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Diffstat (limited to 'test/resources/libraries/python/ssh.py')
-rw-r--r-- | test/resources/libraries/python/ssh.py | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/test/resources/libraries/python/ssh.py b/test/resources/libraries/python/ssh.py new file mode 100644 index 00000000..0887a765 --- /dev/null +++ b/test/resources/libraries/python/ssh.py @@ -0,0 +1,127 @@ +# Copyright (c) 2015 Cisco and/or its affiliates. +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at: +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +import paramiko +from scp import SCPClient +from time import time +from robot.api import logger + +__all__ = ["exec_cmd"] + +# TODO: Attempt to recycle SSH connections +# TODO: load priv key + +class SSH(object): + + __MAX_RECV_BUF = 10*1024*1024 + __existing_connections = {} + + def __init__(self): + self._ssh = paramiko.SSHClient() + self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) + self._hostname = None + + def _node_hash(self, node): + return hash(frozenset([node['host'], node['port']])) + + def connect(self, node): + """Connect to node prior to running exec_command or scp. + + If there already is a connection to the node, this method reuses it. + """ + self._hostname = node['host'] + node_hash = self._node_hash(node) + if node_hash in self.__existing_connections: + self._ssh = self.__existing_connections[node_hash] + else: + start = time() + self._ssh.connect(node['host'], username=node['username'], + password=node['password']) + self.__existing_connections[node_hash] = self._ssh + logger.trace('connect took {} seconds'.format(time() - start)) + + def exec_command(self, cmd, timeout=10): + """Execute SSH command on a new channel on the connected Node. + + Returns (return_code, stdout, stderr). + """ + start = time() + chan = self._ssh.get_transport().open_session() + if timeout is not None: + chan.settimeout(int(timeout)) + chan.exec_command(cmd) + end = time() + logger.trace('exec_command "{0}" on {1} took {2} seconds'.format(cmd, + self._hostname, end-start)) + + + stdout = "" + while True: + buf = chan.recv(self.__MAX_RECV_BUF) + stdout += buf + if not buf: + break + + stderr = "" + while True: + buf = chan.recv_stderr(self.__MAX_RECV_BUF) + stderr += buf + if not buf: + break + + return_code = chan.recv_exit_status() + logger.trace('chan_recv/_stderr took {} seconds'.format(time()-end)) + + return (return_code, stdout, stderr) + + def scp(self, local_path, remote_path): + """Copy files from local_path to remote_path. + + connect() method has to be called first! + """ + logger.trace('SCP {0} to {1}:{2}'.format( + local_path, self._hostname, remote_path)) + # SCPCLient takes a paramiko transport as its only argument + scp = SCPClient(self._ssh.get_transport()) + start = time() + scp.put(local_path, remote_path) + scp.close() + end = time() + logger.trace('SCP took {0} seconds'.format(end-start)) + +def exec_cmd(node, cmd, timeout=None): + """Convenience function to ssh/exec/return rc & out. + + Returns (rc, stdout). + """ + if node is None: + raise TypeError('Node parameter is None') + if cmd is None: + raise TypeError('Command parameter is None') + if len(cmd) == 0: + raise ValueError('Empty command parameter') + + ssh = SSH() + try: + ssh.connect(node) + except Exception, e: + logger.error("Failed to connect to node" + e) + return None + + try: + (ret_code, stdout, stderr) = ssh.exec_command(cmd, timeout=timeout) + except Exception, e: + logger.error(e) + return None + + return (ret_code, stdout, stderr) + |