Re-order the methods in ssh.py so that methods needed for implementation are near and just above the relevant public methods.

Standard with the rest of the code base.
This commit is contained in:
Toshio Kuratomi 2015-09-28 10:34:02 -07:00
parent 37844a5c1b
commit d827325644

View file

@ -65,18 +65,60 @@ class Connection(ConnectionBase):
self._connected = True self._connected = True
return self return self
def close(self): @staticmethod
# If we have a persistent ssh connection (ControlPersist), we can ask it def _sshpass_available():
# to stop listening. Otherwise, there's nothing to do here. global SSHPASS_AVAILABLE
# TODO: reenable once winrm issues are fixed # We test once if sshpass is available, and remember the result. It
# temporarily disabled as we are forced to currently close connections after every task because of winrm # would be nice to use distutils.spawn.find_executable for this, but
# if self._connected and self._persistent: # distutils isn't always available; shutils.which() is Python3-only.
# cmd = self._build_command('ssh', '-O', 'stop', self.host)
# p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
# stdout, stderr = p.communicate()
self._connected = False 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(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 arg in command:
if 'controlpersist' in arg.lower():
controlpersist = True
elif 'controlpath' in arg.lower():
controlpath = True
return controlpersist, controlpath
@staticmethod
def _split_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.
"""
return [x.strip() for x in shlex.split(argstring) if x.strip()]
def _add_args(self, explanation, args):
"""
Adds the given args to self._command and displays a caller-supplied
explanation of why they were added.
"""
self._command += args
self._display.vvvvv('SSH: ' + explanation + ': (%s)' % ')('.join(args), host=self._play_context.remote_addr)
def _build_command(self, binary, *other_args): def _build_command(self, binary, *other_args):
''' '''
@ -124,42 +166,42 @@ class Connection(ConnectionBase):
if self.ssh_args: if self.ssh_args:
args = self._split_args(self.ssh_args) args = self._split_args(self.ssh_args)
self.add_args("inventory set ansible_ssh_args", args) self._add_args("inventory set ansible_ssh_args", args)
elif C.ANSIBLE_SSH_ARGS: elif C.ANSIBLE_SSH_ARGS:
args = self._split_args(C.ANSIBLE_SSH_ARGS) args = self._split_args(C.ANSIBLE_SSH_ARGS)
self.add_args("ansible.cfg set ssh_args", args) self._add_args("ansible.cfg set ssh_args", args)
else: else:
args = ( args = (
"-o", "ControlMaster=auto", "-o", "ControlMaster=auto",
"-o", "ControlPersist=60s" "-o", "ControlPersist=60s"
) )
self.add_args("default arguments", args) self._add_args("default arguments", args)
# Now we add various arguments controlled by configuration file settings # Now we add various arguments controlled by configuration file settings
# (e.g. host_key_checking) or inventory variables (ansible_ssh_port) or # (e.g. host_key_checking) or inventory variables (ansible_ssh_port) or
# a combination thereof. # a combination thereof.
if not C.HOST_KEY_CHECKING: if not C.HOST_KEY_CHECKING:
self.add_args( self._add_args(
"ANSIBLE_HOST_KEY_CHECKING/host_key_checking disabled", "ANSIBLE_HOST_KEY_CHECKING/host_key_checking disabled",
("-o", "StrictHostKeyChecking=no") ("-o", "StrictHostKeyChecking=no")
) )
if self._play_context.port is not None: if self._play_context.port is not None:
self.add_args( self._add_args(
"ANSIBLE_REMOTE_PORT/remote_port/ansible_ssh_port set", "ANSIBLE_REMOTE_PORT/remote_port/ansible_ssh_port set",
("-o", "Port={0}".format(self._play_context.port)) ("-o", "Port={0}".format(self._play_context.port))
) )
key = self._play_context.private_key_file key = self._play_context.private_key_file
if key: if key:
self.add_args( self._add_args(
"ANSIBLE_PRIVATE_KEY_FILE/private_key_file/ansible_ssh_private_key_file set", "ANSIBLE_PRIVATE_KEY_FILE/private_key_file/ansible_ssh_private_key_file set",
("-o", "IdentityFile=\"{0}\"".format(os.path.expanduser(key))) ("-o", "IdentityFile=\"{0}\"".format(os.path.expanduser(key)))
) )
if not self._play_context.password: if not self._play_context.password:
self.add_args( self._add_args(
"ansible_password/ansible_ssh_pass not set", ( "ansible_password/ansible_ssh_pass not set", (
"-o", "KbdInteractiveAuthentication=no", "-o", "KbdInteractiveAuthentication=no",
"-o", "PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey", "-o", "PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey",
@ -169,12 +211,12 @@ class Connection(ConnectionBase):
user = self._play_context.remote_user user = self._play_context.remote_user
if user and user != pwd.getpwuid(os.geteuid())[0]: if user and user != pwd.getpwuid(os.geteuid())[0]:
self.add_args( self._add_args(
"ANSIBLE_REMOTE_USER/remote_user/ansible_ssh_user/user/-u set", "ANSIBLE_REMOTE_USER/remote_user/ansible_ssh_user/user/-u set",
("-o", "User={0}".format(self._play_context.remote_user)) ("-o", "User={0}".format(self._play_context.remote_user))
) )
self.add_args( self._add_args(
"ANSIBLE_TIMEOUT/timeout set", "ANSIBLE_TIMEOUT/timeout set",
("-o", "ConnectTimeout={0}".format(self._play_context.timeout)) ("-o", "ConnectTimeout={0}".format(self._play_context.timeout))
) )
@ -185,10 +227,10 @@ class Connection(ConnectionBase):
if self._play_context.ssh_extra_args: if self._play_context.ssh_extra_args:
args = self._split_args(self._play_context.ssh_extra_args) args = self._split_args(self._play_context.ssh_extra_args)
self.add_args("command-line added --ssh-extra-args", args) self._add_args("command-line added --ssh-extra-args", args)
elif self.ssh_extra_args: elif self.ssh_extra_args:
args = self._split_args(self.ssh_extra_args) args = self._split_args(self.ssh_extra_args)
self.add_args("inventory added ansible_ssh_extra_args", args) self._add_args("inventory added ansible_ssh_extra_args", args)
# Check if ControlPersist is enabled (either by default, or using # Check if ControlPersist is enabled (either by default, or using
# ssh_args or ssh_extra_args) and add a ControlPath if one hasn't # ssh_args or ssh_extra_args) and add a ControlPath if one hasn't
@ -210,7 +252,7 @@ class Connection(ConnectionBase):
args = ("-o", "ControlPath={0}".format( args = ("-o", "ControlPath={0}".format(
C.ANSIBLE_SSH_CONTROL_PATH % dict(directory=cpdir)) C.ANSIBLE_SSH_CONTROL_PATH % dict(directory=cpdir))
) )
self.add_args("found only ControlPersist; added ControlPath", args) self._add_args("found only ControlPersist; added ControlPath", args)
## Finally, we add any caller-supplied extras. ## Finally, we add any caller-supplied extras.
@ -219,118 +261,78 @@ class Connection(ConnectionBase):
return self._command return self._command
def exec_command(self, *args, **kwargs): def _send_initial_data(self, fh, in_data):
""" '''
Wrapper around _exec_command to retry in the case of an ssh failure 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.)
'''
Will retry if: self._display.debug('Sending initial data')
* an exception is caught
* ssh returns 255
Will not retry if
* remaining_tries is <2
* retries limit reached
"""
remaining_tries = int(C.ANSIBLE_SSH_RETRIES) + 1
cmd_summary = "%s..." % args[0]
for attempt in xrange(remaining_tries):
try: try:
return_tuple = self._exec_command(*args, **kwargs) fh.write(in_data)
# 0 = success fh.close()
# 1-254 = remote command return code except (OSError, IOError):
# 255 = failure from the ssh command itself raise AnsibleConnectionFailure('SSH Error: data could not be sent to the remote host. Make sure this host can be reached over ssh')
if return_tuple[0] != 255 or attempt == (remaining_tries - 1):
break
else:
raise AnsibleConnectionFailure("Failed to connect to the host via ssh.")
except (AnsibleConnectionFailure, Exception) as e:
if attempt == remaining_tries - 1:
raise e
else:
pause = 2 ** attempt - 1
if pause > 30:
pause = 30
if isinstance(e, AnsibleConnectionFailure): self._display.debug('Sent initial data (%d bytes)' % len(in_data))
msg = "ssh_retry: attempt: %d, ssh return code is 255. cmd (%s), pausing for %d seconds" % (attempt, cmd_summary, pause)
else:
msg = "ssh_retry: attempt: %d, caught exception(%s) from cmd (%s), pausing for %d seconds" % (attempt, e, cmd_summary, pause)
self._display.vv(msg) # 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
time.sleep(pause) # This is separate from _run() because we need to do the same thing for stdout
continue # and stderr.
def _examine_output(self, source, state, 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.
return return_tuple Returns the processed (i.e. possibly-edited) output and the unprocessed
remainder (to be processed with the next chunk) as strings.
'''
def _exec_command(self, cmd, in_data=None, sudoable=True): output = []
''' run a command on the remote host ''' for l in chunk.splitlines(True):
suppress_output = False
super(Connection, self).exec_command(cmd, in_data=in_data, sudoable=sudoable) # self._display.debug("Examining line (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
if self._play_context.prompt and self.check_password_prompt(l):
self._display.debug("become_prompt: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_prompt'] = True
suppress_output = True
elif self._play_context.success_key and self.check_become_success(l):
self._display.debug("become_success: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_success'] = True
suppress_output = True
elif sudoable and self.check_incorrect_password(l):
self._display.debug("become_error: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_error'] = True
elif sudoable and self.check_missing_password(l):
self._display.debug("become_nopasswd_error: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_nopasswd_error'] = True
self._display.vvv("ESTABLISH SSH CONNECTION FOR USER: {0}".format(self._play_context.remote_user), host=self._play_context.remote_addr) if not suppress_output:
output.append(l)
# we can only use tty when we are not pipelining the modules. piping # The chunk we read was most likely a series of complete lines, but just
# data into /usr/bin/python inside a tty automatically invokes the # in case the last line was incomplete (and not a prompt, which we would
# python interactive-mode but the modules are not compatible with the # have removed from the output), we retain it to be processed with the
# interactive-mode ("unexpected indent" mainly because of empty lines) # next chunk.
if in_data: remainder = ''
cmd = self._build_command('ssh', self.host, cmd) if output and not output[-1].endswith('\n'):
else: remainder = output[-1]
cmd = self._build_command('ssh', '-tt', self.host, cmd) output = output[:-1]
(returncode, stdout, stderr) = self._run(cmd, in_data, sudoable=sudoable) return ''.join(output), remainder
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)
self._display.vvv("PUT {0} TO {1}".format(in_path, out_path), host=self.host)
if not os.path.exists(in_path):
raise AnsibleFileNotFound("file or module does not exist: {0}".format(in_path))
# scp and sftp require square brackets for IPv6 addresses, but
# accept them for hostnames and IPv4 addresses too.
host = '[%s]' % self.host
if C.DEFAULT_SCP_IF_SSH:
cmd = self._build_command('scp', in_path, '{0}:{1}'.format(host, pipes.quote(out_path)))
in_data = None
else:
cmd = self._build_command('sftp', host)
in_data = "put {0} {1}\n".format(pipes.quote(in_path), pipes.quote(out_path))
(returncode, stdout, stderr) = self._run(cmd, in_data)
if returncode != 0:
raise AnsibleError("failed to transfer file to {0}:\n{1}\n{2}".format(out_path, stdout, stderr))
def fetch_file(self, in_path, out_path):
''' fetch a file from remote to local '''
super(Connection, self).fetch_file(in_path, out_path)
self._display.vvv("FETCH {0} TO {1}".format(in_path, out_path), host=self.host)
# scp and sftp require square brackets for IPv6 addresses, but
# accept them for hostnames and IPv4 addresses too.
host = '[%s]' % self.host
if C.DEFAULT_SCP_IF_SSH:
cmd = self._build_command('scp', '{0}:{1}'.format(host, pipes.quote(in_path)), out_path)
in_data = None
else:
cmd = self._build_command('sftp', host)
in_data = "get {0} {1}\n".format(pipes.quote(in_path), pipes.quote(out_path))
(returncode, stdout, stderr) = self._run(cmd, in_data)
if returncode != 0:
raise AnsibleError("failed to transfer file from {0}:\n{1}\n{2}".format(in_path, stdout, stderr))
def _run(self, cmd, in_data, sudoable=True): def _run(self, cmd, in_data, sudoable=True):
''' '''
@ -556,127 +558,131 @@ class Connection(ConnectionBase):
return (p.returncode, stdout, stderr) return (p.returncode, stdout, stderr)
def _send_initial_data(self, fh, in_data): def _exec_command(self, cmd, in_data=None, sudoable=True):
''' ''' run a command on the remote host '''
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.)
'''
self._display.debug('Sending initial data') super(Connection, self).exec_command(cmd, in_data=in_data, sudoable=sudoable)
self._display.vvv("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)
if in_data:
cmd = self._build_command('ssh', self.host, cmd)
else:
cmd = self._build_command('ssh', '-tt', self.host, cmd)
(returncode, stdout, stderr) = self._run(cmd, in_data, sudoable=sudoable)
return (returncode, stdout, stderr)
#
# Main public methods
#
def exec_command(self, *args, **kwargs):
"""
Wrapper around _exec_command to retry in the case of an ssh failure
Will retry if:
* an exception is caught
* ssh returns 255
Will not retry if
* remaining_tries is <2
* retries limit reached
"""
remaining_tries = int(C.ANSIBLE_SSH_RETRIES) + 1
cmd_summary = "%s..." % args[0]
for attempt in xrange(remaining_tries):
try: try:
fh.write(in_data) return_tuple = self._exec_command(*args, **kwargs)
fh.close() # 0 = success
except (OSError, IOError): # 1-254 = remote command return code
raise AnsibleConnectionFailure('SSH Error: data could not be sent to the remote host. Make sure this host can be reached over ssh') # 255 = failure from the ssh command itself
if return_tuple[0] != 255 or attempt == (remaining_tries - 1):
break
else:
raise AnsibleConnectionFailure("Failed to connect to the host via ssh.")
except (AnsibleConnectionFailure, Exception) as e:
if attempt == remaining_tries - 1:
raise e
else:
pause = 2 ** attempt - 1
if pause > 30:
pause = 30
self._display.debug('Sent initial data (%d bytes)' % len(in_data)) if isinstance(e, AnsibleConnectionFailure):
msg = "ssh_retry: attempt: %d, ssh return code is 255. cmd (%s), pausing for %d seconds" % (attempt, cmd_summary, pause)
else:
msg = "ssh_retry: attempt: %d, caught exception(%s) from cmd (%s), pausing for %d seconds" % (attempt, e, cmd_summary, pause)
# This is a separate method because we need to do the same thing for stdout self._display.vv(msg)
# and stderr.
def _examine_output(self, source, state, chunk, sudoable): time.sleep(pause)
''' continue
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 return return_tuple
remainder (to be processed with the next chunk) as strings.
'''
output = [] def put_file(self, in_path, out_path):
for l in chunk.splitlines(True): ''' transfer a file from local to remote '''
suppress_output = False
# self._display.debug("Examining line (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n'))) super(Connection, self).put_file(in_path, out_path)
if self._play_context.prompt and self.check_password_prompt(l):
self._display.debug("become_prompt: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_prompt'] = True
suppress_output = True
elif self._play_context.success_key and self.check_become_success(l):
self._display.debug("become_success: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_success'] = True
suppress_output = True
elif sudoable and self.check_incorrect_password(l):
self._display.debug("become_error: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_error'] = True
elif sudoable and self.check_missing_password(l):
self._display.debug("become_nopasswd_error: (source=%s, state=%s): '%s'" % (source, state, l.rstrip('\r\n')))
self._flags['become_nopasswd_error'] = True
if not suppress_output: self._display.vvv("PUT {0} TO {1}".format(in_path, out_path), host=self.host)
output.append(l) if not os.path.exists(in_path):
raise AnsibleFileNotFound("file or module does not exist: {0}".format(in_path))
# The chunk we read was most likely a series of complete lines, but just # scp and sftp require square brackets for IPv6 addresses, but
# in case the last line was incomplete (and not a prompt, which we would # accept them for hostnames and IPv4 addresses too.
# have removed from the output), we retain it to be processed with the host = '[%s]' % self.host
# next chunk.
remainder = '' if C.DEFAULT_SCP_IF_SSH:
if output and not output[-1].endswith('\n'): cmd = self._build_command('scp', in_path, '{0}:{1}'.format(host, pipes.quote(out_path)))
remainder = output[-1] in_data = None
output = output[:-1] else:
cmd = self._build_command('sftp', host)
in_data = "put {0} {1}\n".format(pipes.quote(in_path), pipes.quote(out_path))
return ''.join(output), remainder (returncode, stdout, stderr) = self._run(cmd, in_data)
# Utility functions if returncode != 0:
raise AnsibleError("failed to transfer file to {0}:\n{1}\n{2}".format(out_path, stdout, stderr))
def _sshpass_available(self): def fetch_file(self, in_path, out_path):
global SSHPASS_AVAILABLE ''' fetch a file from remote to local '''
# We test once if sshpass is available, and remember the result. It super(Connection, self).fetch_file(in_path, out_path)
# 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: self._display.vvv("FETCH {0} TO {1}".format(in_path, out_path), host=self.host)
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 # scp and sftp require square brackets for IPv6 addresses, but
# accept them for hostnames and IPv4 addresses too.
host = '[%s]' % self.host
def _persistence_controls(self, command): if C.DEFAULT_SCP_IF_SSH:
''' cmd = self._build_command('scp', '{0}:{1}'.format(host, pipes.quote(in_path)), out_path)
Takes a command array and scans it for ControlPersist and ControlPath in_data = None
settings and returns two booleans indicating whether either was found. else:
This could be smarter, e.g. returning false if ControlPersist is 'no', cmd = self._build_command('sftp', host)
but for now we do it simple way. in_data = "get {0} {1}\n".format(pipes.quote(in_path), pipes.quote(out_path))
'''
controlpersist = False (returncode, stdout, stderr) = self._run(cmd, in_data)
controlpath = False
for arg in command: if returncode != 0:
if 'controlpersist' in arg.lower(): raise AnsibleError("failed to transfer file from {0}:\n{1}\n{2}".format(in_path, stdout, stderr))
controlpersist = True
elif 'controlpath' in arg.lower():
controlpath = True
return controlpersist, controlpath def close(self):
# If we have a persistent ssh connection (ControlPersist), we can ask it
# to stop listening. Otherwise, there's nothing to do here.
def _terminate_process(self, p): # TODO: reenable once winrm issues are fixed
try: # temporarily disabled as we are forced to currently close connections after every task because of winrm
p.terminate() # if self._connected and self._persistent:
except (OSError, IOError): # cmd = self._build_command('ssh', '-O', 'stop', self.host)
pass # p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
# stdout, stderr = p.communicate()
def _split_args(self, argstring): self._connected = False
"""
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.
"""
return [x.strip() for x in shlex.split(argstring) if x.strip()]
def add_args(self, explanation, args):
"""
Adds the given args to self._command and displays a caller-supplied
explanation of why they were added.
"""
self._command += args
self._display.vvvvv('SSH: ' + explanation + ': (%s)' % ')('.join(args), host=self._play_context.remote_addr)