# (c) 2016 Red Hat Inc. # (c) 2017 Ansible Project # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt) from __future__ import (absolute_import, division, print_function) __metaclass__ = type DOCUMENTATION = """ --- author: Ansible Networking Team connection: network_cli short_description: Use network_cli to run command on network appliances description: - This connection plugin provides a connection to remote devices over the SSH and implements a CLI shell. This connection plugin is typically used by network devices for sending and receiving CLi commands to network devices. version_added: "2.3" options: host: description: - Specifies the remote device FQDN or IP address to establish the SSH connection to. default: inventory_hostname vars: - name: ansible_host port: type: int description: - Specifies the port on the remote device that listens for connections when establishing the SSH connection. default: 22 ini: - section: defaults key: remote_port env: - name: ANSIBLE_REMOTE_PORT vars: - name: ansible_port network_os: description: - Configures the device platform network operating system. This value is used to load the correct terminal and cliconf plugins to communicate with the remote device. vars: - name: ansible_network_os remote_user: description: - The username used to authenticate to the remote device when the SSH connection is first established. If the remote_user is not specified, the connection will use the username of the logged in user. - Can be configured from the CLI via the C(--user) or C(-u) options. ini: - section: defaults key: remote_user env: - name: ANSIBLE_REMOTE_USER vars: - name: ansible_user password: description: - Configures the user password used to authenticate to the remote device when first establishing the SSH connection. vars: - name: ansible_password - name: ansible_ssh_pass - name: ansible_ssh_password private_key_file: description: - The private SSH key or certificate file used to authenticate to the remote device when first establishing the SSH connection. ini: - section: defaults key: private_key_file env: - name: ANSIBLE_PRIVATE_KEY_FILE vars: - name: ansible_private_key_file become: type: boolean description: - The become option will instruct the CLI session to attempt privilege escalation on platforms that support it. Normally this means transitioning from user mode to C(enable) mode in the CLI session. If become is set to True and the remote device does not support privilege escalation or the privilege has already been elevated, then this option is silently ignored. - Can be configured from the CLI via the C(--become) or C(-b) options. default: False ini: - section: privilege_escalation key: become env: - name: ANSIBLE_BECOME vars: - name: ansible_become become_method: description: - This option allows the become method to be specified in for handling privilege escalation. Typically the become_method value is set to C(enable) but could be defined as other values. default: sudo ini: - section: privilege_escalation key: become_method env: - name: ANSIBLE_BECOME_METHOD vars: - name: ansible_become_method host_key_auto_add: type: boolean description: - By default, Ansible will prompt the user before adding SSH keys to the known hosts file. Since persistent connections such as network_cli run in background processes, the user will never be prompted. By enabling this option, unknown host keys will automatically be added to the known hosts file. - Be sure to fully understand the security implications of enabling this option on production systems as it could create a security vulnerability. default: False ini: - section: paramiko_connection key: host_key_auto_add env: - name: ANSIBLE_HOST_KEY_AUTO_ADD persistent_connect_timeout: type: int description: - Configures, in seconds, the amount of time to wait when trying to initially establish a persistent connection. If this value expires before the connection to the remote device is completed, the connection will fail. default: 30 ini: - section: persistent_connection key: connect_timeout env: - name: ANSIBLE_PERSISTENT_CONNECT_TIMEOUT vars: - name: ansible_connect_timeout persistent_command_timeout: type: int description: - Configures, in seconds, the amount of time to wait for a command to return from the remote device. If this timer is exceeded before the command returns, the connection plugin will raise an exception and close. default: 30 ini: - section: persistent_connection key: command_timeout env: - name: ANSIBLE_PERSISTENT_COMMAND_TIMEOUT vars: - name: ansible_command_timeout persistent_buffer_read_timeout: type: float description: - Configures, in seconds, the amount of time to wait for the data to be read from Paramiko channel after the command prompt is matched. This timeout value ensures that command prompt matched is correct and there is no more data left to be received from remote host. default: 0.1 ini: - section: persistent_connection key: buffer_read_timeout env: - name: ANSIBLE_PERSISTENT_BUFFER_READ_TIMEOUT vars: - name: ansible_buffer_read_timeout persistent_log_messages: type: boolean description: - This flag will enable logging the command executed and response received from target device in the ansible log file. For this option to work 'log_path' ansible configuration option is required to be set to a file path with write access. - Be sure to fully understand the security implications of enabling this option as it could create a security vulnerability by logging sensitive information in log file. default: False ini: - section: persistent_connection key: log_messages env: - name: ANSIBLE_PERSISTENT_LOG_MESSAGES vars: - name: ansible_persistent_log_messages terminal_stdout_re: type: list elements: dict version_added: '2.9' description: - A single regex pattern or a sequence of patterns along with optional flags to match the command prompt from the received response chunk. This option accepts C(pattern) and C(flags) keys. The value of C(pattern) is a python regex pattern to match the response and the value of C(flags) is the value accepted by I(flags) argument of I(re.compile) python method to control the way regex is matched with the response, for example I('re.I'). vars: - name: ansible_terminal_stdout_re terminal_stderr_re: type: list elements: dict version_added: '2.9' description: - This option provides the regex pattern and optional flags to match the error string from the received response chunk. This option accepts C(pattern) and C(flags) keys. The value of C(pattern) is a python regex pattern to match the response and the value of C(flags) is the value accepted by I(flags) argument of I(re.compile) python method to control the way regex is matched with the response, for example I('re.I'). vars: - name: ansible_terminal_stderr_re terminal_initial_prompt: type: list version_added: '2.9' description: - A single regex pattern or a sequence of patterns to evaluate the expected prompt at the time of initial login to the remote host. vars: - name: ansible_terminal_initial_prompt terminal_initial_answer: type: list version_added: '2.9' description: - The answer to reply with if the C(terminal_initial_prompt) is matched. The value can be a single answer or a list of answers for multiple terminal_initial_prompt. In case the login menu has multiple prompts the sequence of the prompt and excepted answer should be in same order and the value of I(terminal_prompt_checkall) should be set to I(True) if all the values in C(terminal_initial_prompt) are expected to be matched and set to I(False) if any one login prompt is to be matched. vars: - name: ansible_terminal_initial_answer terminal_initial_prompt_checkall: type: boolean version_added: '2.9' description: - By default the value is set to I(False) and any one of the prompts mentioned in C(terminal_initial_prompt) option is matched it won't check for other prompts. When set to I(True) it will check for all the prompts mentioned in C(terminal_initial_prompt) option in the given order and all the prompts should be received from remote host if not it will result in timeout. default: False vars: - name: ansible_terminal_initial_prompt_checkall terminal_inital_prompt_newline: type: boolean version_added: '2.9' description: - This boolean flag, that when set to I(True) will send newline in the response if any of values in I(terminal_initial_prompt) is matched. default: True vars: - name: ansible_terminal_initial_prompt_newline network_cli_retries: description: - Number of attempts to connect to remote host. The delay time between the retires increases after every attempt by power of 2 in seconds till either the maximum attempts are exhausted or any of the C(persistent_command_timeout) or C(persistent_connect_timeout) timers are triggered. default: 3 version_added: '2.9' type: integer env: - name: ANSIBLE_NETWORK_CLI_RETRIES ini: - section: persistent_connection key: network_cli_retries vars: - name: ansible_network_cli_retries """ from functools import wraps import getpass import json import logging import re import os import signal import socket import time import traceback from io import BytesIO from ansible.errors import AnsibleConnectionFailure from ansible.module_utils.six import PY3 from ansible.module_utils.six.moves import cPickle from ansible.module_utils.network.common.utils import to_list from ansible.module_utils._text import to_bytes, to_text from ansible.playbook.play_context import PlayContext from ansible.plugins.connection import NetworkConnectionBase from ansible.plugins.loader import cliconf_loader, terminal_loader, connection_loader def ensure_connect(func): @wraps(func) def wrapped(self, *args, **kwargs): if not self._connected: self._connect() self.update_cli_prompt_context() return func(self, *args, **kwargs) return wrapped class AnsibleCmdRespRecv(Exception): pass class Connection(NetworkConnectionBase): ''' CLI (shell) SSH connections on Paramiko ''' transport = 'network_cli' has_pipelining = True def __init__(self, play_context, new_stdin, *args, **kwargs): super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs) self._ssh_shell = None self._matched_prompt = None self._matched_cmd_prompt = None self._matched_pattern = None self._last_response = None self._history = list() self._command_response = None self._last_recv_window = None self._terminal = None self.cliconf = None self._paramiko_conn = None # Managing prompt context self._check_prompt = False self._task_uuid = to_text(kwargs.get('task_uuid', '')) if self._play_context.verbosity > 3: logging.getLogger('paramiko').setLevel(logging.DEBUG) if self._network_os: self._terminal = terminal_loader.get(self._network_os, self) if not self._terminal: raise AnsibleConnectionFailure('network os %s is not supported' % self._network_os) self.cliconf = cliconf_loader.get(self._network_os, self) if self.cliconf: self._sub_plugin = {'type': 'cliconf', 'name': self.cliconf._load_name, 'obj': self.cliconf} self.queue_message('vvvv', 'loaded cliconf plugin %s from path %s for network_os %s' % (self.cliconf._load_name, self.cliconf._original_path, self._network_os)) else: self.queue_message('vvvv', 'unable to load cliconf for network_os %s' % self._network_os) else: raise AnsibleConnectionFailure( 'Unable to automatically determine host network os. Please ' 'manually configure ansible_network_os value for this host' ) self.queue_message('log', 'network_os is set to %s' % self._network_os) @property def paramiko_conn(self): if self._paramiko_conn is None: self._paramiko_conn = connection_loader.get('paramiko', self._play_context, '/dev/null') self._paramiko_conn.set_options(direct={'look_for_keys': not bool(self._play_context.password and not self._play_context.private_key_file)}) return self._paramiko_conn def _get_log_channel(self): name = "p=%s u=%s | " % (os.getpid(), getpass.getuser()) name += "paramiko [%s]" % self._play_context.remote_addr return name @ensure_connect def get_prompt(self): """Returns the current prompt from the device""" return self._matched_prompt def exec_command(self, cmd, in_data=None, sudoable=True): # this try..except block is just to handle the transition to supporting # network_cli as a toplevel connection. Once connection=local is gone, # this block can be removed as well and all calls passed directly to # the local connection if self._ssh_shell: try: cmd = json.loads(to_text(cmd, errors='surrogate_or_strict')) kwargs = {'command': to_bytes(cmd['command'], errors='surrogate_or_strict')} for key in ('prompt', 'answer', 'sendonly', 'newline', 'prompt_retry_check'): if cmd.get(key) is True or cmd.get(key) is False: kwargs[key] = cmd[key] elif cmd.get(key) is not None: kwargs[key] = to_bytes(cmd[key], errors='surrogate_or_strict') return self.send(**kwargs) except ValueError: cmd = to_bytes(cmd, errors='surrogate_or_strict') return self.send(command=cmd) else: return super(Connection, self).exec_command(cmd, in_data, sudoable) def update_play_context(self, pc_data): """Updates the play context information for the connection""" pc_data = to_bytes(pc_data) if PY3: pc_data = cPickle.loads(pc_data, encoding='bytes') else: pc_data = cPickle.loads(pc_data) play_context = PlayContext() play_context.deserialize(pc_data) self.queue_message('vvvv', 'updating play_context for connection') if self._play_context.become ^ play_context.become: if play_context.become is True: auth_pass = play_context.become_pass self._terminal.on_become(passwd=auth_pass) self.queue_message('vvvv', 'authorizing connection') else: self._terminal.on_unbecome() self.queue_message('vvvv', 'deauthorizing connection') self._play_context = play_context if hasattr(self, 'reset_history'): self.reset_history() if hasattr(self, 'disable_response_logging'): self.disable_response_logging() def set_check_prompt(self, task_uuid): self._check_prompt = task_uuid def update_cli_prompt_context(self): # set cli prompt context at the start of new task run only if self._check_prompt and self._task_uuid != self._check_prompt: self._task_uuid, self._check_prompt = self._check_prompt, False self.set_cli_prompt_context() def _connect(self): ''' Connects to the remote device and starts the terminal ''' if not self.connected: self.paramiko_conn._set_log_channel(self._get_log_channel()) self.paramiko_conn.force_persistence = self.force_persistence command_timeout = self.get_option('persistent_command_timeout') max_pause = min([self.get_option('persistent_connect_timeout'), command_timeout]) retries = self.get_option('network_cli_retries') total_pause = 0 for attempt in range(retries + 1): try: ssh = self.paramiko_conn._connect() break except Exception as e: pause = 2 ** (attempt + 1) if attempt == retries or total_pause >= max_pause: raise AnsibleConnectionFailure(to_text(e, errors='surrogate_or_strict')) else: msg = (u"network_cli_retry: attempt: %d, caught exception(%s), " u"pausing for %d seconds" % (attempt + 1, to_text(e, errors='surrogate_or_strict'), pause)) self.queue_message('vv', msg) time.sleep(pause) total_pause += pause continue self.queue_message('vvvv', 'ssh connection done, setting terminal') self._connected = True self._ssh_shell = ssh.ssh.invoke_shell() self._ssh_shell.settimeout(command_timeout) self.queue_message('vvvv', 'loaded terminal plugin for network_os %s' % self._network_os) terminal_initial_prompt = self.get_option('terminal_initial_prompt') or self._terminal.terminal_initial_prompt terminal_initial_answer = self.get_option('terminal_initial_answer') or self._terminal.terminal_initial_answer newline = self.get_option('terminal_inital_prompt_newline') or self._terminal.terminal_inital_prompt_newline check_all = self.get_option('terminal_initial_prompt_checkall') or False self.receive(prompts=terminal_initial_prompt, answer=terminal_initial_answer, newline=newline, check_all=check_all) if self._play_context.become: self.queue_message('vvvv', 'firing event: on_become') auth_pass = self._play_context.become_pass self._terminal.on_become(passwd=auth_pass) self.queue_message('vvvv', 'firing event: on_open_shell()') self._terminal.on_open_shell() self.queue_message('vvvv', 'ssh connection has completed successfully') return self def close(self): ''' Close the active connection to the device ''' # only close the connection if its connected. if self._connected: self.queue_message('debug', "closing ssh connection to device") if self._ssh_shell: self.queue_message('debug', "firing event: on_close_shell()") self._terminal.on_close_shell() self._ssh_shell.close() self._ssh_shell = None self.queue_message('debug', "cli session is now closed") self.paramiko_conn.close() self._paramiko_conn = None self.queue_message('debug', "ssh connection has been closed successfully") super(Connection, self).close() def receive(self, command=None, prompts=None, answer=None, newline=True, prompt_retry_check=False, check_all=False): ''' Handles receiving of output from command ''' self._matched_prompt = None self._matched_cmd_prompt = None recv = BytesIO() handled = False command_prompt_matched = False matched_prompt_window = window_count = 0 # set terminal regex values for command prompt and errors in response self._terminal_stderr_re = self._get_terminal_std_re('terminal_stderr_re') self._terminal_stdout_re = self._get_terminal_std_re('terminal_stdout_re') cache_socket_timeout = self._ssh_shell.gettimeout() command_timeout = self.get_option('persistent_command_timeout') self._validate_timeout_value(command_timeout, "persistent_command_timeout") if cache_socket_timeout != command_timeout: self._ssh_shell.settimeout(command_timeout) buffer_read_timeout = self.get_option('persistent_buffer_read_timeout') self._validate_timeout_value(buffer_read_timeout, "persistent_buffer_read_timeout") self._log_messages("command: %s" % command) while True: if command_prompt_matched: try: signal.signal(signal.SIGALRM, self._handle_buffer_read_timeout) signal.setitimer(signal.ITIMER_REAL, buffer_read_timeout) data = self._ssh_shell.recv(256) signal.alarm(0) self._log_messages("response-%s: %s" % (window_count + 1, data)) # if data is still received on channel it indicates the prompt string # is wrongly matched in between response chunks, continue to read # remaining response. command_prompt_matched = False # restart command_timeout timer signal.signal(signal.SIGALRM, self._handle_command_timeout) signal.alarm(command_timeout) except AnsibleCmdRespRecv: # reset socket timeout to global timeout self._ssh_shell.settimeout(cache_socket_timeout) return self._command_response else: data = self._ssh_shell.recv(256) self._log_messages("response-%s: %s" % (window_count + 1, data)) # when a channel stream is closed, received data will be empty if not data: break recv.write(data) offset = recv.tell() - 256 if recv.tell() > 256 else 0 recv.seek(offset) window = self._strip(recv.read()) self._last_recv_window = window window_count += 1 if prompts and not handled: handled = self._handle_prompt(window, prompts, answer, newline, False, check_all) matched_prompt_window = window_count elif prompts and handled and prompt_retry_check and matched_prompt_window + 1 == window_count: # check again even when handled, if same prompt repeats in next window # (like in the case of a wrong enable password, etc) indicates # value of answer is wrong, report this as error. if self._handle_prompt(window, prompts, answer, newline, prompt_retry_check, check_all): raise AnsibleConnectionFailure("For matched prompt '%s', answer is not valid" % self._matched_cmd_prompt) if self._find_prompt(window): self._last_response = recv.getvalue() resp = self._strip(self._last_response) self._command_response = self._sanitize(resp, command) if buffer_read_timeout == 0.0: # reset socket timeout to global timeout self._ssh_shell.settimeout(cache_socket_timeout) return self._command_response else: command_prompt_matched = True @ensure_connect def send(self, command, prompt=None, answer=None, newline=True, sendonly=False, prompt_retry_check=False, check_all=False): ''' Sends the command to the device in the opened shell ''' if check_all: prompt_len = len(to_list(prompt)) answer_len = len(to_list(answer)) if prompt_len != answer_len: raise AnsibleConnectionFailure("Number of prompts (%s) is not same as that of answers (%s)" % (prompt_len, answer_len)) try: cmd = b'%s\r' % command self._history.append(cmd) self._ssh_shell.sendall(cmd) self._log_messages('send command: %s' % cmd) if sendonly: return response = self.receive(command, prompt, answer, newline, prompt_retry_check, check_all) return to_text(response, errors='surrogate_then_replace') except (socket.timeout, AttributeError): self.queue_message('error', traceback.format_exc()) raise AnsibleConnectionFailure("timeout value %s seconds reached while trying to send command: %s" % (self._ssh_shell.gettimeout(), command.strip())) def _handle_buffer_read_timeout(self, signum, frame): self.queue_message('vvvv', "Response received, triggered 'persistent_buffer_read_timeout' timer of %s seconds" % self.get_option('persistent_buffer_read_timeout')) raise AnsibleCmdRespRecv() def _handle_command_timeout(self, signum, frame): msg = 'command timeout triggered, timeout value is %s secs.\nSee the timeout setting options in the Network Debug and Troubleshooting Guide.'\ % self.get_option('persistent_command_timeout') self.queue_message('log', msg) raise AnsibleConnectionFailure(msg) def _strip(self, data): ''' Removes ANSI codes from device response ''' for regex in self._terminal.ansi_re: data = regex.sub(b'', data) return data def _handle_prompt(self, resp, prompts, answer, newline, prompt_retry_check=False, check_all=False): ''' Matches the command prompt and responds :arg resp: Byte string containing the raw response from the remote :arg prompts: Sequence of byte strings that we consider prompts for input :arg answer: Sequence of Byte string to send back to the remote if we find a prompt. A carriage return is automatically appended to this string. :param prompt_retry_check: Bool value for trying to detect more prompts :param check_all: Bool value to indicate if all the values in prompt sequence should be matched or any one of given prompt. :returns: True if a prompt was found in ``resp``. If check_all is True will True only after all the prompt in the prompts list are matched. False otherwise. ''' single_prompt = False if not isinstance(prompts, list): prompts = [prompts] single_prompt = True if not isinstance(answer, list): answer = [answer] prompts_regex = [re.compile(to_bytes(r), re.I) for r in prompts] for index, regex in enumerate(prompts_regex): match = regex.search(resp) if match: self._matched_cmd_prompt = match.group() self._log_messages("matched command prompt: %s" % self._matched_cmd_prompt) # if prompt_retry_check is enabled to check if same prompt is # repeated don't send answer again. if not prompt_retry_check: prompt_answer = answer[index] if len(answer) > index else answer[0] self._ssh_shell.sendall(b'%s' % prompt_answer) if newline: self._ssh_shell.sendall(b'\r') prompt_answer += b'\r' self._log_messages("matched command prompt answer: %s" % prompt_answer) if check_all and prompts and not single_prompt: prompts.pop(0) answer.pop(0) return False return True return False def _sanitize(self, resp, command=None): ''' Removes elements from the response before returning to the caller ''' cleaned = [] for line in resp.splitlines(): if command and line.strip() == command.strip(): continue for prompt in self._matched_prompt.strip().splitlines(): if prompt.strip() in line: break else: cleaned.append(line) return b'\n'.join(cleaned).strip() def _find_prompt(self, response): '''Searches the buffered response for a matching command prompt ''' errored_response = None is_error_message = False for regex in self._terminal_stderr_re: if regex.search(response): is_error_message = True # Check if error response ends with command prompt if not # receive it buffered prompt for regex in self._terminal_stdout_re: match = regex.search(response) if match: errored_response = response self._matched_pattern = regex.pattern self._matched_prompt = match.group() self._log_messages("matched error regex '%s' from response '%s'" % (self._matched_pattern, errored_response)) break if not is_error_message: for regex in self._terminal_stdout_re: match = regex.search(response) if match: self._matched_pattern = regex.pattern self._matched_prompt = match.group() self._log_messages("matched cli prompt '%s' with regex '%s' from response '%s'" % (self._matched_prompt, self._matched_pattern, response)) if not errored_response: return True if errored_response: raise AnsibleConnectionFailure(errored_response) return False def _validate_timeout_value(self, timeout, timer_name): if timeout < 0: raise AnsibleConnectionFailure("'%s' timer value '%s' is invalid, value should be greater than or equal to zero." % (timer_name, timeout)) def transport_test(self, connect_timeout): """This method enables wait_for_connection to work. As it is used by wait_for_connection, it is called by that module's action plugin, which is on the controller process, which means that nothing done on this instance should impact the actual persistent connection... this check is for informational purposes only and should be properly cleaned up. """ # Force a fresh connect if for some reason we have connected before. self.close() self._connect() self.close() def _get_terminal_std_re(self, option): terminal_std_option = self.get_option(option) terminal_std_re = [] if terminal_std_option: for item in terminal_std_option: if "pattern" not in item: raise AnsibleConnectionFailure("'pattern' is a required key for option '%s'," " received option value is %s" % (option, item)) pattern = br"%s" % to_bytes(item['pattern']) flag = item.get('flags', 0) if flag: flag = getattr(re, flag.split('.')[1]) terminal_std_re.append(re.compile(pattern, flag)) else: # To maintain backward compatibility terminal_std_re = getattr(self._terminal, option) return terminal_std_re