def go():
while True:
try:
s = Session()
s.options_set(options.HOST, HOST)
s.connect()
sleep(2147483647)
except Exception as e:
global count
print(str(e) + ': died #' + str(count))
if 'Connection reset' in str(e):
break
count += 1
pass
class SSHTestCase(unittest.TestCase):
@classmethod
def sign_cert(cls):
cmd = [
'ssh-keygen',
'-s',
CA_USER_KEY,
'-n',
USER,
'-I',
'tests',
USER_CERT_PUB_KEY,
]
subprocess.check_call(cmd)
@classmethod
def setUpClass(cls):
_mask = int('0600') if version_info <= (2, ) else 0o600
for _file in [PKEY_FILENAME, USER_CERT_PRIV_KEY, CA_USER_KEY]:
os.chmod(_file, _mask)
cls.sign_cert()
cls.server = OpenSSHServer()
cls.server.start_server()
@classmethod
def tearDownClass(cls):
cls.server.stop()
del cls.server
def setUp(self):
self.host = '127.0.0.1'
self.port = 2222
self.cmd = 'echo me'
self.resp = u'me'
self.user_key = PKEY_FILENAME
self.user_pub_key = PUB_FILE
self.user_ca_key = USER_CERT_PRIV_KEY
self.user_cert_file = USER_CERT_FILE
self.user = USER
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((self.host, self.port))
self.sock = sock
self.session = Session()
self.session.options_set(options.HOST, self.host)
self.session.options_set_port(self.port)
self.session.options_set(options.USER, self.user)
self.session.set_socket(sock)
self.pkey = import_privkey_file(self.user_key)
# self.session.options_set(options.LOG_VERBOSITY, '1')
def tearDown(self):
del self.session
def _auth(self):
self.assertEqual(self.session.connect(), 0)
self.assertEqual(self.session.userauth_publickey(self.pkey), 0)
def test_non_blocking_connect(self):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((self.host, self.port))
session = Session()
session.options_set(options.USER, self.user)
session.options_set(options.HOST, self.host)
session.options_set_port(self.port)
self.assertEqual(session.set_socket(sock), 0)
session.set_blocking(0)
rc = session.connect()
while rc == SSH_AGAIN:
wait_socket(session, sock)
rc = session.connect()
self.assertEqual(rc, 0)
rc = session.userauth_publickey(self.pkey)
while rc == SSH_AUTH_AGAIN:
wait_socket(session, sock)
rc = session.userauth_publickey(self.pkey)
self.assertEqual(rc, 0)
def test_socket_connect(self):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((self.host, self.port))
session = Session()
session.options_set(options.USER, self.user)
session.options_set(options.HOST, self.host)
session.options_set_port(self.port)
self.assertEqual(session.set_socket(sock), 0)
self.assertEqual(session.connect(), 0)
self.assertRaises(RequestDenied, session.userauth_none)
self.assertEqual(session.userauth_publickey(self.pkey), 0)
class SSHTestCase(unittest.TestCase):
@classmethod
def setUpClass(cls):
_mask = int('0600') if version_info <= (2,) else 0o600
os.chmod(PKEY_FILENAME, _mask)
cls.server = OpenSSHServer()
cls.server.start_server()
@classmethod
def tearDownClass(cls):
cls.server.stop()
del cls.server
def setUp(self):
self.host = '127.0.0.1'
self.port = 2222
self.cmd = 'echo me'
self.resp = u'me'
self.user_key = PKEY_FILENAME
self.user_pub_key = PUB_FILE
self.user = pwd.getpwuid(os.geteuid()).pw_name
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((self.host, self.port))
self.sock = sock
self.session = Session()
self.session.options_set(options.HOST, self.host)
self.session.options_set_port(self.port)
self.session.options_set(options.USER, self.user)
self.session.set_socket(sock)
self.pkey = import_privkey_file(self.user_key)
# self.session.options_set(options.LOG_VERBOSITY, '1')
def tearDown(self):
del self.session
def _auth(self):
self.assertEqual(self.session.connect(), 0)
self.assertEqual(
self.session.userauth_publickey(self.pkey), 0)
class SSHClient(BaseSSHClient):
"""ssh-python based non-blocking client."""
def __init__(self,
host,
user=None,
password=None,
port=None,
pkey=None,
cert_file=None,
num_retries=DEFAULT_RETRIES,
retry_delay=RETRY_DELAY,
allow_agent=True,
timeout=None,
identity_auth=True,
gssapi_auth=False,
gssapi_server_identity=None,
gssapi_client_identity=None,
gssapi_delegate_credentials=False,
_auth_thread_pool=True):
""":param host: Host name or IP to connect to.
:type host: str
:param user: User to connect as. Defaults to logged in user.
:type user: str
:param password: Password to use for password authentication.
:type password: str
:param port: SSH port to connect to. Defaults to SSH default (22)
:type port: int
:param pkey: Private key file path to use for authentication. Path must
be either absolute path or relative to user home directory
like ``~/<path>``.
:type pkey: str
:param cert_file: Public key signed certificate file to use for
authentication. The corresponding private key must also be provided
via ``pkey`` parameter.
For example ``pkey='id_rsa',cert_file='id_rsa-cert.pub'`` for RSA
signed certificate.
Path must be absolute or relative to user home directory.
:type cert_file: str
:param num_retries: (Optional) Number of connection and authentication
attempts before the client gives up. Defaults to 3.
:type num_retries: int
:param retry_delay: Number of seconds to wait between retries. Defaults
to :py:class:`pssh.constants.RETRY_DELAY`
:type retry_delay: int
:param timeout: (Optional) If provided, all commands will timeout after
<timeout> number of seconds.
:type timeout: int
:param allow_agent: (Optional) set to False to disable connecting to
the system's SSH agent. Currently unused.
:type allow_agent: bool
:param identity_auth: (Optional) set to False to disable attempting to
authenticate with default identity files from
`pssh.clients.base_ssh_client.BaseSSHClient.IDENTITIES`
:type identity_auth: bool
:param gssapi_server_identity: Enable GSS-API authentication.
Uses GSS-MIC key exchange. Enabled if either gssapi_server_identity or
gssapi_client_identity are provided.
:type gssapi_auth: bool
:type gssapi_server_identity: str
:param gssapi_server_identity: Set GSSAPI server identity.
:type gssapi_server_identity: str
:param gssapi_client_identity: Set GSSAPI client identity.
:type gssapi_client_identity: str
:param gssapi_delegate_credentials: Enable/disable server credentials
delegation.
:type gssapi_delegate_credentials: bool
:raises: :py:class:`pssh.exceptions.PKeyFileError` on errors finding
provided private key.
"""
self.cert_file = _validate_pkey_path(cert_file, host)
self.gssapi_auth = gssapi_auth
self.gssapi_server_identity = gssapi_server_identity
self.gssapi_client_identity = gssapi_client_identity
self.gssapi_delegate_credentials = gssapi_delegate_credentials
super(SSHClient, self).__init__(host,
user=user,
password=password,
port=port,
pkey=pkey,
num_retries=num_retries,
retry_delay=retry_delay,
allow_agent=allow_agent,
_auth_thread_pool=_auth_thread_pool,
timeout=timeout,
identity_auth=identity_auth)
def disconnect(self):
"""Close socket if needed."""
if self.sock is not None and not self.sock.closed:
self.sock.close()
def _agent_auth(self):
self.session.userauth_agent(self.user)
def _keepalive(self):
pass
def _init_session(self, retries=1):
logger.debug("Starting new session for %s@%s:%s", self.user, self.host,
self.port)
self.session = Session()
self.session.options_set(options.USER, self.user)
self.session.options_set(options.HOST, self.host)
self.session.options_set_port(self.port)
if self.gssapi_server_identity:
self.session.options_set(options.GSSAPI_SERVER_IDENTITY,
self.gssapi_server_identity)
if self.gssapi_client_identity:
self.session.options_set(options.GSSAPI_CLIENT_IDENTITY,
self.gssapi_client_identity)
if self.gssapi_client_identity or self.gssapi_server_identity:
self.session.options_set_gssapi_delegate_credentials(
self.gssapi_delegate_credentials)
self.session.set_socket(self.sock)
logger.debug("Session started, connecting with existing socket")
try:
self._session_connect()
except Exception as ex:
if retries < self.num_retries:
return self._connect_init_session_retry(retries=retries + 1)
msg = "Error connecting to host %s:%s - %s"
logger.error(msg, self.host, self.port, ex)
ex.host = self.host
ex.port = self.port
raise ex
def _session_connect(self):
self.session.connect()
def auth(self):
if self.gssapi_auth or (self.gssapi_server_identity
or self.gssapi_client_identity):
try:
return self.session.userauth_gssapi()
except Exception as ex:
logger.error(
"GSSAPI authentication with server id %s and client id %s failed - %s",
self.gssapi_server_identity, self.gssapi_client_identity,
ex)
return super(SSHClient, self).auth()
def _password_auth(self):
self.session.userauth_password(self.user, self.password)
def _pkey_auth(self, pkey_file, password=None):
pkey = import_privkey_file(
pkey_file, passphrase=password if password is not None else '')
if self.cert_file is not None:
logger.debug(
"Certificate file set - trying certificate authentication")
self._import_cert_file(pkey)
self.session.userauth_publickey(pkey)
def _import_cert_file(self, pkey):
cert_key = import_cert_file(self.cert_file)
self.session.userauth_try_publickey(cert_key)
copy_cert_to_privkey(cert_key, pkey)
logger.debug("Imported certificate file %s for pkey %s",
self.cert_file, self.pkey)
def _shell(self, channel):
return self._eagain(channel.request_shell)
def _open_session(self):
channel = self.session.channel_new()
channel.set_blocking(0)
self._eagain(channel.open_session)
return channel
def open_session(self):
"""Open new channel from session."""
logger.debug("Opening new channel on %s", self.host)
try:
channel = self._open_session()
except Exception as ex:
raise SessionError(ex)
return channel
def _make_output_readers(self, channel, stdout_buffer, stderr_buffer):
_stdout_reader = spawn(self._read_output_to_buffer, channel,
stdout_buffer)
_stderr_reader = spawn(self._read_output_to_buffer,
channel,
stderr_buffer,
is_stderr=True)
return _stdout_reader, _stderr_reader
def execute(self, cmd, use_pty=False, channel=None):
"""Execute command on remote host.
:param cmd: The command string to execute.
:type cmd: str
:param use_pty: Whether or not to request a PTY on the channel executing
command.
:type use_pty: bool
:param channel: Channel to use. New channel is created if not provided.
:type channel: :py:class:`ssh.channel.Channel`"""
channel = self.open_session() if not channel else channel
if use_pty:
self._eagain(channel.request_pty, timeout=self.timeout)
logger.debug("Executing command '%s'", cmd)
self._eagain(channel.request_exec, cmd, timeout=self.timeout)
return channel
def _read_output_to_buffer(self, channel, _buffer, is_stderr=False):
while True:
self.poll(timeout=self.timeout)
try:
size, data = channel.read_nonblocking(is_stderr=is_stderr)
except EOF:
_buffer.eof.set()
sleep(.1)
return
if size > 0:
_buffer.write(data)
else:
# Yield event loop to other greenlets if we have no data to
# send back, meaning the generator does not yield and can there
# for block other generators/greenlets from running.
sleep(.1)
def wait_finished(self, host_output, timeout=None):
"""Wait for EOF from channel and close channel.
Used to wait for remote command completion and be able to gather
exit code.
:param host_output: Host output of command to wait for.
:type host_output: :py:class:`pssh.output.HostOutput`
:param timeout: Timeout value in seconds - defaults to no timeout.
:type timeout: float
:raises: :py:class:`pssh.exceptions.Timeout` after <timeout> seconds if
timeout set.
"""
if not isinstance(host_output, HostOutput):
raise ValueError("%s is not a HostOutput object" % (host_output, ))
channel = host_output.channel
if channel is None:
return
logger.debug("Sending EOF on channel %s", channel)
self._eagain(channel.send_eof, timeout=self.timeout)
logger.debug("Waiting for readers, timeout %s", timeout)
with GTimeout(seconds=timeout, exception=Timeout):
joinall((host_output.buffers.stdout.reader,
host_output.buffers.stderr.reader))
logger.debug("Readers finished, closing channel")
self.close_channel(channel)
def finished(self, channel):
"""Checks if remote command has finished - has server sent client
EOF.
:rtype: bool
"""
if channel is None:
return
return channel.is_eof()
def get_exit_status(self, channel):
"""Get exit status code for channel or ``None`` if not ready.
:param channel: The channel to get status from.
:type channel: :py:mod:`ssh.channel.Channel`
:rtype: int or ``None``
"""
if not channel.is_eof():
return
return channel.get_exit_status()
def close_channel(self, channel):
"""Close channel.
:param channel: The channel to close.
:type channel: :py:class:`ssh.channel.Channel`
"""
logger.debug("Closing channel")
self._eagain(channel.close, timeout=self.timeout)
def poll(self, timeout=None):
"""ssh-python based co-operative gevent poll on session socket."""
self._poll_errcodes(
self.session.get_poll_flags,
SSH_READ_PENDING,
SSH_WRITE_PENDING,
timeout=timeout,
)
def _eagain(self, func, *args, **kwargs):
"""Run function given and handle EAGAIN for an ssh-python session"""
return self._eagain_errcode(func, SSH_AGAIN, *args, **kwargs)
def _eagain_write(self, write_func, data, timeout=None):
return self._eagain_write_errcode(write_func,
data,
SSH_AGAIN,
timeout=timeout)
class SSHConnect:
"""Context manager to remotely connect to servers using libssh.
The connection manager requires an SSH key to be defined, and exist,
however, upon enter the system will use the SSH agent is defined.
"""
def __init__(self, host, username, port, key_file=None, debug=False):
"""Initialize the connection manager.
:param host: IP or Domain to connect to.
:type host: String
:param username: Username for the connection.
:type username: String
:param port: Port number used to connect to the remote server.
:type port: Int
:param key_file: SSH key file used to connect.
:type key_file: String
:param debug: Enable or disable debug mode
:type debug: Boolean
"""
self.log = logger.getLogger(name="directord-ssh", debug_logging=debug)
self.key_file = key_file
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.connect((host, port))
self.session = Session()
self.session.options_set(options.HOST, host)
self.session.options_set(options.USER, username)
self.session.options_set_port(port)
self.session.set_socket(self.sock)
self.session.connect()
self.log.debug("Handshake with [ %s ] on port [ %s ] complete.", host,
port)
self.channels = dict()
self.host = host
self.username = username
self.key_file = key_file
def _userauth_publickey_fromfile(self, key_file):
"""Import a private key file.
:param key_file: Fully qualified path to an ssh key file.
:type key_file: String
"""
key = ssh_key.import_privkey_file(key_file)
self.session.userauth_publickey(key)
def set_auth(self):
"""Set the ssh session auth."""
if self.key_file:
self._userauth_publickey_fromfile(key_file=self.key_file)
self.log.debug("Key file [ %s ] added", self.key_file)
else:
try:
self.session.userauth_agent(self.username)
self.log.debug("User agent based authentication enabled")
except Exception as e:
self.log.warning(
"SSH Agent connection has failed: %s."
" Attempting to connect with the user's implicit ssh key.",
str(e),
)
home = os.path.abspath(os.path.expanduser("~"))
default_keyfile = os.path.join(home, ".ssh/id_rsa")
if os.path.exists(default_keyfile):
self._userauth_publickey_fromfile(key_file=default_keyfile)
self.log.debug("Implicit key file [ %s ] added",
self.key_file)
else:
self.log.critical(
"No implicit key found [ %s ]. Setup user-agent"
" authentication or use the --key-file"
" argument to explicitly set the required"
" ssh key.",
default_keyfile,
)
raise SystemExit("Authentication failure")
def __enter__(self):
"""Connect to the remote node and return the ssh and session objects.
:returns: Tuple
"""
self.set_auth()
return self
def __exit__(self, *args, **kwargs):
"""Upon exit, close the ssh connection."""
for key, value in self.channels.items():
if hasattr(value, "close"):
value.close()
self.log.debug("%s channel is closed.", key)
self.session.disconnect()
self.log.debug("SSH session is closed.")
from ssh.session import Session
from ssh import options
# Linux only
USERNAME = pwd.getpwuid(os.geteuid()).pw_name
HOST = 'localhost'
PORT = 22
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((HOST, PORT))
s = Session()
s.options_set(options.HOST, HOST)
s.options_set(options.USER, USERNAME)
s.options_set_port(PORT)
s.set_socket(sock)
s.connect()
# Authenticate with agent
s.userauth_agent(USERNAME)
chan = s.channel_new()
chan.open_session()
chan.request_exec('echo me')
size, data = chan.read()
while size > 0:
print(data.strip())
size, data = chan.read()
chan.close()
class SSHClient(BaseSSHClient):
"""ssh-python based non-blocking client."""
def __init__(self,
host,
user=None,
password=None,
port=None,
pkey=None,
num_retries=DEFAULT_RETRIES,
retry_delay=RETRY_DELAY,
allow_agent=True,
timeout=None,
identity_auth=True,
gssapi_auth=False,
gssapi_server_identity=None,
gssapi_client_identity=None,
gssapi_delegate_credentials=False,
_auth_thread_pool=True):
""":param host: Host name or IP to connect to.
:type host: str
:param user: User to connect as. Defaults to logged in user.
:type user: str
:param password: Password to use for password authentication.
:type password: str
:param port: SSH port to connect to. Defaults to SSH default (22)
:type port: int
:param pkey: Private key file path to use for authentication. Path must
be either absolute path or relative to user home directory
like ``~/<path>``.
:type pkey: str
:param num_retries: (Optional) Number of connection and authentication
attempts before the client gives up. Defaults to 3.
:type num_retries: int
:param retry_delay: Number of seconds to wait between retries. Defaults
to :py:class:`pssh.constants.RETRY_DELAY`
:type retry_delay: int
:param timeout: (Optional) If provided, all commands will timeout after
<timeout> number of seconds.
:type timeout: int
:param allow_agent: (Optional) set to False to disable connecting to
the system's SSH agent. Currently unused.
:type allow_agent: bool
:param identity_auth: (Optional) set to False to disable attempting to
authenticate with default identity files from
`pssh.clients.base_ssh_client.BaseSSHClient.IDENTITIES`
:type identity_auth: bool
:param gssapi_server_identity: Enable GSS-API authentication.
Uses GSS-MIC key exchange. Enabled if either gssapi_server_identity or
gssapi_client_identity are provided.
:type gssapi_auth: bool
:type gssapi_server_identity: str
:param gssapi_server_identity: Set GSSAPI server identity.
:type gssapi_server_identity: str
:param gssapi_client_identity: Set GSSAPI client identity.
:type gssapi_client_identity: str
:param gssapi_delegate_credentials: Enable/disable server credentials
delegation.
:type gssapi_delegate_credentials: bool
:raises: :py:class:`pssh.exceptions.PKeyFileError` on errors finding
provided private key.
"""
self.gssapi_auth = gssapi_auth
self.gssapi_server_identity = gssapi_server_identity
self.gssapi_client_identity = gssapi_client_identity
self.gssapi_delegate_credentials = gssapi_delegate_credentials
super(SSHClient, self).__init__(host,
user=user,
password=password,
port=port,
pkey=pkey,
num_retries=num_retries,
retry_delay=retry_delay,
allow_agent=allow_agent,
_auth_thread_pool=_auth_thread_pool,
timeout=timeout,
identity_auth=identity_auth)
self._stdout_buffer = BytesIO()
self._stderr_buffer = BytesIO()
self._stdout_reader = None
self._stderr_reader = None
self._stdout_read = False
self._stderr_read = False
def disconnect(self):
"""Close socket if needed."""
if self.sock is not None and not self.sock.closed:
logger.debug("Closing socket")
self.sock.close()
def _init(self, retries=1):
logger.debug("Starting new session for %s@%s:%s", self.user, self.host,
self.port)
self.session = Session()
self.session.options_set(options.USER, self.user)
self.session.options_set(options.HOST, self.host)
self.session.options_set_port(self.port)
if self.gssapi_server_identity:
self.session.options_set(options.GSSAPI_SERVER_IDENTITY,
self.gssapi_server_identity)
if self.gssapi_client_identity:
self.session.options_set(options.GSSAPI_CLIENT_IDENTITY,
self.gssapi_client_identity)
if self.gssapi_client_identity or self.gssapi_server_identity:
self.session.options_set_gssapi_delegate_credentials(
self.gssapi_delegate_credentials)
self.session.set_socket(self.sock)
logger.debug("Session started, connecting with existing socket")
try:
self.session.connect()
except Exception as ex:
while retries < self.num_retries:
return self._connect_init_retry(retries)
msg = "Error connecting to host %s:%s - %s"
logger.error(msg, self.host, self.port, ex)
ex.host = self.host
ex.port = self.port
raise ex
try:
self.auth()
except Exception as ex:
while retries < self.num_retries:
return self._connect_init_retry(retries)
msg = "Authentication error while connecting to %s:%s - %s"
ex = AuthenticationException(msg, self.host, self.port, ex)
ex.host = self.host
ex.port = self.port
raise ex
logger.debug("Authentication completed successfully - "
"setting session to non-blocking mode")
self.session.set_blocking(0)
def auth(self):
if self.pkey is not None:
logger.debug("Proceeding with private key file authentication")
return self._pkey_auth(self.pkey, self.password)
if self.allow_agent:
try:
self.session.userauth_agent(self.user)
except Exception as ex:
logger.debug(
"Agent auth failed with %s, "
"continuing with other authentication methods", ex)
else:
logger.debug("Authentication with SSH Agent succeeded.")
return
if self.gssapi_auth or (self.gssapi_server_identity
or self.gssapi_client_identity):
try:
self.session.userauth_gssapi()
except Exception as ex:
logger.error(
"GSSAPI authentication with server id %s and client id %s failed - %s",
self.gssapi_server_identity, self.gssapi_client_identity,
ex)
if self.identity_auth:
try:
self._identity_auth()
except AuthenticationException:
if self.password is None:
raise
logger.debug("Private key auth failed, trying password")
self._password_auth()
def _password_auth(self):
if not self.password:
raise AuthenticationException("All authentication methods failed")
try:
self.session.userauth_password(self.password)
except Exception as ex:
raise AuthenticationException(
"Password authentication failed - %s", ex)
def _pkey_auth(self, pkey, password=None):
password = b'' if not password else password
pkey = import_privkey_file(pkey, passphrase=password)
self.session.userauth_publickey(pkey)
def open_session(self):
"""Open new channel from session."""
logger.debug("Opening new channel on %s", self.host)
try:
channel = self.session.channel_new()
while channel == SSH_AGAIN:
wait_select(self.session, timeout=self.timeout)
channel = self.session.channel_new()
logger.debug("Channel %s created, opening session", channel)
channel.set_blocking(0)
while channel.open_session() == SSH_AGAIN:
logger.debug(
"Channel open session blocked, waiting on socket..")
wait_select(self.session, timeout=self.timeout)
# Select on open session can dead lock without
# yielding event loop
sleep(.1)
except Exception as ex:
raise SessionError(ex)
return channel
def execute(self, cmd, use_pty=False, channel=None):
"""Execute command on remote host.
:param cmd: The command string to execute.
:type cmd: str
:param use_pty: Whether or not to request a PTY on the channel executing
command.
:type use_pty: bool
:param channel: Channel to use. New channel is created if not provided.
:type channel: :py:class:`ssh.channel.Channel`"""
channel = self.open_session() if not channel else channel
if use_pty:
eagain(self.session, channel.request_pty, timeout=self.timeout)
eagain(self.session, channel.request_exec, cmd, timeout=self.timeout)
self._stderr_read = False
self._stdout_read = False
self._stdout_buffer = BytesIO()
self._stderr_buffer = BytesIO()
self._stdout_reader = spawn(self._read_output_to_buffer, channel)
self._stderr_reader = spawn(self._read_output_to_buffer,
channel,
is_stderr=True)
self._stdout_reader.start()
self._stderr_reader.start()
return channel
def read_stderr(self, channel, timeout=None):
"""Read standard error buffer from channel.
Returns a generator of line by line output.
:param channel: Channel to read output from.
:type channel: :py:class:`ssh2.channel.Channel`
:rtype: generator
"""
_buffer_name = 'stderr'
_buffer = self._stderr_buffer
_flag = self._stderr_read
_reader = self._stderr_reader
return self._read_output(_buffer,
_buffer_name,
_flag,
_reader,
channel,
timeout=timeout,
is_stderr=True)
def read_output(self, channel, timeout=None, is_stderr=False):
"""Read standard output buffer from channel.
Returns a generator of line by line output.
:param channel: Channel to read output from.
:type channel: :py:class:`ssh2.channel.Channel`
:rtype: generator
"""
_buffer_name = 'stdout'
_buffer = self._stdout_buffer
_flag = self._stdout_read
_reader = self._stdout_reader
return self._read_output(_buffer,
_buffer_name,
_flag,
_reader,
channel,
timeout=timeout)
def _read_output(self,
_buffer,
_buffer_name,
_flag,
_reader,
channel,
timeout=None,
is_stderr=False):
if _flag is True:
logger.debug("Output for %s has already been read", _buffer_name)
raise StopIteration
logger.debug("Waiting for %s reader", _buffer_name)
timeout = timeout if timeout else self.timeout
try:
_reader.get(timeout=timeout)
except GeventTimeout as ex:
raise Timeout(ex)
if _buffer.getvalue() == '':
logger.debug("Reader finished and output empty for %s",
_buffer_name)
raise StopIteration
logger.debug("Reading from %s buffer", _buffer_name)
for line in _buffer.getvalue().splitlines():
yield line
if is_stderr:
self._stderr_read = True
else:
self._stdout_read = True
def _read_output_to_buffer(self, channel, is_stderr=False):
_buffer_name = 'stderr' if is_stderr else 'stdout'
_buffer = self._stderr_buffer if is_stderr else self._stdout_buffer
logger.debug("Starting output generator on channel %s for %s", channel,
_buffer_name)
while True:
wait_select(self.session, timeout=self.timeout)
try:
size, data = channel.read_nonblocking(is_stderr=is_stderr)
except EOF:
logger.debug(
"Channel is at EOF trying to read %s - "
"reader exiting", _buffer_name)
sleep(.1)
return
if size > 0:
logger.debug("Writing %s bytes to %s buffer", size,
_buffer_name)
_buffer.write(data)
else:
# Yield event loop to other greenlets if we have no data to
# send back, meaning the generator does not yield and can there
# for block other generators/greenlets from running.
logger.debug("No data for %s, waiting", _buffer_name)
sleep(.1)
def wait_finished(self, channel, timeout=None):
"""Wait for EOF from channel and close channel.
Used to wait for remote command completion and be able to gather
exit code.
:param channel: The channel to use.
:type channel: :py:class:`ssh.channel.Channel`
"""
if channel is None:
return
timeout = timeout if timeout else self.timeout
logger.debug("Sending EOF on channel %s", channel)
eagain(self.session, channel.send_eof, timeout=timeout)
try:
self._stdout_reader.get(timeout=timeout)
self._stderr_reader.get(timeout=timeout)
except GeventTimeout as ex:
logger.debug("Timed out waiting for readers..")
raise Timeout(ex)
else:
logger.debug("Readers finished, closing channel")
# Close channel
self.close_channel(channel)
def finished(self, channel):
"""Checks if remote command has finished - has server sent client
EOF.
:rtype: bool
"""
if channel is None:
return
return channel.is_eof()
def get_exit_status(self, channel):
"""Get exit status from channel if ready else return `None`.
:rtype: int or `None`
"""
if not channel.is_eof():
return
return channel.get_exit_status()
def close_channel(self, channel):
"""Close channel.
:param channel: The channel to close.
:type channel: :py:class:`ssh.channel.Channel`
"""
logger.debug("Closing channel")
eagain(self.session, channel.close, timeout=self.timeout)