mitogen/ansible_mitogen/connection.py

410 lines
14 KiB
Python

# Copyright 2017, David Wilson
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its contributors
# may be used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
from __future__ import absolute_import
import logging
import os
import shlex
import sys
import time
import ansible.errors
import ansible.plugins.connection
import mitogen.unix
import mitogen.utils
import ansible_mitogen.target
import ansible_mitogen.process
from ansible_mitogen.services import ContextService
LOG = logging.getLogger(__name__)
class Connection(ansible.plugins.connection.ConnectionBase):
#: mitogen.master.Broker for this worker.
broker = None
#: mitogen.master.Router for this worker.
router = None
#: mitogen.master.Context representing the parent Context, which is
#: presently always the master process.
parent = None
#: mitogen.master.Context connected to the target machine's initial SSH
#: account.
host = None
#: mitogen.master.Context connected to the target user account on the
#: target machine (i.e. via sudo), or simply a copy of :attr:`host` if
#: become is not in use.
context = None
#: Only sudo is supported for now.
become_methods = ['sudo']
#: Set by the constructor according to whichever connection type this
#: connection should emulate. We emulate the original connection type to
#: work around artificial limitations in e.g. the synchronize action, which
#: hard-codes 'local' and 'ssh' as the only allowable connection types.
transport = None
#: Set to 'ansible_python_interpreter' by on_action_run().
python_path = None
#: Set to 'ansible_sudo_exe' by on_action_run().
sudo_path = None
#: Set to 'ansible_ssh_timeout' by on_action_run().
ansible_ssh_timeout = None
#: Set after connection to the target context's home directory.
_homedir = None
def __init__(self, play_context, new_stdin, original_transport, **kwargs):
assert ansible_mitogen.process.MuxProcess.unix_listener_path, (
'The "mitogen" connection plug-in may only be instantiated '
'by the "mitogen" strategy plug-in.'
)
self.original_transport = original_transport
self.transport = original_transport
self.kwargs = kwargs
super(Connection, self).__init__(play_context, new_stdin)
def __del__(self):
"""
Ansible cannot be trusted to always call close() e.g. the synchronize
action constructs a local connection like this. So provide a destructor
in the hopes of catching these cases.
"""
# https://github.com/dw/mitogen/issues/140
self.close()
def on_action_run(self, task_vars):
"""
Invoked by ActionModuleMixin to indicate a new task is about to start
executing. We use the opportunity to grab relevant bits from the
task-specific data.
"""
self.ansible_ssh_timeout = task_vars.get(
'ansible_ssh_timeout',
None
)
self.python_path = task_vars.get(
'ansible_python_interpreter',
'/usr/bin/python'
)
self.sudo_path = task_vars.get(
'ansible_sudo_exe',
'sudo'
)
self.close(new_task=True)
@property
def homedir(self):
self._connect()
return self._homedir
@property
def connected(self):
return self.context is not None
def _on_connection_error(self, msg):
raise ansible.errors.AnsibleConnectionFailure(msg)
def _on_become_error(self, msg):
# TODO: vanilla become failures yield this:
# {
# "changed": false,
# "module_stderr": "sudo: sorry, you must have a tty to run sudo\n",
# "module_stdout": "",
# "msg": "MODULE FAILURE",
# "rc": 1
# }
#
# Currently we yield this:
# {
# "msg": "EOF on stream; last 300 bytes received: 'sudo: ....\n'"
# }
raise ansible.errors.AnsibleModuleError(msg)
def _wrap_connect(self, on_error, kwargs):
dct = mitogen.service.call(
context=self.parent,
handle=ContextService.handle,
method='get',
kwargs=mitogen.utils.cast(kwargs),
)
if dct['msg']:
on_error(dct['msg'])
return dct['context'], dct['home_dir']
def _connect_local(self):
"""
Fetch a reference to the local() Context from ContextService in the
master process.
"""
return self._wrap_connect(self._on_connection_error, {
'method_name': 'local',
'python_path': self.python_path,
})
def _connect_ssh(self):
"""
Fetch a reference to an SSH Context matching the play context from
ContextService in the master process.
"""
return self._wrap_connect(self._on_connection_error, {
'method_name': 'ssh',
'check_host_keys': False, # TODO
'hostname': self._play_context.remote_addr,
'username': self._play_context.remote_user,
'password': self._play_context.password,
'port': self._play_context.port,
'python_path': self.python_path,
'identity_file': self._play_context.private_key_file,
'ssh_path': self._play_context.ssh_executable,
'connect_timeout': self.ansible_ssh_timeout,
'ssh_args': [
term
for s in (
getattr(self._play_context, 'ssh_args', ''),
getattr(self._play_context, 'ssh_common_args', ''),
getattr(self._play_context, 'ssh_extra_args', '')
)
for term in shlex.split(s or '')
]
})
def _connect_docker(self):
return self._wrap_connect(self._on_connection_error, {
'method_name': 'docker',
'container': self._play_context.remote_addr,
'python_path': self.python_path,
'connect_timeout': self._play_context.timeout,
})
def _connect_sudo(self, via=None, python_path=None):
"""
Fetch a reference to a sudo Context matching the play context from
ContextService in the master process.
:param via:
Parent Context of the sudo Context. For Ansible, this should always
be a Context returned by _connect_ssh().
"""
return self._wrap_connect(self._on_become_error, {
'method_name': 'sudo',
'username': self._play_context.become_user,
'password': self._play_context.become_pass,
'python_path': python_path or self.python_path,
'sudo_path': self.sudo_path,
'connect_timeout': self._play_context.timeout,
'via': via,
'sudo_args': [
term
for s in (
self._play_context.sudo_flags,
self._play_context.become_flags
)
for term in shlex.split(s or '')
],
})
def _connect(self):
"""
Establish a connection to the master process's UNIX listener socket,
constructing a mitogen.master.Router to communicate with the master,
and a mitogen.master.Context to represent it.
Depending on the original transport we should emulate, trigger one of
the _connect_*() service calls defined above to cause the master
process to establish the real connection on our behalf, or return a
reference to the existing one.
"""
if self.connected:
return
if not self.broker:
self.broker = mitogen.master.Broker()
self.router, self.parent = mitogen.unix.connect(
path=ansible_mitogen.process.MuxProcess.unix_listener_path,
broker=self.broker,
)
if self.original_transport == 'local':
if self._play_context.become:
self.context, self._homedir = self._connect_sudo(
python_path=sys.executable
)
else:
self.context, self._homedir = self._connect_local()
return
if self.original_transport == 'docker':
self.host, self._homedir = self._connect_docker()
elif self.original_transport == 'ssh':
self.host, self._homedir = self._connect_ssh()
if self._play_context.become:
self.context, self._homedir = self._connect_sudo(via=self.host)
else:
self.context = self.host
def get_context_name(self):
"""
Return the name of the target context we issue commands against, i.e. a
unique string useful as a key for related data, such as a list of
modules uploaded to the target.
"""
return self.context.name
def close(self, new_task=False):
"""
Arrange for the mitogen.master.Router running in the worker to
gracefully shut down, and wait for shutdown to complete. Safe to call
multiple times.
"""
for context in set([self.host, self.context]):
if context:
mitogen.service.call(
context=self.parent,
handle=ContextService.handle,
method='put',
kwargs={
'context': context
}
)
self.host = None
self.context = None
if self.broker and not new_task:
self.broker.shutdown()
self.broker.join()
self.broker = None
self.router = None
def call_async(self, func, *args, **kwargs):
"""
Start a function call to the target.
:returns:
mitogen.core.Receiver that receives the function call result.
"""
self._connect()
return self.context.call_async(func, *args, **kwargs)
def call(self, func, *args, **kwargs):
"""
Start and wait for completion of a function call in the target.
:raises mitogen.core.CallError:
The function call failed.
:returns:
Function return value.
"""
t0 = time.time()
try:
return self.call_async(func, *args, **kwargs).get().unpickle()
finally:
LOG.debug('Call %s%r took %d ms', func.func_name, args,
1000 * (time.time() - t0))
def exec_command(self, cmd, in_data='', sudoable=True, mitogen_chdir=None):
"""
Implement exec_command() by calling the corresponding
ansible_mitogen.target function in the target.
:param str cmd:
Shell command to execute.
:param bytes in_data:
Data to supply on ``stdin`` of the process.
:returns:
(return code, stdout bytes, stderr bytes)
"""
emulate_tty = (not in_data and sudoable)
rc, stdout, stderr = self.call(
ansible_mitogen.target.exec_command,
cmd=mitogen.utils.cast(cmd),
in_data=mitogen.utils.cast(in_data),
chdir=mitogen_chdir,
emulate_tty=emulate_tty,
)
stderr += 'Shared connection to %s closed.%s' % (
self._play_context.remote_addr,
('\r\n' if emulate_tty else '\n'),
)
return rc, stdout, stderr
def fetch_file(self, in_path, out_path):
"""
Implement fetch_file() by calling the corresponding
ansible_mitogen.target function in the target.
:param str in_path:
Remote filesystem path to read.
:param str out_path:
Local filesystem path to write.
"""
output = self.call(ansible_mitogen.target.read_path,
mitogen.utils.cast(in_path))
ansible_mitogen.target.write_path(out_path, output)
def put_data(self, out_path, data):
"""
Implement put_file() by caling the corresponding
ansible_mitogen.target function in the target.
:param str out_path:
Remote filesystem path to write.
:param byte data:
File contents to put.
"""
self.call(ansible_mitogen.target.write_path,
mitogen.utils.cast(out_path),
mitogen.utils.cast(data))
def put_file(self, in_path, out_path):
"""
Implement put_file() by caling the corresponding
ansible_mitogen.target function in the target.
:param str in_path:
Local filesystem path to read.
:param str out_path:
Remote filesystem path to write.
"""
self.put_data(out_path, ansible_mitogen.target.read_path(in_path))