"""Provides a factory method to create a host object."""
import logging
from contextlib import closing
from autotest_lib.client.bin import local_host
from autotest_lib.client.common_lib import error, global_config
from autotest_lib.server import utils as server_utils
from autotest_lib.server.hosts import cros_host, ssh_host
from autotest_lib.server.hosts import moblab_host, sonic_host
from autotest_lib.server.hosts import adb_host, testbed
SSH_ENGINE = global_config.global_config.get_config_value('AUTOSERV',
'ssh_engine',
type=str)
# Default ssh options used in creating a host.
DEFAULT_SSH_USER = 'root'
DEFAULT_SSH_PASS = ''
DEFAULT_SSH_PORT = 22
DEFAULT_SSH_VERBOSITY = ''
DEFAULT_SSH_OPTIONS = ''
# for tracking which hostnames have already had job_start called
_started_hostnames = set()
# A list of all the possible host types, ordered according to frequency of
# host types in the lab, so the more common hosts don't incur a repeated ssh
# overhead in checking for less common host types.
host_types = [cros_host.CrosHost, moblab_host.MoblabHost, sonic_host.SonicHost,
adb_host.ADBHost,]
OS_HOST_DICT = {'cros' : cros_host.CrosHost,
'android': adb_host.ADBHost}
def _get_host_arguments():
"""Returns parameters needed to ssh into a host.
There are currently 2 use cases for creating a host.
1. Through the server_job, in which case the server_job injects
the appropriate ssh parameters into our name space and they
are available as the variables ssh_user, ssh_pass etc.
2. Directly through factory.create_host, in which case we use
the same defaults as used in the server job to create a host.
@returns: A tuple of parameters needed to create an ssh connection, ordered
as: ssh_user, ssh_pass, ssh_port, ssh_verbosity, ssh_options.
"""
g = globals()
return (g.get('ssh_user', DEFAULT_SSH_USER),
g.get('ssh_pass', DEFAULT_SSH_PASS),
g.get('ssh_port', DEFAULT_SSH_PORT),
g.get('ssh_verbosity_flag', DEFAULT_SSH_VERBOSITY),
g.get('ssh_options', DEFAULT_SSH_OPTIONS))
def _detect_host(connectivity_class, hostname, **args):
"""Detect host type.
Goes through all the possible host classes, calling check_host with a
basic host object. Currently this is an ssh host, but theoretically it
can be any host object that the check_host method of appropriate host
type knows to use.
@param connectivity_class: connectivity class to use to talk to the host
(ParamikoHost or SSHHost)
@param hostname: A string representing the host name of the device.
@param args: Args that will be passed to the constructor of
the host class.
@returns: Class type of the first host class that returns True to the
check_host method.
"""
# TODO crbug.com/302026 (sbasi) - adjust this pathway for ADBHost in
# the future should a host require verify/repair.
with closing(connectivity_class(hostname, **args)) as host:
for host_module in host_types:
if host_module.check_host(host, timeout=10):
return host_module
logging.warning('Unable to apply conventional host detection methods, '
'defaulting to chromeos host.')
return cros_host.CrosHost
def _choose_connectivity_class(hostname, ssh_port):
"""Choose a connectivity class for this hostname.
@param hostname: hostname that we need a connectivity class for.
@param ssh_port: SSH port to connect to the host.
@returns a connectivity host class.
"""
if (hostname == 'localhost' and ssh_port == DEFAULT_SSH_PORT):
return local_host.LocalHost
# by default assume we're using SSH support
elif SSH_ENGINE == 'paramiko':
# Not all systems have paramiko installed so only import paramiko host
# if the global_config settings call for it.
from autotest_lib.server.hosts import paramiko_host
return paramiko_host.ParamikoHost
elif SSH_ENGINE == 'raw_ssh':
return ssh_host.SSHHost
else:
raise error.AutoServError("Unknown SSH engine %s. Please verify the "
"value of the configuration key 'ssh_engine' "
"on autotest's global_config.ini file." %
SSH_ENGINE)
# TODO(kevcheng): Update the creation method so it's not a research project
# determining the class inheritance model.
def create_host(machine, host_class=None, connectivity_class=None, **args):
"""Create a host object.
This method mixes host classes that are needed into a new subclass
and creates a instance of the new class.
@param machine: A dict representing the device under test or a String
representing the DUT hostname (for legacy caller support).
If it is a machine dict, the 'hostname' key is required.
Optional 'host_attributes' key will pipe in host_attributes
from the autoserv runtime or the AFE.
@param host_class: Host class to use, if None, will attempt to detect
the correct class.
@param connectivity_class: Connectivity class to use, if None will decide
based off of hostname and config settings.
@param args: Args that will be passed to the constructor of
the new host class.
@returns: A host object which is an instance of the newly created
host class.
"""
hostname, host_attributes = server_utils.get_host_info_from_machine(
machine)
args['host_attributes'] = host_attributes
ssh_user, ssh_pass, ssh_port, ssh_verbosity_flag, ssh_options = \
_get_host_arguments()
hostname, args['user'], args['password'], ssh_port = \
server_utils.parse_machine(hostname, ssh_user, ssh_pass, ssh_port)
args['ssh_verbosity_flag'] = ssh_verbosity_flag
args['ssh_options'] = ssh_options
args['port'] = ssh_port
if not connectivity_class:
connectivity_class = _choose_connectivity_class(hostname, ssh_port)
host_attributes = args.get('host_attributes', {})
host_class = host_class or OS_HOST_DICT.get(host_attributes.get('os_type'))
if host_class:
classes = [host_class, connectivity_class]
else:
classes = [_detect_host(connectivity_class, hostname, **args),
connectivity_class]
# create a custom host class for this machine and return an instance of it
host_class = type("%s_host" % hostname, tuple(classes), {})
host_instance = host_class(hostname, **args)
# call job_start if this is the first time this host is being used
if hostname not in _started_hostnames:
host_instance.job_start()
_started_hostnames.add(hostname)
return host_instance
def create_testbed(machine, **kwargs):
"""Create the testbed object.
@param machine: A dict representing the test bed under test or a String
representing the testbed hostname (for legacy caller
support).
If it is a machine dict, the 'hostname' key is required.
Optional 'host_attributes' key will pipe in host_attributes
from the autoserv runtime or the AFE.
@param kwargs: Keyword args to pass to the testbed initialization.
@returns: The testbed object with all associated host objects instantiated.
"""
hostname, host_attributes = server_utils.get_host_info_from_machine(
machine)
kwargs['host_attributes'] = host_attributes
return testbed.TestBed(hostname, **kwargs)
def create_target_machine(machine, **kwargs):
"""Create the target machine which could be a testbed or a *Host.
@param machine: A dict representing the test bed under test or a String
representing the testbed hostname (for legacy caller
support).
If it is a machine dict, the 'hostname' key is required.
Optional 'host_attributes' key will pipe in host_attributes
from the autoserv runtime or the AFE.
@param kwargs: Keyword args to pass to the testbed initialization.
@returns: The target machine to be used for verify/repair.
"""
# TODO(kevcheng): We'll want to have a smarter way of figuring out which
# host to create (checking host labels).
if server_utils.machine_is_testbed(machine):
return create_testbed(machine, **kwargs)
return create_host(machine, **kwargs)