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connection_plugins/packer.py for Ansible 2.9.0 and Packer 1.4.5
# Copyright (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
# Copyright 2015 Abhijit Menon-Sen <ams@2ndQuadrant.com>
# Copyright 2017 Toshio Kuratomi <tkuratomi@ansible.com>
# Copyright (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 = '''
connection: ssh
short_description: connect via ssh client binary
description:
- This connection plugin allows ansible to communicate to the target machines via normal ssh command line.
- Ansible does not expose a channel to allow communication between the user and the ssh process to accept
a password manually to decrypt an ssh key when using this connection plugin (which is the default). The
use of ``ssh-agent`` is highly recommended.
author: ansible (@core)
version_added: historical
options:
host:
description: Hostname/ip to connect to.
default: inventory_hostname
vars:
- name: ansible_host
- name: ansible_ssh_host
host_key_checking:
description: Determines if ssh should check host keys
type: boolean
ini:
- section: defaults
key: 'host_key_checking'
- section: ssh_connection
key: 'host_key_checking'
version_added: '2.5'
env:
- name: ANSIBLE_HOST_KEY_CHECKING
- name: ANSIBLE_SSH_HOST_KEY_CHECKING
version_added: '2.5'
vars:
- name: ansible_host_key_checking
version_added: '2.5'
- name: ansible_ssh_host_key_checking
version_added: '2.5'
password:
description: Authentication password for the C(remote_user). Can be supplied as CLI option.
vars:
- name: ansible_password
- name: ansible_ssh_pass
ssh_args:
description: Arguments to pass to all ssh cli tools
default: '-C -o ControlMaster=auto -o ControlPersist=60s'
ini:
- section: 'ssh_connection'
key: 'ssh_args'
env:
- name: ANSIBLE_SSH_ARGS
vars:
- name: ansible_ssh_args
version_added: '2.7'
ssh_common_args:
description: Common extra args for all ssh CLI tools
ini:
- section: 'ssh_connection'
key: 'ssh_common_args'
version_added: '2.7'
env:
- name: ANSIBLE_SSH_COMMON_ARGS
version_added: '2.7'
vars:
- name: ansible_ssh_common_args
ssh_executable:
default: ssh
description:
- This defines the location of the ssh binary. It defaults to ``ssh`` which will use the first ssh binary available in $PATH.
- This option is usually not required, it might be useful when access to system ssh is restricted,
or when using ssh wrappers to connect to remote hosts.
env: [{name: ANSIBLE_SSH_EXECUTABLE}]
ini:
- {key: ssh_executable, section: ssh_connection}
#const: ANSIBLE_SSH_EXECUTABLE
version_added: "2.2"
vars:
- name: ansible_ssh_executable
version_added: '2.7'
sftp_executable:
default: sftp
description:
- This defines the location of the sftp binary. It defaults to ``sftp`` which will use the first binary available in $PATH.
env: [{name: ANSIBLE_SFTP_EXECUTABLE}]
ini:
- {key: sftp_executable, section: ssh_connection}
version_added: "2.6"
vars:
- name: ansible_sftp_executable
version_added: '2.7'
scp_executable:
default: scp
description:
- This defines the location of the scp binary. It defaults to `scp` which will use the first binary available in $PATH.
env: [{name: ANSIBLE_SCP_EXECUTABLE}]
ini:
- {key: scp_executable, section: ssh_connection}
version_added: "2.6"
vars:
- name: ansible_scp_executable
version_added: '2.7'
scp_extra_args:
description: Extra exclusive to the ``scp`` CLI
vars:
- name: ansible_scp_extra_args
env:
- name: ANSIBLE_SCP_EXTRA_ARGS
version_added: '2.7'
ini:
- key: scp_extra_args
section: ssh_connection
version_added: '2.7'
sftp_extra_args:
description: Extra exclusive to the ``sftp`` CLI
vars:
- name: ansible_sftp_extra_args
env:
- name: ANSIBLE_SFTP_EXTRA_ARGS
version_added: '2.7'
ini:
- key: sftp_extra_args
section: ssh_connection
version_added: '2.7'
ssh_extra_args:
description: Extra exclusive to the 'ssh' CLI
vars:
- name: ansible_ssh_extra_args
env:
- name: ANSIBLE_SSH_EXTRA_ARGS
version_added: '2.7'
ini:
- key: ssh_extra_args
section: ssh_connection
version_added: '2.7'
retries:
# constant: ANSIBLE_SSH_RETRIES
description: Number of attempts to connect.
default: 3
type: integer
env:
- name: ANSIBLE_SSH_RETRIES
ini:
- section: connection
key: retries
- section: ssh_connection
key: retries
vars:
- name: ansible_ssh_retries
version_added: '2.7'
port:
description: Remote port to connect to.
type: int
default: 22
ini:
- section: defaults
key: remote_port
env:
- name: ANSIBLE_REMOTE_PORT
vars:
- name: ansible_port
- name: ansible_ssh_port
remote_user:
description:
- User name with which to login to the remote server, normally set by the remote_user keyword.
- If no user is supplied, Ansible will let the ssh client binary choose the user as it normally
ini:
- section: defaults
key: remote_user
env:
- name: ANSIBLE_REMOTE_USER
vars:
- name: ansible_user
- name: ansible_ssh_user
pipelining:
default: ANSIBLE_PIPELINING
description:
- Pipelining reduces the number of SSH operations required to execute a module on the remote server,
by executing many Ansible modules without actual file transfer.
- This can result in a very significant performance improvement when enabled.
- However this conflicts with privilege escalation (become).
For example, when using sudo operations you must first disable 'requiretty' in the sudoers file for the target hosts,
which is why this feature is disabled by default.
env:
- name: ANSIBLE_PIPELINING
#- name: ANSIBLE_SSH_PIPELINING
ini:
- section: defaults
key: pipelining
#- section: ssh_connection
# key: pipelining
type: boolean
vars:
- name: ansible_pipelining
- name: ansible_ssh_pipelining
private_key_file:
description:
- Path to private key file to use for authentication
ini:
- section: defaults
key: private_key_file
env:
- name: ANSIBLE_PRIVATE_KEY_FILE
vars:
- name: ansible_private_key_file
- name: ansible_ssh_private_key_file
control_path:
description:
- This is the location to save ssh's ControlPath sockets, it uses ssh's variable substitution.
- Since 2.3, if null, ansible will generate a unique hash. Use `%(directory)s` to indicate where to use the control dir path setting.
env:
- name: ANSIBLE_SSH_CONTROL_PATH
ini:
- key: control_path
section: ssh_connection
vars:
- name: ansible_control_path
version_added: '2.7'
control_path_dir:
default: ~/.ansible/cp
description:
- This sets the directory to use for ssh control path if the control path setting is null.
- Also, provides the `%(directory)s` variable for the control path setting.
env:
- name: ANSIBLE_SSH_CONTROL_PATH_DIR
ini:
- section: ssh_connection
key: control_path_dir
vars:
- name: ansible_control_path_dir
version_added: '2.7'
sftp_batch_mode:
default: 'yes'
description: 'TODO: write it'
env: [{name: ANSIBLE_SFTP_BATCH_MODE}]
ini:
- {key: sftp_batch_mode, section: ssh_connection}
type: bool
vars:
- name: ansible_sftp_batch_mode
version_added: '2.7'
scp_if_ssh:
default: smart
description:
- "Prefered method to use when transfering files over ssh"
- When set to smart, Ansible will try them until one succeeds or they all fail
- If set to True, it will force 'scp', if False it will use 'sftp'
env: [{name: ANSIBLE_SCP_IF_SSH}]
ini:
- {key: scp_if_ssh, section: ssh_connection}
vars:
- name: ansible_scp_if_ssh
version_added: '2.7'
use_tty:
version_added: '2.5'
default: 'yes'
description: add -tt to ssh commands to force tty allocation
env: [{name: ANSIBLE_SSH_USETTY}]
ini:
- {key: usetty, section: ssh_connection}
type: bool
vars:
- name: ansible_ssh_use_tty
version_added: '2.7'
'''
import errno
import fcntl
import hashlib
import os
import pty
import subprocess
import time
from functools import wraps
from ansible import constants as C
from ansible.errors import (
AnsibleAuthenticationFailure,
AnsibleConnectionFailure,
AnsibleError,
AnsibleFileNotFound,
)
from ansible.errors import AnsibleOptionsError
from ansible.compat import selectors
from ansible.module_utils.six import PY3, text_type, binary_type
from ansible.module_utils.six.moves import shlex_quote
from ansible.module_utils._text import to_bytes, to_native, to_text
from ansible.module_utils.parsing.convert_bool import BOOLEANS, boolean
from ansible.plugins.connection import ConnectionBase, BUFSIZE
from ansible.utils.path import unfrackpath, makedirs_safe
try:
from __main__ import display
except ImportError:
from ansible.utils.display import Display
display = Display()
b_NOT_SSH_ERRORS = (b'Traceback (most recent call last):', # Python-2.6 when there's an exception
# while invoking a script via -m
b'PHP Parse error:', # Php always returns error 255
)
SSHPASS_AVAILABLE = None
class AnsibleControlPersistBrokenPipeError(AnsibleError):
''' ControlPersist broken pipe '''
pass
def _handle_error(remaining_retries, command, return_tuple, no_log, host, display=display):
# sshpass errors
if command == b'sshpass':
# Error 5 is invalid/incorrect password. Raise an exception to prevent retries from locking the account.
if return_tuple[0] == 5:
msg = 'Invalid/incorrect username/password. Skipping remaining {0} retries to prevent account lockout:'.format(remaining_retries)
if remaining_retries <= 0:
msg = 'Invalid/incorrect password:'
if no_log:
msg = '{0} <error censored due to no log>'.format(msg)
else:
msg = '{0} {1}'.format(msg, to_native(return_tuple[2].rstrip()))
raise AnsibleAuthenticationFailure(msg)
# sshpass returns codes are 1-6. We handle 5 previously, so this catches other scenarios.
# No exception is raised, so the connection is retried.
elif return_tuple[0] in [1, 2, 3, 4, 6]:
msg = 'sshpass error:'
if no_log:
msg = '{0} <error censored due to no log>'.format(msg)
else:
msg = '{0} {1}'.format(msg, to_native(return_tuple[2].rstrip()))
if return_tuple[0] == 255:
SSH_ERROR = True
for signature in b_NOT_SSH_ERRORS:
if signature in return_tuple[1]:
SSH_ERROR = False
break
if SSH_ERROR:
msg = "Failed to connect to the host via ssh:"
if no_log:
msg = '{0} <error censored due to no log>'.format(msg)
else:
msg = '{0} {1}'.format(msg, to_native(return_tuple[2]).rstrip())
raise AnsibleConnectionFailure(msg)
# For other errors, no execption is raised so the connection is retried and we only log the messages
if 1 <= return_tuple[0] <= 254:
msg = "Failed to connect to the host via ssh:"
if no_log:
msg = '{0} <error censored due to no log>'.format(msg)
else:
msg = '{0} {1}'.format(msg, to_native(return_tuple[2]).rstrip())
display.vvv(msg, host=host)
def _ssh_retry(func):
"""
Decorator to retry ssh/scp/sftp in the case of a connection failure
Will retry if:
* an exception is caught
* ssh returns 255
Will not retry if
* sshpass returns 5 (invalid password, to prevent account lockouts)
* remaining_tries is < 2
* retries limit reached
"""
@wraps(func)
def wrapped(self, *args, **kwargs):
remaining_tries = int(C.ANSIBLE_SSH_RETRIES) + 1
cmd_summary = "%s..." % args[0]
for attempt in range(remaining_tries):
cmd = args[0]
if attempt != 0 and self._play_context.password and isinstance(cmd, list):
# If this is a retry, the fd/pipe for sshpass is closed, and we need a new one
self.sshpass_pipe = os.pipe()
cmd[1] = b'-d' + to_bytes(self.sshpass_pipe[0], nonstring='simplerepr', errors='surrogate_or_strict')
try:
try:
return_tuple = func(self, *args, **kwargs)
if self._play_context.no_log:
display.vvv('rc=%s, stdout and stderr censored due to no log' % return_tuple[0], host=self.host)
else:
display.vvv(return_tuple, host=self.host)
# 0 = success
# 1-254 = remote command return code
# 255 could be a failure from the ssh command itself
except (AnsibleControlPersistBrokenPipeError):
# Retry one more time because of the ControlPersist broken pipe (see #16731)
cmd = args[0]
if self._play_context.password and isinstance(cmd, list):
# This is a retry, so the fd/pipe for sshpass is closed, and we need a new one
self.sshpass_pipe = os.pipe()
cmd[1] = b'-d' + to_bytes(self.sshpass_pipe[0], nonstring='simplerepr', errors='surrogate_or_strict')
display.vvv(u"RETRYING BECAUSE OF CONTROLPERSIST BROKEN PIPE")
return_tuple = func(self, *args, **kwargs)
remaining_retries = remaining_tries - attempt - 1
_handle_error(remaining_retries, cmd[0], return_tuple, self._play_context.no_log, self.host)
break
# 5 = Invalid/incorrect password from sshpass
except AnsibleAuthenticationFailure as e:
# Raising this exception, which is subclassed from AnsibleConnectionFailure, prevents further retries
raise
except (AnsibleConnectionFailure, Exception) as e:
if attempt == remaining_tries - 1:
raise
else:
pause = 2 ** attempt - 1
if pause > 30:
pause = 30
if isinstance(e, AnsibleConnectionFailure):
msg = "ssh_retry: attempt: %d, ssh return code is 255. cmd (%s), pausing for %d seconds" % (attempt + 1, cmd_summary, pause)
else:
msg = "ssh_retry: attempt: %d, caught exception(%s) from cmd (%s), pausing for %d seconds" % (attempt + 1, e, cmd_summary, pause)
display.vv(msg, host=self.host)
time.sleep(pause)
continue
return return_tuple
return wrapped
class Connection(ConnectionBase):
''' ssh based connections '''
transport = 'packer'
has_pipelining = True
become_methods = []
allow_executable = False
module_implementation_preferences = ('.ps1', '')
def __init__(self, *args, **kwargs):
super(Connection, self).__init__(*args, **kwargs)
self.host = self._play_context.remote_addr
self.port = self._play_context.port
self.user = self._play_context.remote_user
self.control_path = C.ANSIBLE_SSH_CONTROL_PATH
self.control_path_dir = C.ANSIBLE_SSH_CONTROL_PATH_DIR
# The connection is created by running ssh/scp/sftp from the exec_command,
# put_file, and fetch_file methods, so we don't need to do any connection
# management here.
def _connect(self):
return self
@staticmethod
def _create_control_path(host, port, user, connection=None, pid=None):
'''Make a hash for the controlpath based on con attributes'''
pstring = '%s-%s-%s' % (host, port, user)
if connection:
pstring += '-%s' % connection
if pid:
pstring += '-%s' % to_text(pid)
m = hashlib.sha1()
m.update(to_bytes(pstring))
digest = m.hexdigest()
cpath = '%(directory)s/' + digest[:10]
return cpath
@staticmethod
def _sshpass_available():
global SSHPASS_AVAILABLE
# We test once if sshpass is available, and remember the result. It
# would be nice to use distutils.spawn.find_executable for this, but
# distutils isn't always available; shutils.which() is Python3-only.
if SSHPASS_AVAILABLE is None:
try:
p = subprocess.Popen(["sshpass"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
p.communicate()
SSHPASS_AVAILABLE = True
except OSError:
SSHPASS_AVAILABLE = False
return SSHPASS_AVAILABLE
@staticmethod
def _persistence_controls(b_command):
'''
Takes a command array and scans it for ControlPersist and ControlPath
settings and returns two booleans indicating whether either was found.
This could be smarter, e.g. returning false if ControlPersist is 'no',
but for now we do it simple way.
'''
controlpersist = False
controlpath = False
for b_arg in (a.lower() for a in b_command):
if b'controlpersist' in b_arg:
controlpersist = True
elif b'controlpath' in b_arg:
controlpath = True
return controlpersist, controlpath
def _add_args(self, b_command, b_args, explanation):
"""
Adds arguments to the ssh command and displays a caller-supplied explanation of why.
:arg b_command: A list containing the command to add the new arguments to.
This list will be modified by this method.
:arg b_args: An iterable of new arguments to add. This iterable is used
more than once so it must be persistent (ie: a list is okay but a
StringIO would not)
:arg explanation: A text string containing explaining why the arguments
were added. It will be displayed with a high enough verbosity.
.. note:: This function does its work via side-effect. The b_command list has the new arguments appended.
"""
display.vvvvv(u'SSH: %s: (%s)' % (explanation, ')('.join(to_text(a) for a in b_args)), host=self._play_context.remote_addr)
b_command += b_args
def _build_command(self, binary, *other_args):
'''
Takes a binary (ssh, scp, sftp) and optional extra arguments and returns
a command line as an array that can be passed to subprocess.Popen.
'''
b_command = []
#
# First, the command to invoke
#
# If we want to use password authentication, we have to set up a pipe to
# write the password to sshpass.
if self._play_context.password:
if not self._sshpass_available():
raise AnsibleError("to use the 'ssh' connection type with passwords, you must install the sshpass program")
self.sshpass_pipe = os.pipe()
b_command += [b'sshpass', b'-d' + to_bytes(self.sshpass_pipe[0], nonstring='simplerepr', errors='surrogate_or_strict')]
if binary == 'ssh':
b_command += [to_bytes(self._play_context.ssh_executable, errors='surrogate_or_strict')]
else:
b_command += [to_bytes(binary, errors='surrogate_or_strict')]
#
# Next, additional arguments based on the configuration.
#
# sftp batch mode allows us to correctly catch failed transfers, but can
# be disabled if the client side doesn't support the option. However,
# sftp batch mode does not prompt for passwords so it must be disabled
# if not using controlpersist and using sshpass
if binary == 'sftp' and C.DEFAULT_SFTP_BATCH_MODE:
if self._play_context.password:
b_args = [b'-o', b'BatchMode=no']
self._add_args(b_command, b_args, u'disable batch mode for sshpass')
b_command += [b'-b', b'-']
if self._play_context.verbosity > 3:
b_command.append(b'-vvv')
#
# Next, we add [ssh_connection]ssh_args from ansible.cfg.
#
if self._play_context.ssh_args:
b_args = [to_bytes(a, errors='surrogate_or_strict') for a in
self._split_ssh_args(self._play_context.ssh_args)]
self._add_args(b_command, b_args, u"ansible.cfg set ssh_args")
# Now we add various arguments controlled by configuration file settings
# (e.g. host_key_checking) or inventory variables (ansible_ssh_port) or
# a combination thereof.
if not C.HOST_KEY_CHECKING:
b_args = (b"-o", b"StrictHostKeyChecking=no")
self._add_args(b_command, b_args, u"ANSIBLE_HOST_KEY_CHECKING/host_key_checking disabled")
if self._play_context.port is not None:
b_args = (b"-o", b"Port=" + to_bytes(self._play_context.port, nonstring='simplerepr', errors='surrogate_or_strict'))
self._add_args(b_command, b_args, u"ANSIBLE_REMOTE_PORT/remote_port/ansible_port set")
key = self._play_context.private_key_file
if key:
b_args = (b"-o", b'IdentityFile="' + to_bytes(os.path.expanduser(key), errors='surrogate_or_strict') + b'"')
self._add_args(b_command, b_args, u"ANSIBLE_PRIVATE_KEY_FILE/private_key_file/ansible_ssh_private_key_file set")
if not self._play_context.password:
self._add_args(
b_command, (
b"-o", b"KbdInteractiveAuthentication=no",
b"-o", b"PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey",
b"-o", b"PasswordAuthentication=no"
),
u"ansible_password/ansible_ssh_pass not set"
)
user = self._play_context.remote_user
if user:
self._add_args(
b_command,
(b"-o", b"User=" + to_bytes(self._play_context.remote_user, errors='surrogate_or_strict')),
u"ANSIBLE_REMOTE_USER/remote_user/ansible_user/user/-u set"
)
self._add_args(
b_command,
(b"-o", b"ConnectTimeout=" + to_bytes(self._play_context.timeout, errors='surrogate_or_strict', nonstring='simplerepr')),
u"ANSIBLE_TIMEOUT/timeout set"
)
# Add in any common or binary-specific arguments from the PlayContext
# (i.e. inventory or task settings or overrides on the command line).
for opt in (u'ssh_common_args', u'{0}_extra_args'.format(binary)):
attr = getattr(self._play_context, opt, None)
if attr is not None:
b_args = [to_bytes(a, errors='surrogate_or_strict') for a in self._split_ssh_args(attr)]
self._add_args(b_command, b_args, u"PlayContext set %s" % opt)
# Check if ControlPersist is enabled and add a ControlPath if one hasn't
# already been set.
controlpersist, controlpath = self._persistence_controls(b_command)
if controlpersist:
self._persistent = True
if not controlpath:
cpdir = unfrackpath(self.control_path_dir)
b_cpdir = to_bytes(cpdir, errors='surrogate_or_strict')
# The directory must exist and be writable.
makedirs_safe(b_cpdir, 0o700)
if not os.access(b_cpdir, os.W_OK):
raise AnsibleError("Cannot write to ControlPath %s" % to_native(cpdir))
if not self.control_path:
self.control_path = self._create_control_path(
self.host,
self.port,
self.user
)
b_args = (b"-o", b"ControlPath=" + to_bytes(self.control_path % dict(directory=cpdir), errors='surrogate_or_strict'))
self._add_args(b_command, b_args, u"found only ControlPersist; added ControlPath")
# Finally, we add any caller-supplied extras.
if other_args:
b_command += [to_bytes(a) for a in other_args]
return b_command
def _send_initial_data(self, fh, in_data, ssh_process):
'''
Writes initial data to the stdin filehandle of the subprocess and closes
it. (The handle must be closed; otherwise, for example, "sftp -b -" will
just hang forever waiting for more commands.)
'''
display.debug('Sending initial data')
try:
fh.write(to_bytes(in_data))
fh.close()
except (OSError, IOError):
# The ssh connection may have already terminated at this point, with a more useful error
# Only raise AnsibleConnectionFailure if the ssh process is still alive
time.sleep(0.001)
ssh_process.poll()
if getattr(ssh_process, 'returncode', None) is None:
raise AnsibleConnectionFailure(
'SSH Error: data could not be sent to remote host "%s". Make sure this host can be reached '
'over ssh' % self.host
)
display.debug('Sent initial data (%d bytes)' % len(in_data))
# Used by _run() to kill processes on failures
@staticmethod
def _terminate_process(p):
""" Terminate a process, ignoring errors """
try:
p.terminate()
except (OSError, IOError):
pass
# This is separate from _run() because we need to do the same thing for stdout
# and stderr.
def _examine_output(self, source, state, b_chunk, sudoable):
'''
Takes a string, extracts complete lines from it, tests to see if they
are a prompt, error message, etc., and sets appropriate flags in self.
Prompt and success lines are removed.
Returns the processed (i.e. possibly-edited) output and the unprocessed
remainder (to be processed with the next chunk) as strings.
'''
output = []
for b_line in b_chunk.splitlines(True):
display_line = to_text(b_line).rstrip('\r\n')
suppress_output = False
# display.debug("Examining line (source=%s, state=%s): '%s'" % (source, state, display_line))
if self._play_context.prompt and self.check_password_prompt(b_line):
display.debug("become_prompt: (source=%s, state=%s): '%s'" % (source, state, display_line))
self._flags['become_prompt'] = True
suppress_output = True
elif self._play_context.success_key and self.check_become_success(b_line):
display.debug("become_success: (source=%s, state=%s): '%s'" % (source, state, display_line))
self._flags['become_success'] = True
suppress_output = True
elif sudoable and self.check_incorrect_password(b_line):
display.debug("become_error: (source=%s, state=%s): '%s'" % (source, state, display_line))
self._flags['become_error'] = True
elif sudoable and self.check_missing_password(b_line):
display.debug("become_nopasswd_error: (source=%s, state=%s): '%s'" % (source, state, display_line))
self._flags['become_nopasswd_error'] = True
if not suppress_output:
output.append(b_line)
# The chunk we read was most likely a series of complete lines, but just
# in case the last line was incomplete (and not a prompt, which we would
# have removed from the output), we retain it to be processed with the
# next chunk.
remainder = b''
if output and not output[-1].endswith(b'\n'):
remainder = output[-1]
output = output[:-1]
return b''.join(output), remainder
def _bare_run(self, cmd, in_data, sudoable=True, checkrc=True):
'''
Starts the command and communicates with it until it ends.
'''
display_cmd = list(map(shlex_quote, map(to_text, cmd)))
display.vvv(u'SSH: EXEC {0}'.format(u' '.join(display_cmd)), host=self.host)
# Start the given command. If we don't need to pipeline data, we can try
# to use a pseudo-tty (ssh will have been invoked with -tt). If we are
# pipelining data, or can't create a pty, we fall back to using plain
# old pipes.
p = None
if isinstance(cmd, (text_type, binary_type)):
cmd = to_bytes(cmd)
else:
cmd = list(map(to_bytes, cmd))
if not in_data:
try:
# Make sure stdin is a proper pty to avoid tcgetattr errors
master, slave = pty.openpty()
if PY3 and self._play_context.password:
# pylint: disable=unexpected-keyword-arg
p = subprocess.Popen(cmd, stdin=slave, stdout=subprocess.PIPE, stderr=subprocess.PIPE, pass_fds=self.sshpass_pipe)
else:
p = subprocess.Popen(cmd, stdin=slave, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
stdin = os.fdopen(master, 'wb', 0)
os.close(slave)
except (OSError, IOError):
p = None
if not p:
if PY3 and self._play_context.password:
# pylint: disable=unexpected-keyword-arg
p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, pass_fds=self.sshpass_pipe)
else:
p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
stdin = p.stdin
# If we are using SSH password authentication, write the password into
# the pipe we opened in _build_command.
if self._play_context.password:
os.close(self.sshpass_pipe[0])
try:
os.write(self.sshpass_pipe[1], to_bytes(self._play_context.password) + b'\n')
except OSError as e:
# Ignore broken pipe errors if the sshpass process has exited.
if e.errno != errno.EPIPE or p.poll() is None:
raise
os.close(self.sshpass_pipe[1])
#
# SSH state machine
#
# Now we read and accumulate output from the running process until it
# exits. Depending on the circumstances, we may also need to write an
# escalation password and/or pipelined input to the process.
states = [
'awaiting_prompt', 'awaiting_escalation', 'ready_to_send', 'awaiting_exit'
]
# Are we requesting privilege escalation? Right now, we may be invoked
# to execute sftp/scp with sudoable=True, but we can request escalation
# only when using ssh. Otherwise we can send initial data straightaway.
state = states.index('ready_to_send')
if to_bytes(self.get_option('ssh_executable')) in cmd and sudoable:
if self._play_context.prompt:
# We're requesting escalation with a password, so we have to
# wait for a password prompt.
state = states.index('awaiting_prompt')
display.debug(u'Initial state: %s: %s' % (states[state], self._play_context.prompt))
elif self._play_context.become and self._play_context.success_key:
# We're requesting escalation without a password, so we have to
# detect success/failure before sending any initial data.
state = states.index('awaiting_escalation')
display.debug(u'Initial state: %s: %s' % (states[state], self._play_context.success_key))
# We store accumulated stdout and stderr output from the process here,
# but strip any privilege escalation prompt/confirmation lines first.
# Output is accumulated into tmp_*, complete lines are extracted into
# an array, then checked and removed or copied to stdout or stderr. We
# set any flags based on examining the output in self._flags.
b_stdout = b_stderr = b''
b_tmp_stdout = b_tmp_stderr = b''
self._flags = dict(
become_prompt=False, become_success=False,
become_error=False, become_nopasswd_error=False
)
# select timeout should be longer than the connect timeout, otherwise
# they will race each other when we can't connect, and the connect
# timeout usually fails
timeout = 2 + self._play_context.timeout
for fd in (p.stdout, p.stderr):
fcntl.fcntl(fd, fcntl.F_SETFL, fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK)
# TODO: bcoca would like to use SelectSelector() when open
# filehandles is low, then switch to more efficient ones when higher.
# select is faster when filehandles is low.
selector = selectors.DefaultSelector()
selector.register(p.stdout, selectors.EVENT_READ)
selector.register(p.stderr, selectors.EVENT_READ)
# If we can send initial data without waiting for anything, we do so
# before we start polling
if states[state] == 'ready_to_send' and in_data:
self._send_initial_data(stdin, in_data, p)
state += 1
try:
while True:
poll = p.poll()
events = selector.select(timeout)
# We pay attention to timeouts only while negotiating a prompt.
if not events:
# We timed out
if state <= states.index('awaiting_escalation'):
# If the process has already exited, then it's not really a
# timeout; we'll let the normal error handling deal with it.
if poll is not None:
break
self._terminate_process(p)
raise AnsibleError('Timeout (%ds) waiting for privilege escalation prompt: %s' % (timeout, to_native(b_stdout)))
# Read whatever output is available on stdout and stderr, and stop
# listening to the pipe if it's been closed.
for key, event in events:
if key.fileobj == p.stdout:
b_chunk = p.stdout.read()
if b_chunk == b'':
# stdout has been closed, stop watching it
selector.unregister(p.stdout)
# When ssh has ControlMaster (+ControlPath/Persist) enabled, the
# first connection goes into the background and we never see EOF
# on stderr. If we see EOF on stdout, lower the select timeout
# to reduce the time wasted selecting on stderr if we observe
# that the process has not yet existed after this EOF. Otherwise
# we may spend a long timeout period waiting for an EOF that is
# not going to arrive until the persisted connection closes.
timeout = 1
b_tmp_stdout += b_chunk
display.debug("stdout chunk (state=%s):\n>>>%s<<<\n" % (state, to_text(b_chunk)))
elif key.fileobj == p.stderr:
b_chunk = p.stderr.read()
if b_chunk == b'':
# stderr has been closed, stop watching it
selector.unregister(p.stderr)
b_tmp_stderr += b_chunk
display.debug("stderr chunk (state=%s):\n>>>%s<<<\n" % (state, to_text(b_chunk)))
# We examine the output line-by-line until we have negotiated any
# privilege escalation prompt and subsequent success/error message.
# Afterwards, we can accumulate output without looking at it.
if state < states.index('ready_to_send'):
if b_tmp_stdout:
b_output, b_unprocessed = self._examine_output('stdout', states[state], b_tmp_stdout, sudoable)
b_stdout += b_output
b_tmp_stdout = b_unprocessed
if b_tmp_stderr:
b_output, b_unprocessed = self._examine_output('stderr', states[state], b_tmp_stderr, sudoable)
b_stderr += b_output
b_tmp_stderr = b_unprocessed
else:
b_stdout += b_tmp_stdout
b_stderr += b_tmp_stderr
b_tmp_stdout = b_tmp_stderr = b''
# If we see a privilege escalation prompt, we send the password.
# (If we're expecting a prompt but the escalation succeeds, we
# didn't need the password and can carry on regardless.)
if states[state] == 'awaiting_prompt':
if self._flags['become_prompt']:
display.debug('Sending become_pass in response to prompt')
stdin.write(to_bytes(self._play_context.become_pass) + b'\n')
# On python3 stdin is a BufferedWriter, and we don't have a guarantee
# that the write will happen without a flush
stdin.flush()
self._flags['become_prompt'] = False
state += 1
elif self._flags['become_success']:
state += 1
# We've requested escalation (with or without a password), now we
# wait for an error message or a successful escalation.
if states[state] == 'awaiting_escalation':
if self._flags['become_success']:
display.vvv('Escalation succeeded')
self._flags['become_success'] = False
state += 1
elif self._flags['become_error']:
display.vvv('Escalation failed')
self._terminate_process(p)
self._flags['become_error'] = False
raise AnsibleError('Incorrect %s password' % self._play_context.become_method)
elif self._flags['become_nopasswd_error']:
display.vvv('Escalation requires password')
self._terminate_process(p)
self._flags['become_nopasswd_error'] = False
raise AnsibleError('Missing %s password' % self._play_context.become_method)
elif self._flags['become_prompt']:
# This shouldn't happen, because we should see the "Sorry,
# try again" message first.
display.vvv('Escalation prompt repeated')
self._terminate_process(p)
self._flags['become_prompt'] = False
raise AnsibleError('Incorrect %s password' % self._play_context.become_method)
# Once we're sure that the privilege escalation prompt, if any, has
# been dealt with, we can send any initial data and start waiting
# for output.
if states[state] == 'ready_to_send':
if in_data:
self._send_initial_data(stdin, in_data, p)
state += 1
# Now we're awaiting_exit: has the child process exited? If it has,
# and we've read all available output from it, we're done.
if poll is not None:
if not selector.get_map() or not events:
break
# We should not see further writes to the stdout/stderr file
# descriptors after the process has closed, set the select
# timeout to gather any last writes we may have missed.
timeout = 0
continue
# If the process has not yet exited, but we've already read EOF from
# its stdout and stderr (and thus no longer watching any file
# descriptors), we can just wait for it to exit.
elif not selector.get_map():
p.wait()
break
# Otherwise there may still be outstanding data to read.
finally:
selector.close()
# close stdin after process is terminated and stdout/stderr are read
# completely (see also issue #848)
stdin.close()
if C.HOST_KEY_CHECKING:
if cmd[0] == b"sshpass" and p.returncode == 6:
raise AnsibleError('Using a SSH password instead of a key is not possible because Host Key checking is enabled and sshpass does not support '
'this. Please add this host\'s fingerprint to your known_hosts file to manage this host.')
controlpersisterror = b'Bad configuration option: ControlPersist' in b_stderr or b'unknown configuration option: ControlPersist' in b_stderr
if p.returncode != 0 and controlpersisterror:
raise AnsibleError('using -c ssh on certain older ssh versions may not support ControlPersist, set ANSIBLE_SSH_ARGS="" '
'(or ssh_args in [ssh_connection] section of the config file) before running again')
# If we find a broken pipe because of ControlPersist timeout expiring (see #16731),
# we raise a special exception so that we can retry a connection.
controlpersist_broken_pipe = b'mux_client_hello_exchange: write packet: Broken pipe' in b_stderr
if p.returncode == 255 and controlpersist_broken_pipe:
raise AnsibleControlPersistBrokenPipeError('SSH Error: data could not be sent because of ControlPersist broken pipe.')
if p.returncode == 255 and in_data and checkrc:
raise AnsibleConnectionFailure('SSH Error: data could not be sent to remote host "%s". Make sure this host can be reached over ssh' % self.host)
return (p.returncode, b_stdout, b_stderr)
@_ssh_retry
def _run(self, cmd, in_data, sudoable=True, checkrc=True):
"""Wrapper around _bare_run that retries the connection
"""
return self._bare_run(cmd, in_data, sudoable=sudoable, checkrc=checkrc)
@_ssh_retry
def _file_transport_command(self, in_path, out_path, sftp_action):
# scp and sftp require square brackets for IPv6 addresses, but
# accept them for hostnames and IPv4 addresses too.
host = '[%s]' % self.host
# Transfer methods to try
methods = []
# Use the transfer_method option if set, otherwise use scp_if_ssh
ssh_transfer_method = self._play_context.ssh_transfer_method
if ssh_transfer_method is not None:
if not (ssh_transfer_method in ('smart', 'sftp', 'scp', 'piped')):
raise AnsibleOptionsError('transfer_method needs to be one of [smart|sftp|scp|piped]')
if ssh_transfer_method == 'smart':
methods = ['sftp', 'scp', 'piped']
else:
methods = [ssh_transfer_method]
else:
# since this can be a non-bool now, we need to handle it correctly
scp_if_ssh = C.DEFAULT_SCP_IF_SSH
if not isinstance(scp_if_ssh, bool):
scp_if_ssh = scp_if_ssh.lower()
if scp_if_ssh in BOOLEANS:
scp_if_ssh = boolean(scp_if_ssh, strict=False)
elif scp_if_ssh != 'smart':
raise AnsibleOptionsError('scp_if_ssh needs to be one of [smart|True|False]')
if scp_if_ssh == 'smart':
methods = ['sftp', 'scp', 'piped']
elif scp_if_ssh is True:
methods = ['scp']
else:
methods = ['sftp']
for method in methods:
returncode = stdout = stderr = None
if method == 'sftp':
cmd = self._build_command(self.get_option('sftp_executable'), to_bytes(host))
in_data = u"{0} {1} {2}\n".format(sftp_action, shlex_quote(in_path), shlex_quote(out_path))
in_data = to_bytes(in_data, nonstring='passthru')
(returncode, stdout, stderr) = self._bare_run(cmd, in_data, checkrc=False)
elif method == 'scp':
scp = self.get_option('scp_executable')
if sftp_action == 'get':
cmd = self._build_command(scp, u'{0}:{1}'.format(host, shlex_quote(in_path)), out_path)
else:
cmd = self._build_command(scp, in_path, u'{0}:{1}'.format(host, shlex_quote(out_path)))
in_data = None
(returncode, stdout, stderr) = self._bare_run(cmd, in_data, checkrc=False)
elif method == 'piped':
if sftp_action == 'get':
# we pass sudoable=False to disable pty allocation, which
# would end up mixing stdout/stderr and screwing with newlines
(returncode, stdout, stderr) = self.exec_command('dd if=%s bs=%s' % (in_path, BUFSIZE), sudoable=False)
with open(to_bytes(out_path, errors='surrogate_or_strict'), 'wb+') as out_file:
out_file.write(stdout)
else:
with open(to_bytes(in_path, errors='surrogate_or_strict'), 'rb') as f:
in_data = to_bytes(f.read(), nonstring='passthru')
if not in_data:
count = ' count=0'
else:
count = ''
(returncode, stdout, stderr) = self.exec_command('dd of=%s bs=%s%s' % (out_path, BUFSIZE, count), in_data=in_data, sudoable=False)
# Check the return code and rollover to next method if failed
if returncode == 0:
return (returncode, stdout, stderr)
else:
# If not in smart mode, the data will be printed by the raise below
if len(methods) > 1:
display.warning(msg='%s transfer mechanism failed on %s. Use ANSIBLE_DEBUG=1 to see detailed information' % (method, host))
display.debug(msg='%s' % to_native(stdout))
display.debug(msg='%s' % to_native(stderr))
if returncode == 255:
raise AnsibleConnectionFailure("Failed to connect to the host via %s: %s" % (method, to_native(stderr)))
else:
raise AnsibleError("failed to transfer file to %s %s:\n%s\n%s" %
(to_native(in_path), to_native(out_path), to_native(stdout), to_native(stderr)))
#
# Main public methods
#
def exec_command(self, cmd, in_data=None, sudoable=True):
''' run a command on the remote host '''
super(Connection, self).exec_command(cmd, in_data=in_data, sudoable=sudoable)
display.vvv(u"ESTABLISH SSH CONNECTION FOR USER: {0}".format(self._play_context.remote_user), host=self._play_context.remote_addr)
# we can only use tty when we are not pipelining the modules. piping
# data into /usr/bin/python inside a tty automatically invokes the
# python interactive-mode but the modules are not compatible with the
# interactive-mode ("unexpected indent" mainly because of empty lines)
ssh_executable = self._play_context.ssh_executable
# -tt can cause various issues in some environments so allow the user
# to disable it as a troubleshooting method.
use_tty = self.get_option('use_tty')
if not in_data and sudoable and use_tty:
args = (ssh_executable, '-tt', self.host, cmd)
else:
args = (ssh_executable, self.host, cmd)
cmd = self._build_command(*args)
(returncode, stdout, stderr) = self._run(cmd, in_data, sudoable=sudoable)
return (returncode, stdout, stderr)
def put_file(self, in_path, out_path):
''' transfer a file from local to remote '''
super(Connection, self).put_file(in_path, out_path)
display.vvv(u"PUT {0} TO {1}".format(in_path, out_path), host=self.host)
if not os.path.exists(to_bytes(in_path, errors='surrogate_or_strict')):
raise AnsibleFileNotFound("file or module does not exist: {0}".format(to_native(in_path)))
return self._file_transport_command(in_path, out_path, 'put')
def fetch_file(self, in_path, out_path):
''' fetch a file from remote to local '''
super(Connection, self).fetch_file(in_path, out_path)
display.vvv(u"FETCH {0} TO {1}".format(in_path, out_path), host=self.host)
return self._file_transport_command(in_path, out_path, 'get')
def reset(self):
# If we have a persistent ssh connection (ControlPersist), we can ask it to stop listening.
cmd = self._build_command(self._play_context.ssh_executable, '-O', 'stop', self.host)
controlpersist, controlpath = self._persistence_controls(cmd)
cp_arg = [a for a in cmd if a.startswith(b"ControlPath=")]
# only run the reset if the ControlPath already exists or if it isn't
# configured and ControlPersist is set
run_reset = False
if controlpersist and len(cp_arg) > 0:
cp_path = cp_arg[0].split(b"=", 1)[-1]
if os.path.exists(cp_path):
run_reset = True
elif controlpersist:
run_reset = True
if run_reset:
display.vvv(u'sending stop: %s' % cmd)
p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
stdout, stderr = p.communicate()
status_code = p.wait()
if status_code != 0:
display.warning("Failed to reset connection:%s" % stderr)
self.close()
def close(self):
self._connected = False
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