# (c) 2012-2014, Michael DeHaan # (c) 2015 Toshio Kuratomi # (c) 2017, Peter Sprygada # (c) 2017 Ansible Project from __future__ import (absolute_import, division, print_function) __metaclass__ = type import fcntl import os import shlex import typing as t from abc import abstractmethod from functools import wraps from ansible import constants as C from ansible.module_utils._text import to_bytes, to_text from ansible.plugins import AnsiblePlugin from ansible.utils.display import Display from ansible.plugins.loader import connection_loader, get_shell_plugin from ansible.utils.path import unfrackpath display = Display() __all__ = ['ConnectionBase', 'ensure_connect'] BUFSIZE = 65536 def ensure_connect(func): @wraps(func) def wrapped(self, *args, **kwargs): if not self._connected: self._connect() return func(self, *args, **kwargs) return wrapped class ConnectionBase(AnsiblePlugin): ''' A base class for connections to contain common code. ''' has_pipelining = False has_native_async = False # eg, winrm always_pipeline_modules = False # eg, winrm has_tty = True # for interacting with become plugins # When running over this connection type, prefer modules written in a certain language # as discovered by the specified file extension. An empty string as the # language means any language. module_implementation_preferences = ('',) # type: t.Iterable[str] allow_executable = True # the following control whether or not the connection supports the # persistent connection framework or not supports_persistence = False force_persistence = False default_user = None def __init__(self, play_context, new_stdin, shell=None, *args, **kwargs): super(ConnectionBase, self).__init__() # All these hasattrs allow subclasses to override these parameters if not hasattr(self, '_play_context'): # Backwards compat: self._play_context isn't really needed, using set_options/get_option self._play_context = play_context if not hasattr(self, '_new_stdin'): self._new_stdin = new_stdin if not hasattr(self, '_display'): # Backwards compat: self._display isn't really needed, just import the global display and use that. self._display = display if not hasattr(self, '_connected'): self._connected = False self.success_key = None self.prompt = None self._connected = False self._socket_path = None # helper plugins self._shell = shell # we always must have shell if not self._shell: shell_type = play_context.shell if play_context.shell else getattr(self, '_shell_type', None) self._shell = get_shell_plugin(shell_type=shell_type, executable=self._play_context.executable) self.become = None def set_become_plugin(self, plugin): self.become = plugin @property def connected(self): '''Read-only property holding whether the connection to the remote host is active or closed.''' return self._connected @property def socket_path(self): '''Read-only property holding the connection socket path for this remote host''' return self._socket_path @staticmethod def _split_ssh_args(argstring): """ Takes a string like '-o Foo=1 -o Bar="foo bar"' and returns a list ['-o', 'Foo=1', '-o', 'Bar=foo bar'] that can be added to the argument list. The list will not contain any empty elements. """ # In Python3, shlex.split doesn't work on a byte string. return [to_text(x.strip()) for x in shlex.split(argstring) if x.strip()] @property @abstractmethod def transport(self): """String used to identify this Connection class from other classes""" pass @abstractmethod def _connect(self): """Connect to the host we've been initialized with""" @ensure_connect @abstractmethod def exec_command(self, cmd, in_data=None, sudoable=True): """Run a command on the remote host. :arg cmd: byte string containing the command :kwarg in_data: If set, this data is passed to the command's stdin. This is used to implement pipelining. Currently not all connection plugins implement pipelining. :kwarg sudoable: Tell the connection plugin if we're executing a command via a privilege escalation mechanism. This may affect how the connection plugin returns data. Note that not all connections can handle privilege escalation. :returns: a tuple of (return code, stdout, stderr) The return code is an int while stdout and stderr are both byte strings. When a command is executed, it goes through multiple commands to get there. It looks approximately like this:: [LocalShell] ConnectionCommand [UsersLoginShell (*)] ANSIBLE_SHELL_EXECUTABLE [(BecomeCommand ANSIBLE_SHELL_EXECUTABLE)] Command :LocalShell: Is optional. It is run locally to invoke the ``Connection Command``. In most instances, the ``ConnectionCommand`` can be invoked directly instead. The ssh connection plugin which can have values that need expanding locally specified via ssh_args is the sole known exception to this. Shell metacharacters in the command itself should be processed on the remote machine, not on the local machine so no shell is needed on the local machine. (Example, ``/bin/sh``) :ConnectionCommand: This is the command that connects us to the remote machine to run the rest of the command. ``ansible_user``, ``ansible_ssh_host`` and so forth are fed to this piece of the command to connect to the correct host (Examples ``ssh``, ``chroot``) :UsersLoginShell: This shell may or may not be created depending on the ConnectionCommand used by the connection plugin. This is the shell that the ``ansible_user`` has configured as their login shell. In traditional UNIX parlance, this is the last field of a user's ``/etc/passwd`` entry We do not specifically try to run the ``UsersLoginShell`` when we connect. Instead it is implicit in the actions that the ``ConnectionCommand`` takes when it connects to a remote machine. ``ansible_shell_type`` may be set to inform ansible of differences in how the ``UsersLoginShell`` handles things like quoting if a shell has different semantics than the Bourne shell. :ANSIBLE_SHELL_EXECUTABLE: This is the shell set via the inventory var ``ansible_shell_executable`` or via ``constants.DEFAULT_EXECUTABLE`` if the inventory var is not set. We explicitly invoke this shell so that we have predictable quoting rules at this point. ``ANSIBLE_SHELL_EXECUTABLE`` is only settable by the user because some sudo setups may only allow invoking a specific shell. (For instance, ``/bin/bash`` may be allowed but ``/bin/sh``, our default, may not). We invoke this twice, once after the ``ConnectionCommand`` and once after the ``BecomeCommand``. After the ConnectionCommand, this is run by the ``UsersLoginShell``. After the ``BecomeCommand`` we specify that the ``ANSIBLE_SHELL_EXECUTABLE`` is being invoked directly. :BecomeComand ANSIBLE_SHELL_EXECUTABLE: Is the command that performs privilege escalation. Setting this up is performed by the action plugin prior to running ``exec_command``. So we just get passed :param:`cmd` which has the BecomeCommand already added. (Examples: sudo, su) If we have a BecomeCommand then we will invoke a ANSIBLE_SHELL_EXECUTABLE shell inside of it so that we have a consistent view of quoting. :Command: Is the command we're actually trying to run remotely. (Examples: mkdir -p $HOME/.ansible, python $HOME/.ansible/tmp-script-file) """ pass @ensure_connect @abstractmethod def put_file(self, in_path, out_path): """Transfer a file from local to remote""" pass @ensure_connect @abstractmethod def fetch_file(self, in_path, out_path): """Fetch a file from remote to local; callers are expected to have pre-created the directory chain for out_path""" pass @abstractmethod def close(self): """Terminate the connection""" pass def connection_lock(self): f = self._play_context.connection_lockfd display.vvvv('CONNECTION: pid %d waiting for lock on %d' % (os.getpid(), f), host=self._play_context.remote_addr) fcntl.lockf(f, fcntl.LOCK_EX) display.vvvv('CONNECTION: pid %d acquired lock on %d' % (os.getpid(), f), host=self._play_context.remote_addr) def connection_unlock(self): f = self._play_context.connection_lockfd fcntl.lockf(f, fcntl.LOCK_UN) display.vvvv('CONNECTION: pid %d released lock on %d' % (os.getpid(), f), host=self._play_context.remote_addr) def reset(self): display.warning("Reset is not implemented for this connection") def update_vars(self, variables): ''' Adds 'magic' variables relating to connections to the variable dictionary provided. In case users need to access from the play, this is a legacy from runner. ''' for varname in C.COMMON_CONNECTION_VARS: value = None if varname in variables: # dont update existing continue elif 'password' in varname or 'passwd' in varname: # no secrets! continue elif varname == 'ansible_connection': # its me mom! value = self._load_name elif varname == 'ansible_shell_type': # its my cousin ... value = self._shell._load_name else: # deal with generic options if the plugin supports em (for exmaple not all connections have a remote user) options = C.config.get_plugin_options_from_var('connection', self._load_name, varname) if options: value = self.get_option(options[0]) # for these variables there should be only one option elif 'become' not in varname: # fallback to play_context, unles becoem related TODO: in the end should come from task/play and not pc for prop, var_list in C.MAGIC_VARIABLE_MAPPING.items(): if varname in var_list: try: value = getattr(self._play_context, prop) break except AttributeError: # it was not defined, fine to ignore continue if value is not None: display.debug('Set connection var {0} to {1}'.format(varname, value)) variables[varname] = value class NetworkConnectionBase(ConnectionBase): """ A base class for network-style connections. """ force_persistence = True # Do not use _remote_is_local in other connections _remote_is_local = True def __init__(self, play_context, new_stdin, *args, **kwargs): super(NetworkConnectionBase, self).__init__(play_context, new_stdin, *args, **kwargs) self._messages = [] self._conn_closed = False self._network_os = self._play_context.network_os self._local = connection_loader.get('local', play_context, '/dev/null') self._local.set_options() self._sub_plugin = {} self._cached_variables = (None, None, None) # reconstruct the socket_path and set instance values accordingly self._ansible_playbook_pid = kwargs.get('ansible_playbook_pid') self._update_connection_state() def __getattr__(self, name): try: return self.__dict__[name] except KeyError: if not name.startswith('_'): plugin = self._sub_plugin.get('obj') if plugin: method = getattr(plugin, name, None) if method is not None: return method raise AttributeError("'%s' object has no attribute '%s'" % (self.__class__.__name__, name)) def exec_command(self, cmd, in_data=None, sudoable=True): return self._local.exec_command(cmd, in_data, sudoable) def queue_message(self, level, message): """ Adds a message to the queue of messages waiting to be pushed back to the controller process. :arg level: A string which can either be the name of a method in display, or 'log'. When the messages are returned to task_executor, a value of log will correspond to ``display.display(message, log_only=True)``, while another value will call ``display.[level](message)`` """ self._messages.append((level, message)) def pop_messages(self): messages, self._messages = self._messages, [] return messages def put_file(self, in_path, out_path): """Transfer a file from local to remote""" return self._local.put_file(in_path, out_path) def fetch_file(self, in_path, out_path): """Fetch a file from remote to local""" return self._local.fetch_file(in_path, out_path) def reset(self): ''' Reset the connection ''' if self._socket_path: self.queue_message('vvvv', 'resetting persistent connection for socket_path %s' % self._socket_path) self.close() self.queue_message('vvvv', 'reset call on connection instance') def close(self): self._conn_closed = True if self._connected: self._connected = False def set_options(self, task_keys=None, var_options=None, direct=None): super(NetworkConnectionBase, self).set_options(task_keys=task_keys, var_options=var_options, direct=direct) if self.get_option('persistent_log_messages'): warning = "Persistent connection logging is enabled for %s. This will log ALL interactions" % self._play_context.remote_addr logpath = getattr(C, 'DEFAULT_LOG_PATH') if logpath is not None: warning += " to %s" % logpath self.queue_message('warning', "%s and WILL NOT redact sensitive configuration like passwords. USE WITH CAUTION!" % warning) if self._sub_plugin.get('obj') and self._sub_plugin.get('type') != 'external': try: self._sub_plugin['obj'].set_options(task_keys=task_keys, var_options=var_options, direct=direct) except AttributeError: pass def _update_connection_state(self): ''' Reconstruct the connection socket_path and check if it exists If the socket path exists then the connection is active and set both the _socket_path value to the path and the _connected value to True. If the socket path doesn't exist, leave the socket path value to None and the _connected value to False ''' ssh = connection_loader.get('ssh', class_only=True) control_path = ssh._create_control_path( self._play_context.remote_addr, self._play_context.port, self._play_context.remote_user, self._play_context.connection, self._ansible_playbook_pid ) tmp_path = unfrackpath(C.PERSISTENT_CONTROL_PATH_DIR) socket_path = unfrackpath(control_path % dict(directory=tmp_path)) if os.path.exists(socket_path): self._connected = True self._socket_path = socket_path def _log_messages(self, message): if self.get_option('persistent_log_messages'): self.queue_message('log', message)