-# Copyright (c) 2018 Cisco and/or its affiliates.
+# Copyright (c) 2019 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:
"""Library for SSH connection management."""
+
+import socket
import StringIO
from time import time, sleep
-import socket
-import paramiko
-from paramiko import RSAKey
-from paramiko.ssh_exception import SSHException
-from scp import SCPClient
+from paramiko import RSAKey, SSHClient, AutoAddPolicy
+from paramiko.ssh_exception import SSHException, NoValidConnectionsError
from robot.api import logger
+from scp import SCPClient, SCPException
+
+from resources.libraries.python.OptionString import OptionString
__all__ = ["exec_cmd", "exec_cmd_no_error"]
# TODO: load priv key
+def raise_from(raising, excepted):
+ """Function to be replaced by "raise from" in Python 3.
+
+ Neither "six" nor "future" offer good enough implementation right now.
+ chezsoi.org/lucas/blog/displaying-chained-exceptions-stacktraces-in-python-2
+
+ Current implementation just logs excepted error, and raises the new one.
+
+ :param raising: The exception to raise.
+ :param excepted: The exception we excepted and want to log.
+ :type raising: BaseException
+ :type excepted: BaseException
+ :raises: raising
+ """
+ logger.error("Excepted: {exc!r}\nRaising: {rai!r}".format(
+ exc=excepted, rai=raising))
+ raise raising
+
+
class SSHTimeout(Exception):
"""This exception is raised when a timeout occurs."""
pass
pkey = RSAKey.from_private_key(
StringIO.StringIO(node['priv_key']))
- self._ssh = paramiko.SSHClient()
- self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+ self._ssh = SSHClient()
+ self._ssh.set_missing_host_key_policy(AutoAddPolicy())
self._ssh.connect(node['host'], username=node['username'],
password=node.get('password'), pkey=pkey,
peer=self._ssh.get_transport().getpeername(),
total=(time() - start),
ssh=self._ssh))
- except SSHException:
- raise IOError('Cannot connect to {host}'.
- format(host=node['host']))
-
- def disconnect(self, node):
+ except SSHException as exc:
+ raise_from(IOError('Cannot connect to {host}'.format(
+ host=node['host'])), exc)
+ except NoValidConnectionsError as err:
+ raise_from(IOError(
+ 'Unable to connect to port {port} on {host}'.format(
+ port=node['port'], host=node['host'])), err)
+
+ def disconnect(self, node=None):
"""Close SSH connection to the node.
- :param node: The node to disconnect from.
- :type node: dict
+ :param node: The node to disconnect from. None means last connected.
+ :type node: dict or None
"""
+ if node is None:
+ node = self._node
+ if node is None:
+ return
node_hash = self._node_hash(node)
if node_hash in SSH.__existing_connections:
logger.debug('Disconnecting peer: {host}, {port}'.
logger.debug('Reconnecting peer done: {host}, {port}'.
format(host=node['host'], port=node['port']))
- def exec_command(self, cmd, timeout=10):
+ def exec_command(self, cmd, timeout=10, log_stdout_err=True):
"""Execute SSH command on a new channel on the connected Node.
:param cmd: Command to run on the Node.
:param timeout: Maximal time in seconds to wait until the command is
- done. If set to None then wait forever.
- :type cmd: str
+ done. If set to None then wait forever.
+ :param log_stdout_err: If True, stdout and stderr are logged. stdout
+ and stderr are logged also if the return code is not zero
+ independently of the value of log_stdout_err.
+ :type cmd: str or OptionString
:type timeout: int
- :return return_code, stdout, stderr
+ :type log_stdout_err: bool
+ :returns: return_code, stdout, stderr
:rtype: tuple(int, str, str)
- :raise SSHTimeout: If command is not finished in timeout time.
+ :raises SSHTimeout: If command is not finished in timeout time.
"""
+ if isinstance(cmd, (list, tuple)):
+ cmd = OptionString(cmd)
+ cmd = str(cmd)
stdout = StringIO.StringIO()
stderr = StringIO.StringIO()
try:
chan = self._ssh.get_transport().open_session(timeout=5)
peer = self._ssh.get_transport().getpeername()
- except AttributeError:
- self._reconnect()
- chan = self._ssh.get_transport().open_session(timeout=5)
- peer = self._ssh.get_transport().getpeername()
- except SSHException:
+ except (AttributeError, SSHException):
self._reconnect()
chan = self._ssh.get_transport().open_session(timeout=5)
peer = self._ssh.get_transport().getpeername()
format(peer=peer, total=end-start))
logger.trace('return RC {rc}'.format(rc=return_code))
- logger.trace('return STDOUT {stdout}'.format(stdout=stdout.getvalue()))
- logger.trace('return STDERR {stderr}'.format(stderr=stderr.getvalue()))
+ if log_stdout_err or int(return_code):
+ logger.trace('return STDOUT {stdout}'.
+ format(stdout=stdout.getvalue()))
+ logger.trace('return STDERR {stderr}'.
+ format(stderr=stderr.getvalue()))
return return_code, stdout.getvalue(), stderr.getvalue()
- def exec_command_sudo(self, cmd, cmd_input=None, timeout=30):
+ def exec_command_sudo(self, cmd, cmd_input=None, timeout=30,
+ log_stdout_err=True):
"""Execute SSH command with sudo on a new channel on the connected Node.
:param cmd: Command to be executed.
:param cmd_input: Input redirected to the command.
:param timeout: Timeout.
+ :param log_stdout_err: If True, stdout and stderr are logged.
+ :type cmd: str
+ :type cmd_input: str
+ :type timeout: int
+ :type log_stdout_err: bool
:returns: return_code, stdout, stderr
+ :rtype: tuple(int, str, str)
:Example:
>>> # Execute command with input (sudo -S cmd <<< "input")
>>> ssh.exec_command_sudo("vpp_api_test", "dump_interface_table")
"""
+ if isinstance(cmd, (list, tuple)):
+ cmd = OptionString(cmd)
if cmd_input is None:
command = 'sudo -S {c}'.format(c=cmd)
else:
command = 'sudo -S {c} <<< "{i}"'.format(c=cmd, i=cmd_input)
- return self.exec_command(command, timeout)
+ return self.exec_command(command, timeout,
+ log_stdout_err=log_stdout_err)
def exec_command_lxc(self, lxc_cmd, lxc_name, lxc_params='', sudo=True,
timeout=30):
if chan.exit_status_ready():
logger.error('Channel exit status ready')
break
- except socket.timeout:
- logger.error('Socket timeout: {0}'.format(buf))
- raise Exception('Socket timeout: {0}'.format(buf))
+ except socket.timeout as exc:
+ raise_from(Exception('Socket timeout: {0}'.format(buf)), exc)
return chan
def interactive_terminal_exec_command(self, chan, cmd, prompt):
if chan.exit_status_ready():
logger.error('Channel exit status ready')
break
- except socket.timeout:
- logger.error('Socket timeout during execution of command: '
- '{0}\nBuffer content:\n{1}'.format(cmd, buf))
- raise Exception('Socket timeout during execution of command: '
- '{0}\nBuffer content:\n{1}'.format(cmd, buf))
+ except socket.timeout as exc:
+ raise_from(Exception(
+ 'Socket timeout during execution of command: '
+ '{0}\nBuffer content:\n{1}'.format(cmd, buf)), exc)
tmp = buf.replace(cmd.replace('\n', ''), '')
for item in prompt:
tmp.replace(item, '')
def interactive_terminal_close(chan):
"""Close interactive terminal SSH channel.
- :param: chan: SSH channel to be closed.
+ :param chan: SSH channel to be closed.
"""
chan.close()
logger.trace('SCP took {0} seconds'.format(end-start))
-def exec_cmd(node, cmd, timeout=600, sudo=False):
+def exec_cmd(node, cmd, timeout=600, sudo=False, disconnect=False):
"""Convenience function to ssh/exec/return rc, out & err.
Returns (rc, stdout, stderr).
+
+ :param node: The node to execute command on.
+ :param cmd: Command to execute.
+ :param timeout: Timeout value in seconds. Default: 600.
+ :param sudo: Sudo privilege execution flag. Default: False.
+ :param disconnect: Close the opened SSH connection if True.
+ :type node: dict
+ :type cmd: str or OptionString
+ :type timeout: int
+ :type sudo: bool
+ :type disconnect: bool
+ :returns: RC, Stdout, Stderr.
+ :rtype: tuple(int, str, str)
"""
if node is None:
raise TypeError('Node parameter is None')
raise ValueError('Empty command parameter')
ssh = SSH()
+
+ if node.get('host_port') is not None:
+ ssh_node = dict()
+ ssh_node['host'] = '127.0.0.1'
+ ssh_node['port'] = node['port']
+ ssh_node['username'] = node['username']
+ ssh_node['password'] = node['password']
+ import pexpect
+ options = '-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'
+ tnl = '-L {port}:127.0.0.1:{port}'.format(port=node['port'])
+ ssh_cmd = 'ssh {tnl} {op} {user}@{host} -p {host_port}'.\
+ format(tnl=tnl, op=options, user=node['host_username'],
+ host=node['host'], host_port=node['host_port'])
+ logger.trace('Initializing local port forwarding:\n{ssh_cmd}'.
+ format(ssh_cmd=ssh_cmd))
+ child = pexpect.spawn(ssh_cmd)
+ child.expect('.* password: ')
+ logger.trace(child.after)
+ child.sendline(node['host_password'])
+ child.expect('Welcome .*')
+ logger.trace(child.after)
+ logger.trace('Local port forwarding finished.')
+ else:
+ ssh_node = node
+
try:
- ssh.connect(node)
+ ssh.connect(ssh_node)
except SSHException as err:
- logger.error("Failed to connect to node" + str(err))
+ logger.error("Failed to connect to node" + repr(err))
return None, None, None
try:
(ret_code, stdout, stderr) = ssh.exec_command_sudo(cmd,
timeout=timeout)
except SSHException as err:
- logger.error(err)
+ logger.error(repr(err))
return None, None, None
+ finally:
+ if disconnect:
+ ssh.disconnect()
return ret_code, stdout, stderr
-def exec_cmd_no_error(node, cmd, timeout=600, sudo=False, message=None):
+def exec_cmd_no_error(
+ node, cmd, timeout=600, sudo=False, message=None, disconnect=False,
+ retries=0, include_reason=False):
"""Convenience function to ssh/exec/return out & err.
Verifies that return code is zero.
+ Supports retries, timeout is related to each try separately then. There is
+ sleep(1) before each retry.
+ Disconnect (if enabled) is applied after each try.
:param node: DUT node.
:param cmd: Command to be executed.
:param timeout: Timeout value in seconds. Default: 600.
:param sudo: Sudo privilege execution flag. Default: False.
:param message: Error message in case of failure. Default: None.
+ :param disconnect: Close the opened SSH connection if True.
+ :param retries: How many times to retry on failure.
+ :param include_reason: Whether default info should be appended to message.
:type node: dict
- :type cmd: str
+ :type cmd: str or OptionString
:type timeout: int
:type sudo: bool
:type message: str
+ :type disconnect: bool
+ :type retries: int
+ :type include_reason: bool
:returns: Stdout, Stderr.
:rtype: tuple(str, str)
- :raise RuntimeError: If bash return code is not 0.
+ :raises RuntimeError: If bash return code is not 0.
"""
- ret_code, stdout, stderr = exec_cmd(node, cmd, timeout=timeout, sudo=sudo)
- msg = ('Command execution failed: "{cmd}"\n{stderr}'.
- format(cmd=cmd, stderr=stderr) if message is None else message)
- if ret_code != 0:
+ for _ in range(retries + 1):
+ ret_code, stdout, stderr = exec_cmd(
+ node, cmd, timeout=timeout, sudo=sudo, disconnect=disconnect)
+ if ret_code == 0:
+ break
+ sleep(1)
+ else:
+ msg = 'Command execution failed: "{cmd}"\nRC: {rc}\n{stderr}'.format(
+ cmd=cmd, rc=ret_code, stderr=stderr)
+ logger.info(msg)
+ if message:
+ if include_reason:
+ msg = message + '\n' + msg
+ else:
+ msg = message
raise RuntimeError(msg)
return stdout, stderr
+
+
+def scp_node(
+ node, local_path, remote_path, get=False, timeout=30, disconnect=False):
+ """Copy files from local_path to remote_path or vice versa.
+
+ :param node: SUT node.
+ :param local_path: Path to local file that should be uploaded; or
+ path where to save remote file.
+ :param remote_path: Remote path where to place uploaded file; or
+ path to remote file which should be downloaded.
+ :param get: scp operation to perform. Default is put.
+ :param timeout: Timeout value in seconds.
+ :param disconnect: Close the opened SSH connection if True.
+ :type node: dict
+ :type local_path: str
+ :type remote_path: str
+ :type get: bool
+ :type timeout: int
+ :type disconnect: bool
+ :raises RuntimeError: If SSH connection failed or SCP transfer failed.
+ """
+ ssh = SSH()
+
+ try:
+ ssh.connect(node)
+ except SSHException as exc:
+ raise_from(RuntimeError(
+ 'Failed to connect to {host}!'.format(host=node['host'])), exc)
+ try:
+ ssh.scp(local_path, remote_path, get, timeout)
+ except SCPException as exc:
+ raise_from(RuntimeError(
+ 'SCP execution failed on {host}!'.format(host=node['host'])), exc)
+ finally:
+ if disconnect:
+ ssh.disconnect()
Code Review / csit.git / blobdiff