root_dir = tempfile.TemporaryDirectory(dir=u"/tmp") + root_path = cls.api_root_dir.name + # Pack, copy and unpack Python part of VPP installation from _node. + # TODO: Use rsync or recursive version of ssh.scp_node instead? + node = self._node + exec_cmd_no_error(node, [u"rm", u"-rf", u"/tmp/papi.txz"]) + # Papi python version depends on OS (and time). + # Python 2.7 or 3.4, site-packages or dist-packages. + installed_papi_glob = u"/usr/lib/python3*/*-packages/vpp_papi" + # We need to wrap this command in bash, in order to expand globs, + # and as ssh does join, the inner command has to be quoted. + inner_cmd = u" ".join([ + u"tar", u"cJf", u"/tmp/papi.txz", u"--exclude=*.pyc", + installed_papi_glob, u"/usr/share/vpp/api" + ]) + exec_cmd_no_error(node, [u"bash", u"-c", u"'" + inner_cmd + u"'"]) + scp_node(node, root_path + u"/papi.txz", u"/tmp/papi.txz", get=True) + run([u"tar", u"xf", root_path + u"/papi.txz", u"-C", root_path]) + cls.api_json_path = root_path + u"/usr/share/vpp/api" + # Perform initial checks before .api.json files are gone, + # by creating the checker instance. + cls.crc_checker = VppApiCrcChecker(cls.api_json_path) + # When present locally, we finally can find the installation path. + cls.api_package_path = glob.glob(root_path + installed_papi_glob)[0] + # Package path has to be one level above the vpp_papi directory. + cls.api_package_path = cls.api_package_path.rsplit(u"/", 1)[0] + + def ensure_vpp_instance(self): + """Create or reuse a closed client instance, return it. The instance is initialized for unix domain socket access, - it has initialized all the bindings, but it is not connected + it has initialized all the bindings, it is removed from the internal + list of disconnected instances, but it is not connected (to a local socket) yet. - This method downloads .api.json files from self._node - into a temporary directory, deletes them finally. + :returns: VPP client instance ready for connect. + :rtype: vpp_papi.VPPApiClient """ - if self.vpp_instance: - return - cls = self.__class__ # Shorthand for setting class fields. - package_path = None - tmp_dir = tempfile.mkdtemp(dir=u"/tmp") + self.ensure_api_dirs() + cls = self.__class__ + if cls.reusable_vpp_client_list: + # Reuse in LIFO fashion. + *cls.reusable_vpp_client_list, ret = cls.reusable_vpp_client_list + return ret + # Creating an instance leads to dynamic imports from VPP PAPI code, + # so the package directory has to be present until the instance. + # But it is simpler to keep the package dir around. try: - # Pack, copy and unpack Python part of VPP installation from _node. - # TODO: Use rsync or recursive version of ssh.scp_node instead? - node = self._node - exec_cmd_no_error(node, [u"rm", u"-rf", u"/tmp/papi.txz"]) - # Papi python version depends on OS (and time). - # Python 2.7 or 3.4, site-packages or dist-packages. - installed_papi_glob = u"/usr/lib/python3*/*-packages/vpp_papi" - # We need to wrap this command in bash, in order to expand globs, - # and as ssh does join, the inner command has to be quoted. - inner_cmd = u" ".join([ - u"tar", u"cJf", u"/tmp/papi.txz", u"--exclude=*.pyc", - installed_papi_glob, u"/usr/share/vpp/api" - ]) - exec_cmd_no_error(node, [u"bash", u"-c", u"'" + inner_cmd + u"'"]) - scp_node(node, tmp_dir + u"/papi.txz", u"/tmp/papi.txz", get=True) - run([u"tar", u"xf", tmp_dir + u"/papi.txz", u"-C", tmp_dir]) - api_json_directory = tmp_dir + u"/usr/share/vpp/api" - # Perform initial checks before .api.json files are gone, - # by creating the checker instance. - cls.crc_checker = VppApiCrcChecker(api_json_directory) - # When present locally, we finally can find the installation path. - package_path = glob.glob(tmp_dir + installed_papi_glob)[0] - # Package path has to be one level above the vpp_papi directory. - package_path = package_path.rsplit(u"/", 1)[0] - sys.path.append(package_path) + sys.path.append(cls.api_package_path) # TODO: Pylint says import-outside-toplevel and import-error. # It is right, we should refactor the code and move initialization # of package outside. from vpp_papi.vpp_papi import VPPApiClient as vpp_class - vpp_class.apidir = api_json_directory + vpp_class.apidir = cls.api_json_path # We need to create instance before removing from sys.path. - cls.vpp_instance = vpp_class( + vpp_instance = vpp_class( use_socket=True, server_address=u"TBD", async_thread=False, - read_timeout=14, logger=FilteredLogger(logger, u"INFO")) + read_timeout=14, logger=FilteredLogger(logger, u"INFO") + ) # Cannot use loglevel parameter, robot.api.logger lacks support. # TODO: Stop overriding read_timeout when VPP-1722 is fixed. finally: - shutil.rmtree(tmp_dir) - if sys.path[-1] == package_path: + if sys.path[-1] == cls.api_package_path: sys.path.pop() + return vpp_instance + + @classmethod + def key_for_node_and_socket(cls, node, remote_socket): + """Return a hashable object to distinguish nodes. + + The usual node object (of "dict" type) is not hashable, + and can contain mutable information (mostly virtual interfaces). + Use this method to get an object suitable for being a key in dict. + + The fields to include are chosen by what ssh needs. + + This class method is needed, for disconnect. + + :param node: The node object to distinguish. + :param remote_socket: Path to remote socket. + :type node: dict + :type remote_socket: str + :return: Tuple of values distinguishing this node from similar ones. + :rtype: tuple of str + """ + return ( + node[u"host"], + node[u"port"], + remote_socket, + # TODO: Do we support sockets paths such as "~/vpp/api.socket"? + # If yes, add also: + # node[u"username"], + ) + + def key_for_self(self): + """Return a hashable object to distinguish nodes. + + Just a wrapper around key_for_node_and_socket + which sets up proper arguments. + + :return: Tuple of values distinguishing this node from similar ones. + :rtype: tuple of str + """ + return self.__class__.key_for_node_and_socket( + self._node, self._remote_vpp_socket, + ) + + def set_connected_client(self, client): + """Add a connected client instance into cache. + + This hides details of what the node key is. + + If there already is a client for the computed key, + fail, as it is a sign of resource leakage. + + :param client: VPP client instance in connected state. + :type client: vpp_papi.VPPApiClient + :raises RuntimeError: If related key already has a cached client. + """ + key = self.key_for_self() + cache = self.__class__.conn_cache + if key in cache: + raise RuntimeError(f"Caching client with existing key: {key}") + cache[key] = client + + def get_connected_client(self, check_connected=True): + """Return None or cached connected client. + + If check_connected, RuntimeError is raised when the client is + not in cache. None is returned if client is not in cache + (and the check is disabled). + + This hides details of what the node key is. + + :param check_connected: Whether cache miss raises. + :type check_connected: bool + :returns: Connected client instance, or None if uncached and no check. + :rtype: Optional[vpp_papi.VPPApiClient] + :raises RuntimeError: If cache miss and check enabled. + """ + key = self.key_for_self() + ret = self.__class__.conn_cache.get(key, None) + + if ret is None: + if check_connected: + raise RuntimeError(f"Client not cached for key: {key}") + else: + # When reading logs, it is good to see which VPP is accessed. + logger.debug(f"Activated cached PAPI client for key: {key}") + return ret def __enter__(self): """Create a tunnel, connect VPP instance. + If the connected client is in cache, return it. + Only if not, create a new (or reuse a disconnected) client instance. + Only at this point a local socket names are created - in a temporary directory, because VIRL runs 3 pybots at once, - so harcoding local filenames does not work. + in a temporary directory, as CSIT can connect to multiple VPPs. + + The following attributes are added to the client instance + to simplify caching and cleanup: + csit_temp_dir + - Temporary socket files are created here. + csit_control_socket + - This socket controls the local ssh process doing the forwarding. + csit_local_vpp_socket + - This is the forwarded socket to talk with remote VPP. + + The attribute names do not start with underscore, + so pylint does not complain about accessing private attribute. + The attribute names start with csit_ to avoid naming conflicts + with "real" attributes from VPP Python code. :returns: self :rtype: PapiSocketExecutor """ + # Do we have the connected instance in the cache? + vpp_instance = self.get_connected_client(check_connected=False) + if vpp_instance is not None: + return self + # No luck, create and connect a new instance. time_enter = time.time() - # Parsing takes longer than connecting, prepare instance before tunnel. - vpp_instance = self.vpp_instance node = self._node - self._temp_dir = tempfile.mkdtemp(dir=u"/tmp") - self._local_vpp_socket = self._temp_dir + u"/vpp-api.sock" - self._ssh_control_socket = self._temp_dir + u"/ssh.sock" - ssh_socket = self._ssh_control_socket + # Parsing takes longer than connecting, prepare instance before tunnel. + vpp_instance = self.ensure_vpp_instance() + # Store into cache as soon as possible. + # If connection fails, it is better to attempt disconnect anyway. + self.set_connected_client(vpp_instance) + # Set additional attributes. + vpp_instance.csit_temp_dir = tempfile.TemporaryDirectory(dir=u"/tmp") + temp_path = vpp_instance.csit_temp_dir.name + api_socket = temp_path + u"/vpp-api.sock" + vpp_instance.csit_local_vpp_socket = api_socket + ssh_socket = temp_path + u"/ssh.sock" + vpp_instance.csit_control_socket = ssh_socket # Cleanup possibilities. ret_code, _ = run([u"ls", ssh_socket], check=False) if ret_code != 2: @@ -243,19 +406,21 @@ class PapiSocketExecutor: run([u"rm", u"-vrf", ssh_socket]) # Even if ssh can perhaps reuse this file, # we need to remove it for readiness detection to work correctly. - run([u"rm", u"-rvf", self._local_vpp_socket]) + run([u"rm", u"-rvf", api_socket]) # We use sleep command. The ssh command will exit in 30 second, # unless a local socket connection is established, # in which case the ssh command will exit only when # the ssh connection is closed again (via control socket). # The log level is to suppress "Warning: Permanently added" messages. ssh_cmd = [ - u"ssh", u"-S", ssh_socket, u"-M", - u"-o", u"LogLevel=ERROR", u"-o", u"UserKnownHostsFile=/dev/null", + u"ssh", u"-S", ssh_socket, u"-M", u"-L", + api_socket + u":" + self._remote_vpp_socket, + u"-p", str(node[u"port"]), + u"-o", u"LogLevel=ERROR", + u"-o", u"UserKnownHostsFile=/dev/null", u"-o", u"StrictHostKeyChecking=no", u"-o", u"ExitOnForwardFailure=yes", - u"-L", self._local_vpp_socket + u":" + self._remote_vpp_socket, - u"-p", str(node[u"port"]), node[u"username"] + u"@" + node[u"host"], + node[u"username"] + u"@" + node[u"host"], u"sleep", u"30" ] priv_key = node.get(u"priv_key") @@ -282,7 +447,7 @@ class PapiSocketExecutor: while time.time() < time_stop: # It can take a moment for ssh to create the socket file. ret_code, _ = run( - [u"ls", u"-l", self._local_vpp_socket], check=False + [u"ls", u"-l", api_socket], check=False ) if not ret_code: break @@ -293,7 +458,7 @@ class PapiSocketExecutor: # Socket up means the key has been read. Delete file by closing it. key_file.close() # Everything is ready, set the local socket address and connect. - vpp_instance.transport.server_address = self._local_vpp_socket + vpp_instance.transport.server_address = api_socket # It seems we can get read error even if every preceding check passed. # Single retry seems to help. for _ in range(2): @@ -312,16 +477,100 @@ class PapiSocketExecutor: return self def __exit__(self, exc_type, exc_val, exc_tb): - """Disconnect the vpp instance, tear down the SHH tunnel. + """No-op, the client instance remains in cache in connected state.""" + + @classmethod + def disconnect_by_key(cls, key): + """Disconnect a connected client instance, noop it not connected. Also remove the local sockets by deleting the temporary directory. - Arguments related to possible exception are entirely ignored. + Put disconnected client instances to the reuse list. + The added attributes are not cleaned up, + as their values will get overwritten on next connect. + + This method is useful for disconnect_all type of work. + + :param key: Tuple identifying the node (and socket). + :type key: tuple of str """ - self.vpp_instance.disconnect() + client_instance = cls.conn_cache.get(key, None) + if client_instance is None: + return + logger.debug(f"Disconnecting by key: {key}") + client_instance.disconnect() run([ - u"ssh", u"-S", self._ssh_control_socket, u"-O", u"exit", u"0.0.0.0" + u"ssh", u"-S", client_instance.csit_control_socket, u"-O", + u"exit", u"0.0.0.0" ], check=False) - shutil.rmtree(self._temp_dir) + # Temp dir has autoclean, but deleting explicitly + # as an error can happen. + try: + client_instance.csit_temp_dir.cleanup() + except FileNotFoundError: + # There is a race condition with ssh removing its ssh.sock file. + # Single retry should be enough to ensure the complete removal. + shutil.rmtree(client_instance.csit_temp_dir.name) + # Finally, put disconnected clients to reuse list. + cls.reusable_vpp_client_list.append(client_instance) + # Invalidate cache last. Repeated errors are better than silent leaks. + del cls.conn_cache[key] + + @classmethod + def disconnect_by_node_and_socket( + cls, node, remote_socket=Constants.SOCKSVR_PATH + ): + """Disconnect a connected client instance, noop it not connected. + + Also remove the local sockets by deleting the temporary directory. + Put disconnected client instances to the reuse list. + The added attributes are not cleaned up, + as their values will get overwritten on next connect. + + Call this method just before killing/restarting remote VPP instance. + """ + key = cls.key_for_node_and_socket(node, remote_socket) + return cls.disconnect_by_key(key) + + @classmethod + def disconnect_all_sockets_by_node(cls, node): + """Disconnect all socket connected client instance. + + Noop if not connected. + + Also remove the local sockets by deleting the temporary directory. + Put disconnected client instances to the reuse list. + The added attributes are not cleaned up, + as their values will get overwritten on next connect. + + Call this method just before killing/restarting remote VPP instance. + """ + sockets = Topology.get_node_sockets(node, socket_type=SocketType.PAPI) + if sockets: + for socket in sockets.values(): + # TODO: Remove sockets from topology. + PapiSocketExecutor.disconnect_by_node_and_socket(node, socket) + # Always attempt to disconnect the default socket. + return cls.disconnect_by_node_and_socket(node) + + @staticmethod + def disconnect_all_papi_connections(): + """Disconnect all connected client instances, tear down the SSH tunnels. + + Also remove the local sockets by deleting the temporary directory. + Put disconnected client instances to the reuse list. + The added attributes are not cleaned up, + as their values will get overwritten on next connect. + + This should be a class method, + but we prefer to call static methods from Robot. + + Call this method just before killing/restarting all VPP instances. + """ + cls = PapiSocketExecutor + # Iterate over copy of entries so deletions do not mess with iterator. + keys_copy = list(cls.conn_cache.keys()) + for key in keys_copy: + cls.disconnect_by_key(key) def add(self, csit_papi_command, history=True, **kwargs): """Add next command to internal command list; return self. @@ -517,7 +766,7 @@ class PapiSocketExecutor: :rtype: list of dict :raises RuntimeError: If the replies are not all correct. """ - vpp_instance = self.vpp_instance + vpp_instance = self.get_connected_client() local_list = self._api_command_list # Clear first as execution may fail. self._api_command_list = list() @@ -531,10 +780,10 @@ class PapiSocketExecutor: except (IOError, struct.error) as err: # Occasionally an error happens, try reconnect. logger.warn(f"Reconnect after error: {err!r}") - self.vpp_instance.disconnect() + vpp_instance.disconnect() # Testing shows immediate reconnect fails. time.sleep(1) - self.vpp_instance.connect_sync(u"csit_socket") + vpp_instance.connect_sync(u"csit_socket") logger.trace(u"Reconnected.") reply = papi_fn(**command[u"api_args"]) except (AttributeError, IOError, struct.error) as err: @@ -558,6 +807,33 @@ class PapiSocketExecutor: return replies +class Disconnector: + """Class for holding a single keyword.""" + + @staticmethod + def disconnect_all_papi_connections(): + """Disconnect all connected client instances, tear down the SSH tunnels. + + Also remove the local sockets by deleting the temporary directory. + Put disconnected client instances to the reuse list. + The added attributes are not cleaned up, + as their values will get overwritten on next connect. + + Call this method just before killing/restarting all VPP instances. + + This could be a class method of PapiSocketExecutor. + But Robot calls methods on instances, and it would be weird + to give node argument for constructor in import. + Also, as we have a class of the same name as the module, + the keywords defined on module level are not accessible. + """ + cls = PapiSocketExecutor + # Iterate over copy of entries so deletions do not mess with iterator. + keys_copy = list(cls.conn_cache.keys()) + for key in keys_copy: + cls.disconnect_by_key(key) + + class PapiExecutor: """Contains methods for executing VPP Python API commands on DUTs. |