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,
62 SSH.__existing_connections[node_hash] = self._ssh
64 logger.trace('connect took {} seconds'.format(time() - start))
65 logger.debug('new ssh: {0}'.format(self._ssh))
67 logger.debug('Connect peer: {0}'.
68 format(self._ssh.get_transport().getpeername()))
69 logger.debug('Connections: {0}'.format(str(SSH.__existing_connections)))
71 def exec_command(self, cmd, timeout=10):
72 """Execute SSH command on a new channel on the connected Node.
74 Returns (return_code, stdout, stderr).
76 logger.trace('exec_command on {0}: {1}'
77 .format(self._ssh.get_transport().getpeername(), cmd))
79 chan = self._ssh.get_transport().open_session()
80 if timeout is not None:
81 chan.settimeout(int(timeout))
82 chan.exec_command(cmd)
84 logger.trace('exec_command on {0} took {1} seconds'.format(
85 self._ssh.get_transport().getpeername(), end-start))
90 buf = chan.recv(self.__MAX_RECV_BUF)
94 except socket_timeout:
95 logger.trace('Channels stdout timeout occurred')
101 buf = chan.recv_stderr(self.__MAX_RECV_BUF)
105 except socket_timeout:
106 logger.trace('Channels stderr timeout occurred')
109 return_code = chan.recv_exit_status()
110 logger.trace('chan_recv/_stderr took {} seconds'.format(time()-end))
112 logger.trace('return RC {}'.format(return_code))
113 logger.trace('return STDOUT {}'.format(stdout))
114 logger.trace('return STDERR {}'.format(stderr))
115 return return_code, stdout, stderr
117 def exec_command_sudo(self, cmd, cmd_input=None, timeout=10):
118 """Execute SSH command with sudo on a new channel on the connected Node.
120 :param cmd: Command to be executed.
121 :param cmd_input: Input redirected to the command.
122 :param timeout: Timeout.
123 :return: return_code, stdout, stderr
127 >>> from ssh import SSH
129 >>> ssh.connect(node)
130 >>> #Execute command without input (sudo -S cmd)
131 >>> ssh.exec_command_sudo("ifconfig eth0 down")
132 >>> #Execute command with input (sudo -S cmd <<< "input")
133 >>> ssh.exec_command_sudo("vpp_api_test", "dump_interface_table")
135 if cmd_input is None:
136 command = 'sudo -S {c}'.format(c=cmd)
138 command = 'sudo -S {c} <<< "{i}"'.format(c=cmd, i=cmd_input)
139 return self.exec_command(command, timeout)
141 def interactive_terminal_open(self, time_out=10):
142 """Open interactive terminal on a new channel on the connected Node.
144 :param time_out: Timeout in seconds.
145 :return: SSH channel with opened terminal.
147 .. warning:: Interruptingcow is used here, and it uses
148 signal(SIGALRM) to let the operating system interrupt program
149 execution. This has the following limitations: Python signal
150 handlers only apply to the main thread, so you cannot use this
151 from other threads. You must not use this in a program that
152 uses SIGALRM itself (this includes certain profilers)
154 chan = self._ssh.get_transport().open_session()
157 chan.settimeout(int(time_out))
161 with timeout(time_out, exception=RuntimeError):
162 while not buf.endswith(':~$ '):
163 if chan.recv_ready():
164 buf = chan.recv(4096)
166 raise Exception('Open interactive terminal timeout.')
169 def interactive_terminal_exec_command(self, chan, cmd, prompt,
171 """Execute command on interactive terminal.
173 interactive_terminal_open() method has to be called first!
175 :param chan: SSH channel with opened terminal.
176 :param cmd: Command to be executed.
177 :param prompt: Command prompt, sequence of characters used to
178 indicate readiness to accept commands.
179 :param time_out: Timeout in seconds.
180 :return: Command output.
182 .. warning:: Interruptingcow is used here, and it uses
183 signal(SIGALRM) to let the operating system interrupt program
184 execution. This has the following limitations: Python signal
185 handlers only apply to the main thread, so you cannot use this
186 from other threads. You must not use this in a program that
187 uses SIGALRM itself (this includes certain profilers)
189 chan.sendall('{c}\n'.format(c=cmd))
192 with timeout(time_out, exception=RuntimeError):
193 while not buf.endswith(prompt):
194 if chan.recv_ready():
195 buf += chan.recv(4096)
197 raise Exception("Exec '{c}' timeout.".format(c=cmd))
198 tmp = buf.replace(cmd.replace('\n', ''), '')
199 return tmp.replace(prompt, '')
201 def interactive_terminal_close(self, chan):
202 """Close interactive terminal SSH channel.
204 :param: chan: SSH channel to be closed.
208 def scp(self, local_path, remote_path):
209 """Copy files from local_path to remote_path.
211 connect() method has to be called first!
213 logger.trace('SCP {0} to {1}:{2}'.format(
214 local_path, self._ssh.get_transport().getpeername(), remote_path))
215 # SCPCLient takes a paramiko transport as its only argument
216 scp = SCPClient(self._ssh.get_transport())
218 scp.put(local_path, remote_path)
221 logger.trace('SCP took {0} seconds'.format(end-start))
224 def exec_cmd(node, cmd, timeout=None, sudo=False):
225 """Convenience function to ssh/exec/return rc, out & err.
227 Returns (rc, stdout, stderr).
230 raise TypeError('Node parameter is None')
232 raise TypeError('Command parameter is None')
234 raise ValueError('Empty command parameter')
240 logger.error("Failed to connect to node" + e)
245 (ret_code, stdout, stderr) = ssh.exec_command(cmd, timeout=timeout)
247 (ret_code, stdout, stderr) = ssh.exec_command_sudo(cmd,
253 return (ret_code, stdout, stderr)
255 def exec_cmd_no_error(node, cmd, timeout=None, sudo=False):
256 """Convenience function to ssh/exec/return out & err.
257 Verifies that return code is zero.
259 Returns (stdout, stderr).
261 (rc, stdout, stderr) = exec_cmd(node, cmd, timeout=timeout, sudo=sudo)
262 assert_equal(rc, 0, 'Command execution failed: "{}"\n{}'.
264 return (stdout, stderr)