neutron-tempest-plugin/neutron_tempest_plugin/common/ssh.py

300 lines
12 KiB
Python

# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import locale
import os
import socket
import time
from oslo_log import log
import paramiko
from tempest.lib.common import ssh
from tempest.lib import exceptions
import tenacity
from neutron_tempest_plugin import config
from neutron_tempest_plugin import exceptions as exc
CONF = config.CONF
LOG = log.getLogger(__name__)
RETRY_EXCEPTIONS = (exceptions.TimeoutException, paramiko.SSHException,
socket.error, TimeoutError)
class Client(ssh.Client):
default_ssh_lang = 'en_US.UTF-8'
timeout = CONF.validation.ssh_timeout
proxy_jump_host = CONF.neutron_plugin_options.ssh_proxy_jump_host
proxy_jump_username = CONF.neutron_plugin_options.ssh_proxy_jump_username
proxy_jump_password = CONF.neutron_plugin_options.ssh_proxy_jump_password
proxy_jump_keyfile = CONF.neutron_plugin_options.ssh_proxy_jump_keyfile
proxy_jump_port = CONF.neutron_plugin_options.ssh_proxy_jump_port
def __init__(self, host, username, password=None, timeout=None, pkey=None,
channel_timeout=10, look_for_keys=False, key_filename=None,
port=22, proxy_client=None, create_proxy_client=True):
timeout = timeout or self.timeout
if not proxy_client and create_proxy_client and self.proxy_jump_host:
# Perform all SSH connections passing through configured SSH server
proxy_client = self.create_proxy_client(
timeout=timeout, channel_timeout=channel_timeout)
super(Client, self).__init__(
host=host, username=username, password=password, timeout=timeout,
pkey=pkey, channel_timeout=channel_timeout,
look_for_keys=look_for_keys, key_filename=key_filename, port=port,
proxy_client=proxy_client)
@classmethod
def create_proxy_client(cls, look_for_keys=True, **kwargs):
host = cls.proxy_jump_host
if not host:
# proxy_jump_host string cannot be empty or None
raise ValueError(
"'proxy_jump_host' configuration option is empty.")
# Let accept an empty string as a synonymous of default value on below
# options
password = cls.proxy_jump_password or None
key_file = cls.proxy_jump_keyfile or None
username = cls.proxy_jump_username
# Port must be a positive integer
port = cls.proxy_jump_port
if port <= 0 or port > 65535:
raise ValueError(
"Invalid value for 'proxy_jump_port' configuration option: "
"{!r}".format(port))
login = "{username}@{host}:{port}".format(username=username, host=host,
port=port)
if key_file:
# expand ~ character with user HOME directory
key_file = os.path.expanduser(key_file)
if os.path.isfile(key_file):
LOG.debug("Going to create SSH connection to %r using key "
"file: %s", login, key_file)
else:
# This message could help the user to identify a
# mis-configuration in tempest.conf
raise ValueError(
"Cannot find file specified as 'proxy_jump_keyfile' "
"option: {!r}".format(key_file))
elif password:
LOG.debug("Going to create SSH connection to %r using password.",
login)
elif look_for_keys:
# This message could help the user to identify a mis-configuration
# in tempest.conf
LOG.info("Both 'proxy_jump_password' and 'proxy_jump_keyfile' "
"options are empty. Going to create SSH connection to %r "
"looking for key file location into %r directory.",
login, os.path.expanduser('~/.ssh'))
else:
# An user that forces look_for_keys=False should really know what
# he really wants
LOG.warning("No authentication method provided to create an SSH "
"connection to %r. If it fails, then please "
"set 'proxy_jump_keyfile' to provide a valid SSH key "
"file.", login)
return Client(
host=host, username=username, password=password,
look_for_keys=look_for_keys, key_filename=key_file,
port=port, create_proxy_client=False, **kwargs)
def connect(self, *args, **kwargs):
"""Creates paramiko.SSHClient and connect it to remote SSH server
:returns: paramiko.Client connected to remote server.
:raises tempest.lib.exceptions.SSHTimeout: in case it fails to connect
to remote server.
"""
return super(Client, self)._get_ssh_connection(*args, **kwargs)
# This overrides superclass test_connection_auth method forbidding it to
# close connection
test_connection_auth = connect
def open_session(self):
"""Gets connection to SSH server and open a new paramiko.Channel
:returns: new paramiko.Channel
"""
client = self.connect()
try:
return client.get_transport().open_session()
except paramiko.SSHException:
# the request is rejected, the session ends prematurely or
# there is a timeout opening a channel
LOG.exception("Unable to open SSH session")
raise exceptions.SSHTimeout(host=self.host,
user=self.username,
password=self.password)
@tenacity.retry(
stop=tenacity.stop_after_attempt(10),
wait=tenacity.wait_fixed(1),
retry=tenacity.retry_if_exception_type(RETRY_EXCEPTIONS),
reraise=True)
def exec_command(self, cmd, encoding="utf-8", timeout=None):
if timeout:
original_timeout = self.timeout
self.timeout = timeout
try:
return super(Client, self).exec_command(cmd=cmd, encoding=encoding)
finally:
if timeout:
self.timeout = original_timeout
def execute_script(self, script, become_root=False, combine_stderr=False,
shell='sh -eux', timeout=None, **params):
"""Connect to remote machine and executes script.
Implementation note: it passes script lines to shell interpreter via
STDIN. Therefore script line number could be not available to some
script interpreters for debugging porposes.
:param script: script lines to be executed.
:param become_root: executes interpreter as root with sudo.
:param combine_stderr (bool): whenever to redirect STDERR to STDOUT so
that output from both streams are returned together. True by default.
:param shell: command line used to launch script interpreter. By
default it executes Bash with -eux options enabled. This means that
any command returning non-zero exist status or any any undefined
variable would interrupt script execution with an error and every
command executed by the script is going to be traced to STDERR.
:param timeout: time in seconds to wait before brutally aborting
script execution.
:param **params: script parameter values to be assigned at the
beginning of the script.
:returns output written by script to STDOUT.
:raises tempest.lib.exceptions.SSHTimeout: in case it fails to connect
to remote server or it fails to open a channel.
:raises tempest.lib.exceptions.SSHExecCommandFailed: in case command
script exits with non zero exit status or times out.
"""
if params:
# Append script parameters at the beginning of the script
header = ''.join(sorted(["{!s}={!s}\n".format(k, v)
for k, v in params.items()]))
script = header + '\n' + script
timeout = timeout or self.timeout
end_of_time = time.time() + timeout
output_data = b''
error_data = b''
exit_status = None
channel = self.open_session()
with channel:
# Combine STOUT and STDERR to have to handle with only one stream
channel.set_combine_stderr(combine_stderr)
# Update local environment
lang, encoding = locale.getlocale()
if not lang:
lang, encoding = locale.getdefaultlocale()
_locale = '.'.join([lang, encoding])
channel.update_environment({'LC_ALL': _locale,
'LANG': _locale})
if become_root:
shell = 'sudo ' + shell
# Spawn a Bash
channel.exec_command(shell)
end_of_script = False
lines_iterator = iter(script.splitlines())
while (not channel.exit_status_ready() and
time.time() < end_of_time):
# Drain incoming data buffers
while channel.recv_ready():
output_data += channel.recv(self.buf_size)
while channel.recv_stderr_ready():
error_data += channel.recv_stderr(self.buf_size)
if not end_of_script and channel.send_ready():
try:
line = next(lines_iterator)
except StopIteration:
# Finalize Bash script execution
channel.shutdown_write()
end_of_script = True
else:
# Send script to Bash STDIN line by line
channel.send((line + '\n').encode(encoding))
continue
time.sleep(.1)
# Get exit status and drain incoming data buffers
if channel.exit_status_ready():
exit_status = channel.recv_exit_status()
while channel.recv_ready():
output_data += channel.recv(self.buf_size)
while channel.recv_stderr_ready():
error_data += channel.recv_stderr(self.buf_size)
stdout = _buffer_to_string(output_data, encoding)
if exit_status == 0:
return stdout
stderr = _buffer_to_string(error_data, encoding)
if exit_status is None:
raise exc.SSHScriptTimeoutExpired(
command=shell, host=self.host, script=script, stderr=stderr,
stdout=stdout, timeout=timeout)
else:
raise exc.SSHScriptFailed(
command=shell, host=self.host, script=script, stderr=stderr,
stdout=stdout, exit_status=exit_status)
def get_hostname(self):
"""Retrieve the remote machine hostname"""
try:
return self.exec_command('hostname')
except exceptions.SSHExecCommandFailed:
return self.exec_command('cat /etc/hostname')
def _buffer_to_string(data_buffer, encoding):
return data_buffer.decode(encoding).replace("\r\n", "\n").replace(
"\r", "\n")