X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=blobdiff_plain;f=resources%2Flibraries%2Fpython%2Fssh.py;h=e89daf291528e45825aafcf65846e8a8b8f49614;hp=469d77ffc2cef5cba6936d670fa4b9c687007eb2;hb=72ae46cda69c2f12efdbe731e37dce200a48f424;hpb=d1d8f2b387d3fd625ac98bc5bc37ff344b98ead8 diff --git a/resources/libraries/python/ssh.py b/resources/libraries/python/ssh.py index 469d77ffc2..e89daf2915 100644 --- a/resources/libraries/python/ssh.py +++ b/resources/libraries/python/ssh.py @@ -1,4 +1,4 @@ -# Copyright (c) 2016 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: @@ -13,16 +13,17 @@ """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 robot.utils.asserts import assert_equal +from scp import SCPClient, SCPException + __all__ = ["exec_cmd", "exec_cmd_no_error"] @@ -50,7 +51,7 @@ class SSH(object): :param node: Node in topology. :type node: dict - :return: IP address and port for the specified node. + :returns: IP address and port for the specified node. :rtype: int """ @@ -60,22 +61,35 @@ class SSH(object): """Connect to node prior to running exec_command or scp. If there already is a connection to the node, this method reuses it. + + :param node: Node in topology. + :param attempts: Number of reconnect attempts. + :type node: dict + :type attempts: int + :raises IOError: If cannot connect to host. """ - try: - self._node = node - node_hash = self._node_hash(node) - if node_hash in SSH.__existing_connections: - self._ssh = SSH.__existing_connections[node_hash] - logger.debug('reusing ssh: {0}'.format(self._ssh)) + self._node = node + node_hash = self._node_hash(node) + if node_hash in SSH.__existing_connections: + self._ssh = SSH.__existing_connections[node_hash] + if self._ssh.get_transport().is_active(): + logger.debug('Reusing SSH: {ssh}'.format(ssh=self._ssh)) else: + if attempts > 0: + self._reconnect(attempts-1) + else: + raise IOError('Cannot connect to {host}'. + format(host=node['host'])) + else: + try: start = time() pkey = None if 'priv_key' in node: 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, @@ -84,54 +98,65 @@ class SSH(object): self._ssh.get_transport().set_keepalive(10) SSH.__existing_connections[node_hash] = self._ssh - - logger.trace('connect took {} seconds'.format(time() - start)) - logger.debug('new ssh: {0}'.format(self._ssh)) - - logger.debug('Connect peer: {0}'. - format(self._ssh.get_transport().getpeername())) - logger.debug('Connections: {0}'. - format(str(SSH.__existing_connections))) - except: - if attempts > 0: - self._reconnect(attempts-1) - else: - raise - - def disconnect(self, node): + logger.debug('New SSH to {peer} took {total} seconds: {ssh}'. + format( + peer=self._ssh.get_transport().getpeername(), + total=(time() - start), + ssh=self._ssh)) + except SSHException: + raise IOError('Cannot connect to {host}'. + format(host=node['host'])) + except NoValidConnectionsError as err: + logger.error(repr(err)) + raise IOError('Unable to connect to port {port} on {host}'. + format(port=node['port'], host=node['host'])) + + 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: {}, {}'. - format(node['host'], node['port'])) + logger.debug('Disconnecting peer: {host}, {port}'. + format(host=node['host'], port=node['port'])) ssh = SSH.__existing_connections.pop(node_hash) ssh.close() def _reconnect(self, attempts=0): - """Close the SSH connection and open it again.""" + """Close the SSH connection and open it again. + :param attempts: Number of reconnect attempts. + :type attempts: int + """ node = self._node self.disconnect(node) self.connect(node, attempts) - logger.debug('Reconnecting peer done: {}'. - format(self._ssh.get_transport().getpeername())) + 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. """ + cmd = str(cmd) stdout = StringIO.StringIO() stderr = StringIO.StringIO() try: @@ -182,17 +207,27 @@ class SSH(object): 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. - :return: return_code, stdout, stderr + :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: @@ -208,7 +243,8 @@ class SSH(object): 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): @@ -224,7 +260,7 @@ class SSH(object): :type lxc_params: str :type sudo: bool :type timeout: int - :return: return_code, stdout, stderr + :returns: return_code, stdout, stderr """ command = "lxc-attach {p} --name {n} -- /bin/sh -c '{c}'"\ .format(p=lxc_params, n=lxc_name, c=lxc_cmd) @@ -233,11 +269,11 @@ class SSH(object): command = 'sudo -S {c}'.format(c=command) return self.exec_command(command, timeout) - def interactive_terminal_open(self, time_out=30): + def interactive_terminal_open(self, time_out=45): """Open interactive terminal on a new channel on the connected Node. :param time_out: Timeout in seconds. - :return: SSH channel with opened terminal. + :returns: SSH channel with opened terminal. .. warning:: Interruptingcow is used here, and it uses signal(SIGALRM) to let the operating system interrupt program @@ -253,7 +289,7 @@ class SSH(object): chan.set_combine_stderr(True) buf = '' - while not buf.endswith((":~$ ", "~]$ ", "~]# ")): + while not buf.endswith((":~# ", ":~$ ", "~]$ ", "~]# ")): try: chunk = chan.recv(self.__MAX_RECV_BUF) if not chunk: @@ -276,7 +312,7 @@ class SSH(object): :param cmd: Command to be executed. :param prompt: Command prompt, sequence of characters used to indicate readiness to accept commands. - :return: Command output. + :returns: Command output. .. warning:: Interruptingcow is used here, and it uses signal(SIGALRM) to let the operating system interrupt program @@ -310,11 +346,12 @@ class SSH(object): 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() - def scp(self, local_path, remote_path, get=False, timeout=10): + def scp(self, local_path, remote_path, get=False, timeout=30, + wildcard=False): """Copy files from local_path to remote_path or vice versa. connect() method has to be called first! @@ -325,10 +362,12 @@ class SSH(object): path to remote file which should be downloaded. :param get: scp operation to perform. Default is put. :param timeout: Timeout value in seconds. + :param wildcard: If path has wildcard characters. Default is false. :type local_path: str :type remote_path: str :type get: bool :type timeout: int + :type wildcard: bool """ if not get: logger.trace('SCP {0} to {1}:{2}'.format( @@ -339,7 +378,11 @@ class SSH(object): self._ssh.get_transport().getpeername(), remote_path, local_path)) # SCPCLient takes a paramiko transport as its only argument - scp = SCPClient(self._ssh.get_transport(), socket_timeout=timeout) + if not wildcard: + scp = SCPClient(self._ssh.get_transport(), socket_timeout=timeout) + else: + scp = SCPClient(self._ssh.get_transport(), sanitize=lambda x: x, + socket_timeout=timeout) start = time() if not get: scp.put(local_path, remote_path) @@ -350,23 +393,61 @@ class SSH(object): 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') if cmd is None: raise TypeError('Command parameter is None') - if len(cmd) == 0: + if not cmd: 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: @@ -376,20 +457,88 @@ def exec_cmd(node, cmd, timeout=600, sudo=False): (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): +def exec_cmd_no_error( + node, cmd, timeout=600, sudo=False, message=None, disconnect=False, + retries=0): """Convenience function to ssh/exec/return out & err. Verifies that return code is zero. - - Returns (stdout, stderr). + 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. + :type node: dict + :type cmd: str or OptionString + :type timeout: int + :type sudo: bool + :type message: str + :type disconnect: bool + :type retries: int + :returns: Stdout, Stderr. + :rtype: tuple(str, str) + :raises RuntimeError: If bash return code is not 0. """ - (ret_code, stdout, stderr) = exec_cmd(node, cmd, timeout=timeout, sudo=sudo) - assert_equal(ret_code, 0, 'Command execution failed: "{}"\n{}'. - format(cmd, stderr)) + 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}"\n{stderr}'. + format(cmd=cmd, stderr=stderr) if message is None else 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: + raise RuntimeError('Failed to connect to {host}!' + .format(host=node['host'])) + try: + ssh.scp(local_path, remote_path, get, timeout) + except SCPException: + raise RuntimeError('SCP execution failed on {host}!' + .format(host=node['host'])) + finally: + if disconnect: + ssh.disconnect()