1 # Copyright (c) 2016 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 from paramiko import RSAKey
16 from scp import SCPClient
18 from robot.api import logger
19 from interruptingcow import timeout
20 from robot.utils.asserts import assert_equal, assert_not_equal
21 from socket import timeout as socket_timeout
23 __all__ = ["exec_cmd", "exec_cmd_no_error"]
30 __MAX_RECV_BUF = 10*1024*1024
31 __existing_connections = {}
36 def _node_hash(self, node):
37 return hash(frozenset([node['host'], node['port']]))
39 def connect(self, node):
40 """Connect to node prior to running exec_command or scp.
42 If there already is a connection to the node, this method reuses it.
44 node_hash = self._node_hash(node)
45 if node_hash in SSH.__existing_connections:
46 self._ssh = SSH.__existing_connections[node_hash]
47 logger.debug('reusing ssh: {0}'.format(self._ssh))
51 if 'priv_key' in node:
52 pkey = RSAKey.from_private_key(
53 StringIO.StringIO(node['priv_key']))
55 self._ssh = paramiko.SSHClient()
56 self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
58 self._ssh.connect(node['host'], username=node['username'],
59 password=node.get('password'), pkey=pkey)
61 SSH.__existing_connections[node_hash] = self._ssh
63 logger.trace('connect took {} seconds'.format(time() - start))
64 logger.debug('new ssh: {0}'.format(self._ssh))
66 logger.debug('Connect peer: {0}'.
67 format(self._ssh.get_transport().getpeername()))
68 logger.debug('Connections: {0}'.format(str(SSH.__existing_connections)))
70 def exec_command(self, cmd, timeout=10):
71 """Execute SSH command on a new channel on the connected Node.
73 Returns (return_code, stdout, stderr).
75 logger.trace('exec_command on {0}: {1}'
76 .format(self._ssh.get_transport().getpeername(), cmd))
78 chan = self._ssh.get_transport().open_session()
79 if timeout is not None:
80 chan.settimeout(int(timeout))
81 chan.exec_command(cmd)
83 logger.trace('exec_command on {0} took {1} seconds'.format(
84 self._ssh.get_transport().getpeername(), end-start))
89 buf = chan.recv(self.__MAX_RECV_BUF)
93 except socket_timeout:
94 logger.trace('Channels stdout timeout occurred')
100 buf = chan.recv_stderr(self.__MAX_RECV_BUF)
104 except socket_timeout:
105 logger.trace('Channels stderr timeout occurred')
108 return_code = chan.recv_exit_status()
109 logger.trace('chan_recv/_stderr took {} seconds'.format(time()-end))
111 logger.trace('return RC {}'.format(return_code))
112 logger.trace('return STDOUT {}'.format(stdout))
113 logger.trace('return STDERR {}'.format(stderr))
114 return return_code, stdout, stderr
116 def exec_command_sudo(self, cmd, cmd_input=None, timeout=10):
117 """Execute SSH command with sudo on a new channel on the connected Node.
119 :param cmd: Command to be executed.
120 :param cmd_input: Input redirected to the command.
121 :param timeout: Timeout.
122 :return: return_code, stdout, stderr
126 >>> from ssh import SSH
128 >>> ssh.connect(node)
129 >>> #Execute command without input (sudo -S cmd)
130 >>> ssh.exec_command_sudo("ifconfig eth0 down")
131 >>> #Execute command with input (sudo -S cmd <<< "input")
132 >>> ssh.exec_command_sudo("vpp_api_test", "dump_interface_table")
134 if cmd_input is None:
135 command = 'sudo -S {c}'.format(c=cmd)
137 command = 'sudo -S {c} <<< "{i}"'.format(c=cmd, i=cmd_input)
138 return self.exec_command(command, timeout)
140 def interactive_terminal_open(self, time_out=10):
141 """Open interactive terminal on a new channel on the connected Node.
143 :param time_out: Timeout in seconds.
144 :return: SSH channel with opened terminal.
146 .. warning:: Interruptingcow is used here, and it uses
147 signal(SIGALRM) to let the operating system interrupt program
148 execution. This has the following limitations: Python signal
149 handlers only apply to the main thread, so you cannot use this
150 from other threads. You must not use this in a program that
151 uses SIGALRM itself (this includes certain profilers)
153 chan = self._ssh.get_transport().open_session()
156 chan.settimeout(int(time_out))
160 with timeout(time_out, exception=RuntimeError):
161 while not buf.endswith(':~$ '):
162 if chan.recv_ready():
163 buf = chan.recv(4096)
165 raise Exception('Open interactive terminal timeout.')
168 def interactive_terminal_exec_command(self, chan, cmd, prompt,
170 """Execute command on interactive terminal.
172 interactive_terminal_open() method has to be called first!
174 :param chan: SSH channel with opened terminal.
175 :param cmd: Command to be executed.
176 :param prompt: Command prompt, sequence of characters used to
177 indicate readiness to accept commands.
178 :param time_out: Timeout in seconds.
179 :return: Command output.
181 .. warning:: Interruptingcow is used here, and it uses
182 signal(SIGALRM) to let the operating system interrupt program
183 execution. This has the following limitations: Python signal
184 handlers only apply to the main thread, so you cannot use this
185 from other threads. You must not use this in a program that
186 uses SIGALRM itself (this includes certain profilers)
188 chan.sendall('{c}\n'.format(c=cmd))
191 with timeout(time_out, exception=RuntimeError):
192 while not buf.endswith(prompt):
193 if chan.recv_ready():
194 buf += chan.recv(4096)
196 raise Exception("Exec '{c}' timeout.".format(c=cmd))
197 tmp = buf.replace(cmd.replace('\n', ''), '')
198 return tmp.replace(prompt, '')
200 def interactive_terminal_close(self, chan):
201 """Close interactive terminal SSH channel.
203 :param: chan: SSH channel to be closed.
207 def scp(self, local_path, remote_path):
208 """Copy files from local_path to remote_path.
210 connect() method has to be called first!
212 logger.trace('SCP {0} to {1}:{2}'.format(
213 local_path, self._ssh.get_transport().getpeername(), remote_path))
214 # SCPCLient takes a paramiko transport as its only argument
215 scp = SCPClient(self._ssh.get_transport())
217 scp.put(local_path, remote_path)
220 logger.trace('SCP took {0} seconds'.format(end-start))
223 def exec_cmd(node, cmd, timeout=None, sudo=False):
224 """Convenience function to ssh/exec/return rc, out & err.
226 Returns (rc, stdout, stderr).
229 raise TypeError('Node parameter is None')
231 raise TypeError('Command parameter is None')
233 raise ValueError('Empty command parameter')
239 logger.error("Failed to connect to node" + e)
244 (ret_code, stdout, stderr) = ssh.exec_command(cmd, timeout=timeout)
246 (ret_code, stdout, stderr) = ssh.exec_command_sudo(cmd,
252 return (ret_code, stdout, stderr)
254 def exec_cmd_no_error(node, cmd, timeout=None, sudo=False):
255 """Convenience function to ssh/exec/return out & err.
256 Verifies that return code is zero.
258 Returns (stdout, stderr).
260 (rc, stdout, stderr) = exec_cmd(node, cmd, timeout=timeout, sudo=sudo)
261 assert_equal(rc, 0, 'Command execution failed: "{}"\n{}'.
263 return (stdout, stderr)