# (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 to listening 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 form 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 private_key_file: description: - The private SSH key or certificate file used to 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 timeout: type: int description: - Sets the connection time, in seconds, for the communicating with the remote device. This timeout is used as the default timeout value for commands when issuing a command to the network CLI. If the command does not return in timeout seconds, the an error is generated. default: 120 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 form 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: 10 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 """ import getpass import json import logging import re import os import signal import socket import traceback from ansible.errors import AnsibleConnectionFailure from ansible.module_utils.six import BytesIO, 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 try: from __main__ import display except ImportError: from ansible.utils.display import Display display = Display() 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._terminal = None self.cliconf = None self.paramiko_conn = None if self._play_context.verbosity > 3: logging.getLogger('paramiko').setLevel(logging.DEBUG) def _get_log_channel(self): name = "p=%s u=%s | " % (os.getpid(), getpass.getuser()) name += "paramiko [%s]" % self._play_context.remote_addr return name 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) messages = ['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) messages.append('authorizing connection') else: self._terminal.on_unbecome() messages.append('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() return messages def _connect(self): ''' Connects to the remote device and starts the terminal ''' if not self.connected: if not self._network_os: raise AnsibleConnectionFailure( 'Unable to automatically determine host network os. Please ' 'manually configure ansible_network_os value for this host' ) display.display('network_os is set to %s' % self._network_os, log_only=True) self.paramiko_conn = connection_loader.get('paramiko', self._play_context, '/dev/null') self.paramiko_conn._set_log_channel(self._get_log_channel()) self.paramiko_conn.set_options(direct={'look_for_keys': not bool(self._play_context.password and not self._play_context.private_key_file)}) self.paramiko_conn.force_persistence = self.force_persistence ssh = self.paramiko_conn._connect() host = self.get_option('host') display.vvvv('ssh connection done, setting terminal', host=host) self._ssh_shell = ssh.ssh.invoke_shell() self._ssh_shell.settimeout(self.get_option('persistent_command_timeout')) self._terminal = terminal_loader.get(self._network_os, self) if not self._terminal: raise AnsibleConnectionFailure('network os %s is not supported' % self._network_os) display.vvvv('loaded terminal plugin for network_os %s' % self._network_os, host=host) self.cliconf = cliconf_loader.get(self._network_os, self) if self.cliconf: display.vvvv('loaded cliconf plugin for network_os %s' % self._network_os, host=host) self._implementation_plugins.append(self.cliconf) else: display.vvvv('unable to load cliconf for network_os %s' % self._network_os) super(Connection, self)._connect() self.receive(prompts=self._terminal.terminal_initial_prompt, answer=self._terminal.terminal_initial_answer, newline=self._terminal.terminal_inital_prompt_newline) display.vvvv('firing event: on_open_shell()', host=host) self._terminal.on_open_shell() if self._play_context.become and self._play_context.become_method == 'enable': display.vvvv('firing event: on_become', host=host) auth_pass = self._play_context.become_pass self._terminal.on_become(passwd=auth_pass) display.vvvv('ssh connection has completed successfully', host=host) self._connected = True return self def close(self): ''' Close the active connection to the device ''' # only close the connection if its connected. if self._connected: display.debug("closing ssh connection to device", host=self._play_context.remote_addr) if self._ssh_shell: display.debug("firing event: on_close_shell()") self._terminal.on_close_shell() self._ssh_shell.close() self._ssh_shell = None display.debug("cli session is now closed") self.paramiko_conn.close() self.paramiko_conn = None display.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 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") 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) # 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) # 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()) 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 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: self._history.append(command) self._ssh_shell.sendall(b'%s\r' % command) if sendonly: return response = self.receive(command, prompt, answer, newline, prompt_retry_check, check_all) return to_text(response, errors='surrogate_or_strict') except (socket.timeout, AttributeError): display.vvvv(traceback.format_exc(), host=self._play_context.remote_addr) 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): display.vvvv("Response received, triggered 'persistent_buffer_read_timeout' timer of %s seconds" % self.get_option('persistent_buffer_read_timeout'), host=self._play_context.remote_addr) 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') display.display(msg, log_only=True) 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(r, re.I) for r in prompts] for index, regex in enumerate(prompts_regex): match = regex.search(resp) if match: # 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') self._matched_cmd_prompt = match.group() 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()) or self._matched_prompt.strip() in line: continue 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.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.terminal_stdout_re: match = regex.search(response) if match: errored_response = response self._matched_pattern = regex.pattern self._matched_prompt = match.group() break if not is_error_message: for regex in self._terminal.terminal_stdout_re: match = regex.search(response) if match: self._matched_pattern = regex.pattern self._matched_prompt = match.group() 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))