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"""Python Client for eAPI
This module provides the client for eAPI. It provides the primary functions
for building applications that work with Arista EOS eAPI-enabled nodes. The
first function is to provide a client for sending and receiving eAPI
request and response objects on a per node basis. The second function
provides a library for building API enabled data models for configuring
EOS nodes.
This library allows for creating connections to EOS eAPI enabled nodes using
the connect or connect_to function. Both functions will return an instance
of a Node object that can be used to send and receive eAPI commands. The
Node object can autoload API modules for a structured object oriented
approach to configuring the EOS node with native Python objects.
Example:
>>> import pyeapi
>>> conn = pyeapi.connect(host='10.1.1.1', transport='http')
>>> conn.execute(['show version'])
{u'jsonrpc': u'2.0', u'result': [{u'memTotal': 2028008, u'version':
u'4.14.5F', u'internalVersion': u'4.14.5F-2209869.4145F', u'serialNumber':
u'', u'systemMacAddress': u'00:0c:29:f5:d2:7d', u'bootupTimestamp':
1421765066.11, u'memFree': 213212, u'modelName': u'vEOS', u'architecture':
u'i386', u'internalBuildId': u'f590eed4-1e66-43c6-8943-cee0390fbafe',
u'hardwareRevision': u''}], u'id': u'4312565648'}
>>> node = pyeapi.connect_to('veos01')
>>> node.enable('show version')
{u'jsonrpc': u'2.0', u'result': [{u'memTotal': 2028008, u'version':
u'4.14.5F', u'internalVersion': u'4.14.5F-2209869.4145F', u'serialNumber':
u'', u'systemMacAddress': u'00:0c:29:f5:d2:7d', u'bootupTimestamp':
1421765066.11, u'memFree': 213212, u'modelName': u'vEOS', u'architecture':
u'i386', u'internalBuildId': u'f590eed4-1e66-43c6-8943-cee0390fbafe',
u'hardwareRevision': u''}], u'id': u'4312565648'}
Additionally the node object can automatically load API modules to work
with the resources in the configuration. The API autoloader supports
automatic loading of modules in pyeapi.api as well as provides the ability
to build custom API modules to be loaded from a different namespace.
Example:
>>> import pyeapi
>>> node = pyeapi.connect_to('veos01')
>>> node.api('vlans').get(1)
{'state': 'active', 'name': 'default', 'vlan_id': 1, 'trunk_groups': []}
The API autoloader loads API modules by their filename.
The following objects are provide in this module for creating clients to
interface with eAPI.
Node -- Creates an instance of a node object that represents a single EOS
device. Each EOS device to be managed should have a Node instance
Config -- A subclass of ConfigParser.SafeConfigParser that handles the
configuration file. The configuration file is an INI style file that
contains the settings for nodes used by the connect_to function.
"""
from uuid import uuid4
import os
import re
try:
# Try Python 3.x import first
# Note: SafeConfigParser is deprecated and replaced by ConfigParser
from configparser import ConfigParser as SafeConfigParser
from configparser import Error as SafeConfigParserError
except ImportError:
# Use Python 2.7 import as a fallback
from ConfigParser import SafeConfigParser
from ConfigParser import Error as SafeConfigParserError
from pyeapi.utils import load_module, make_iterable, debug
from pyeapi.eapilib import HttpEapiConnection, HttpsEapiConnection
from pyeapi.eapilib import HttpsEapiCertConnection
from pyeapi.eapilib import SocketEapiConnection, HttpLocalEapiConnection
from pyeapi.eapilib import CommandError
CONFIG_SEARCH_PATH = ['~/.eapi.conf', '/mnt/flash/eapi.conf']
TRANSPORTS = {
'socket': SocketEapiConnection,
'http_local': HttpLocalEapiConnection,
'http': HttpEapiConnection,
'https': HttpsEapiConnection,
'https_certs': HttpsEapiCertConnection
}
DEFAULT_TRANSPORT = 'https'
class Config(SafeConfigParser):
"""Conifguration instance for managing the eapi.conf file.
This class provides an instance for handling the configuration file. It
should normally need to be instantiated. A single config object is
instantiated by the module for working with the config.
Attributes:
filename (str): The full path to the loaded filename
Args:
filename(str): The full path to the filename to be loaded when the
object is instantiated.
"""
def __init__(self, filename=None):
SafeConfigParser.__init__(self)
self.filename = filename
self.tags = dict()
self.autoload()
@property
def connections(self):
"""
Returns all of the loaded connections names as a list
"""
conn = lambda x: str(x).replace('connection:', '')
return [conn(name) for name in self.sections()]
def autoload(self):
""" Loads the eapi.conf file
This method will use the module variable CONFIG_SEARCH_PATH to
attempt to locate a valid eapi.conf file if a filename is not already
configured. This method will load the first eapi.conf file it
finds and then return.
The CONFIG_SEARCH_PATH can be overridden using an environment variable
by setting EAPI_CONF.
"""
path = list(CONFIG_SEARCH_PATH)
if 'EAPI_CONF' in os.environ:
path = os.environ['EAPI_CONF']
elif self.filename:
path = self.filename
path = make_iterable(path)
for filename in path:
filename = os.path.expanduser(filename)
if os.path.exists(filename):
self.filename = filename
return self.read(filename)
self._add_default_connection()
def read(self, filename):
"""Reads the file specified by filename
This method will load the eapi.conf file specified by filename into
the instance object. It will also add the default connection localhost
if it was not defined in the eapi.conf file
Args:
filename (str): The full path to the file to load
"""
try:
SafeConfigParser.read(self, filename)
except SafeConfigParserError as exc:
# Ignore file and syslog a message on SafeConfigParser errors
msg = ("%s: parsing error in eapi conf file: %s" %
(type(exc).__name__, filename))
debug(msg)
self._add_default_connection()
for name in self.sections():
if name.startswith('connection:') and \
'host' not in dict(self.items(name)):
self.set(name, 'host', name.split(':')[1])
self.generate_tags()
def _add_default_connection(self):
"""Checks the loaded config and adds the localhost profile if needed
This method wil load the connection:localhost profile into the client
configuration if it is not already present.
"""
if not self.get_connection('localhost'):
self.add_connection('localhost', transport='socket')
def generate_tags(self):
""" Generates the tags with collection with hosts
"""
self.tags = dict()
for section in self.sections():
if self.has_option(section, 'tags'):
tags = self.get(section, 'tags')
for tag in [str(t).strip() for t in tags.split(',')]:
if tag not in self.tags:
self.tags[tag] = list()
self.tags[tag].append(section.split(':')[1])
def load(self, filename):
"""Loads the file specified by filename
This method works in conjunction with the autoload method to load the
file specified by filename.
Args:
filename (str): The full path to the file to be loaded
"""
self.filename = filename
self.reload()
def reload(self):
"""Reloades the configuration
This method will reload the configuration instance using the last
known filename. Note this method will initially clear the
configuration and reload all entries.
"""
for section in self.sections():
self.remove_section(section)
self.autoload()
def get_connection(self, name):
"""Returns the properties for a connection name
This method will return the settings for the configuration specified
by name. Note that the name argument should only be the name.
For instance, give the following eapi.conf file
.. code-block:: ini
[connection:veos01]
transport: http
The name to use to retrieve the configuration would be veos01
>>> pyeapi.client.config.get_connection('veos01')
Args:
name (str): The name of the connection to return
Returns:
A Python dictionary object of key/value pairs that represent
the node configuration. If the name provided in the argument
is not found, then None is returned.
"""
name = 'connection:{}'.format(name)
if not self.has_section(name):
return None
return dict(self.items(name))
def add_connection(self, name, **kwargs):
"""Adds a connection to the configuration
This method will add a connection to the configuration. The connection
added is only available for the lifetime of the object and is not
persisted.
Note:
If a call is made to load() or reload(), any connections added
with this method must be re-added to the config instance
Args:
name (str): The name of the connection to add to the config. The
name provided will automatically be prepended with the string
connection:
**kwargs (dict); The set of properties used to provide the node
configuration
"""
name = 'connection:{}'.format(name)
self.add_section(name)
for key, value in list(kwargs.items()):
self.set(name, key, value)
self.generate_tags()
# TODO: This is a global variable (in the module) - to review the impact on
# having a shared state for the config file.
config = Config()
def load_config(filename):
"""Function method that loads a conf file
This function will load the file specified by filename into the config
instance. Its a convenience function that calls load on the config
instance
Args:
filename (str): The full path to the filename to load
"""
return config.load(filename)
def config_for(name):
""" Function to get settings for named config
This function will return the settings for a specific connection as
specified by name. Its a convenience function that calls get_connection
on the global config instance
Args:
name (str): The name of the connection to return. The connection
name is specified as the string right of the : in the INI file
Returns:
A Python dictionary object of key/value pairs that represent the
nodes configuration settings from the config instance
"""
return config.get_connection(name)
def hosts_for_tag(tag):
""" Returns the hosts assocated with the specified tag
This function will return the hosts assoicated with the tag specified
in the argument. It will return an array of connecition names.
Args:
tag (str): The name of the tag to retrieve the list of hosts for
Returns:
list: A Python list object that includes the list of hosts assoicated
with the specified tag.
None: If the specified tag does not exist, then None is returned.
"""
return config.tags.get(tag)
def make_connection(transport, **kwargs):
""" Creates a connection instance based on the transport
This function creates the EapiConnection object based on the desired
transport. It looks up the transport class in the TRANSPORTS global
dictionary.
Args:
transport (string): The transport to use to create the instance.
**kwargs: Arbitrary keyword arguments.
Returns:
An instance of a connection object based on the transport
Raises:
TypeError: A TypeError is raised if the transport keyword is not
found in the list (keys) of available transports.
"""
if transport not in TRANSPORTS:
raise TypeError('invalid transport specified')
klass = TRANSPORTS[transport]
return klass(**kwargs)
def connect(transport=None, host='localhost', username='admin',
password='', port=None, key_file=None, cert_file=None,
ca_file=None, timeout=60, return_node=False, **kwargs):
""" Creates a connection using the supplied settings
This function will create a connection to an Arista EOS node using
the arguments. All arguments are optional with default values.
Args:
transport (str): Specifies the type of connection transport to use.
Valid values for the connection are socket, http_local, http, and
https. The default value is specified in DEFAULT_TRANSPORT
host (str): The IP addres or DNS host name of the connection device.
The default value is 'localhost'
username (str): The username to pass to the device to authenticate
the eAPI connection. The default value is 'admin'
password (str): The password to pass to the device to authenticate
the eAPI connection. The default value is ''
port (int): The TCP port of the endpoint for the eAPI connection. If
this keyword is not specified, the default value is automatically
determined by the transport type. (http=80, https=443)
key_file (str): Path to private key file for ssl validation
cert_file (str): Path to PEM formatted cert file for ssl validation
ca_file (str): Path to CA PEM formatted cert file for ssl validation
timeout (int): timeout
return_node (bool): Returns a Node object if True, otherwise
returns an EapiConnection object.
Returns:
An instance of an EapiConnection object for the specified transport.
"""
transport = transport or DEFAULT_TRANSPORT
connection = make_connection(transport, host=host, username=username,
password=password, key_file=key_file,
cert_file=cert_file, ca_file=ca_file,
port=port, timeout=timeout)
if return_node:
return Node(connection, transport=transport, host=host,
username=username, password=password, key_file=key_file,
cert_file=cert_file, ca_file=ca_file, port=port, **kwargs)
return connection
class Node(object):
"""Represents a single device for sending and receiving eAPI messages
The Node object provides an instance for communicating with Arista EOS
devices. The Node object provides easy to use methods for sending both
enable and config commands to the device using a specific transport. This
object forms the base for communicating with devices.
Attributes:
connection (EapiConnection): The connection property represents the
underlying transport used by the Node object to communicate
with the device using eAPI.
running_config (str): The running-config from the device. This
property is lazily loaded and refreshed over the life cycle of
the instance.
startup_config (str): The startup-config from the device. This
property is lazily loaded and refreshed over the life cycle of
the instance.
autorefresh (bool): If True, the running-config and startup-config are
refreshed on config events. If False, then the config properties
must be manually refreshed.
settings (dict): Provides access to the settings used to create the
Node instance.
Args:
connection (EapiConnection): An instance of EapiConnection used as the
transport for sending and receiving eAPI requests and responses.
**kwargs: An arbitrary list of keyword arguments
"""
def __init__(self, connection, **kwargs):
self._connection = connection
self._running_config = None
self._startup_config = None
self._version = None
self._version_number = None
self._model = None
self._session_name = None
self._enablepwd = kwargs.get('enablepwd')
self.autorefresh = kwargs.get('autorefresh', True)
self.settings = kwargs
def __str__(self):
return 'Node(connection=%s)' % str(self._connection)
def __repr__(self):
return 'Node(connection=%s)' % repr(self._connection)
@property
def connection(self):
return self._connection
@property
def running_config(self):
if self._running_config is not None:
return self._running_config
self._running_config = self.get_config(params='all',
as_string=True)
return self._running_config
@property
def startup_config(self):
if self._startup_config is not None:
return self._startup_config
self._startup_config = self.get_config('startup-config',
as_string=True)
return self._startup_config
@property
def version(self):
if self._version:
return self._version
self._get_version_properties()
return self._version
@property
def version_number(self):
if self._version_number:
return self._version_number
self._get_version_properties()
return self._version_number
@property
def model(self):
if self._model:
return self._model
self._get_version_properties()
return self._model
def _get_version_properties(self):
"""Parses version and model information out of 'show version' output
and uses the output to populate class properties.
"""
# Parse out version info
output = self.enable('show version')
self._version = str(output[0]['result']['version'])
match = re.match(r'[\d.\d]+', str(output[0]['result']['version']))
if match:
self._version_number = str(match.group(0))
else:
self._version_number = str(output[0]['result']['version'])
# Parse out model number
match = re.search(r'\d\d\d\d', str(output[0]['result']['modelName']))
if match:
self._model = str(match.group(0))
else:
self._model = str(output[0]['result']['modelName'])
def enable_authentication(self, password):
"""Configures the enable mode authentication password
EOS supports an additional password authentication mechanism for
sessions that want to switch to executive (or enable) mode. This
method will configure the password, if required, for entering
executive mode
Args:
password (str): The password string in clear text used to
authenticate to exec mode
"""
self._enablepwd = str(password).strip()
def config(self, commands, **kwargs):
"""Configures the node with the specified commands
This method is used to send configuration commands to the node. It
will take either a string or a list and prepend the necessary commands
to put the session into config mode.
Args:
commands (str, list): The commands to send to the node in config
mode. If the commands argument is a string it will be cast to
a list.
The list of commands will also be prepended with the
necessary commands to put the session in config mode.
**kwargs: Additional keyword arguments for expanded eAPI
functionality. Only supported eAPI params are used in building
the request
Returns:
The config method will return a list of dictionaries with the
output from each command. The function will strip the
response from any commands it prepends.
"""
if self._session_name: # If in a config session
return self._configure_session(commands, **kwargs)
return self._configure_terminal(commands, **kwargs)
def _configure_terminal(self, commands, **kwargs):
"""Configures the node with the specified commands with leading "configure terminal"
"""
commands = make_iterable(commands)
commands = list(commands)
# push the configure command onto the command stack
commands.insert(0, 'configure terminal')
response = self.run_commands(commands, **kwargs)
if self.autorefresh:
self.refresh()
# pop the configure command output off the stack
response.pop(0)
return response
def _configure_session(self, commands, **kwargs):
"""Configures the node with the specified commands with leading "configure session <session name>"
"""
if not self._session_name:
raise CommandError('Not currently in a session')
commands = make_iterable(commands)
commands = list(commands)
# push the configure command onto the command stack
commands.insert(0, 'configure session %s' % self._session_name)
response = self.run_commands(commands, **kwargs)
# pop the configure command output off the stack
response.pop(0)
return response
def section(self, regex, config='running_config'):
"""Returns a section of the config
Args:
regex (str): A valid regular expression used to select sections
of configuration to return
config (str): The configuration to return. Valid values for config
are "running_config" or "startup_config". The default value
is "running_config"
Returns:
The configuration section as a string object.
"""
if config in ['running_config', 'startup_config']:
config = getattr(self, config)
match = re.search(regex, config, re.M)
if not match:
raise TypeError('config section not found')
block_start, line_end = match.regs[0]
match = re.search(r'^[^\s]', config[line_end:], re.M)
if not match:
raise TypeError('could not find end block')
_, block_end = match.regs[0]
block_end = line_end + block_end
return config[block_start:block_end]
def enable(self, commands, encoding='json', strict=False,
send_enable=True, **kwargs):
"""Sends the array of commands to the node in enable mode
This method will send the commands to the node and evaluate
the results. If a command fails due to an encoding error,
then the command set will be re-issued individual with text
encoding.
Args:
commands (list): The list of commands to send to the node
encoding (str): The requested encoding of the command output.
Valid values for encoding are JSON or text
strict (bool): If False, this method will attempt to run a
command with text encoding if JSON encoding fails
send_enable (bool): If True the enable command will be
prepended to the command list automatically.
**kwargs: Additional keyword arguments for expanded eAPI
functionality. Only supported eAPI params are used in building
the request
Returns:
A dict object that includes the response for each command along
with the encoding
Raises:
TypeError:
This method does not support sending configure
commands and will raise a TypeError if configuration commands
are found in the list of commands provided
This method will also raise a TypeError if the specified
encoding is not one of 'json' or 'text'
CommandError: This method will raise a CommandError if any one
of the commands fails.
"""
commands = make_iterable(commands)
if 'configure' in commands:
raise TypeError('config mode commands not supported')
results = list()
# IMPORTANT: There are two keys (response, result) that both
# return the same value. 'response' was originally placed
# there in error and both are now present to avoid breaking
# existing scripts. 'response' will be removed in a future release.
if strict:
responses = self.run_commands(commands, encoding, send_enable,
**kwargs)
for index, response in enumerate(responses):
results.append(dict(command=commands[index],
result=response,
response=response,
encoding=encoding))
else:
for command in commands:
try:
resp = self.run_commands(command, encoding, send_enable,
**kwargs)
results.append(dict(command=command,
result=resp[0],
encoding=encoding))
except CommandError as exc:
if exc.error_code == 1003:
resp = self.run_commands(command, 'text', send_enable,
**kwargs)
results.append(dict(command=command,
result=resp[0],
encoding='text'))
else:
raise
return results
def run_commands(self, commands, encoding='json', send_enable=True,
**kwargs):
"""Sends the commands over the transport to the device
This method sends the commands to the device using the nodes
transport. This is a lower layer function that shouldn't normally
need to be used, preferring instead to use config() or enable().
Args:
commands (list): The ordered list of commands to send to the
device using the transport
encoding (str): The encoding method to use for the request and
excpected response.
send_enable (bool): If True the enable command will be
prepended to the command list automatically.
**kwargs: Additional keyword arguments for expanded eAPI
functionality. Only supported eAPI params are used in building
the request
Returns:
This method will return the raw response from the connection
which is a Python dictionary object.
"""
commands = make_iterable(commands)
# Some commands are multiline commands. These are banner commands and
# SSL commands. So with this two lines we
# can support those by passing commands by doing:
# banner login MULTILINE: This is my banner.\nAnd I even support
# multiple lines.
# Why this? To be able to read a configuration from a file, split it
# into lines and pass it as it is
# to pyeapi without caring about multiline commands.
commands = [{'cmd': c.split('MULTILINE:')[0],
'input': '%s\n' % (c.split('MULTILINE:')[1].strip())}
if 'MULTILINE:' in c else c for c in commands]
if send_enable:
if self._enablepwd:
commands.insert(0, {'cmd': 'enable', 'input': self._enablepwd})
else:
commands.insert(0, 'enable')
response = self._connection.execute(commands, encoding, **kwargs)
# pop enable command from the response only if we sent enable
if send_enable:
response['result'].pop(0)
return response['result']
def api(self, name, namespace='pyeapi.api'):
"""Loads the specified api module
This method is the API autoload mechanism that will load the API
module specified by the name argument. The API module will be loaded
and look first for an initialize() function and secondly for an
instance() function. In both cases, the node object is passed to
the module.
Args:
name (str): The name of the module to load. The name should be
the name of the python file to import
namespace (str): The namespace to use to load the module. The
default value is 'pyeapi.api'
Returns:
The API module loaded with the node instance.
"""
module = load_module('{}.{}'.format(namespace, name))
if hasattr(module, 'initialize'):
module.initialize(self)
if hasattr(module, 'instance'):
return module.instance(self)
return module
def get_config(self, config='running-config', params=None,
as_string=False):
""" Retreives the config from the node
This method will retrieve the config from the node as either a string
or a list object. The config to retrieve can be specified as either
the startup-config or the running-config.
Args:
config (str): Specifies to return either the nodes startup-config
or running-config. The default value is the running-config
params (str): A string of keywords to append to the command for
retrieving the config.
as_string (boo): Flag that determines the response. If True, then
the configuration is returned as a raw string. If False, then
the configuration is returned as a list. The default value is
False
Returns:
This method will return either a string or a list depending on the
states of the as_string keyword argument.
Raises:
TypeError: If the specified config is not one of either
'running-config' or 'startup-config'
"""
if config not in ['startup-config', 'running-config']:
raise TypeError('invalid config name specified')
command = 'show %s' % config
if params:
command += ' %s' % params
result = self.run_commands(command, 'text')
if as_string:
return str(result[0]['output']).strip()
return str(result[0]['output']).split('\n')
def refresh(self):
"""Refreshes the instance config properties
This method will refresh the public running_config and startup_config
properites. Since the properties are lazily loaded, this method will
clear the current internal instance variables. One the next call the
instance variables will be repopulated with the current config
"""
self._running_config = None
self._startup_config = None
def configure_session(self):
"""Enter a config session
"""
self._session_name = self._session_name or uuid4()
def diff(self):
"""Returns session-config diffs in text encoding
Note: "show session-config diffs" doesn't support json encoding
"""
response = self._configure_session(['show session-config diffs'], encoding='text')
return response[0]['output']
def commit(self):
"""Commits the current config session
"""
return self._configure_and_exit_session(['commit'])
def abort(self):
"""Aborts the current config session
"""
return self._configure_session(['abort'])
def _configure_and_exit_session(self, commands, **kwargs):
response = self._configure_session(commands, **kwargs)
if self.autorefresh:
self.refresh()
# Exit the current config session
self._session_name = None
return response
def connect_to(name):
"""Creates a node instance based on an entry from the config
This function will retrieve the settings for the specified connection
from the config and return a Node instance. The configuration must
be loaded prior to calling this function.
Args:
name (str): The name of the connection to load from the config. The
name argument should be the connection name (everything right of
the colon from the INI file)
Returns:
This function will return an instance of Node with the settings
from the config instance.
Raises:
AttributeError: raised if the specified configuration name is not
found in the loaded configuration
"""
kwargs = config_for(name)
if not kwargs:
raise AttributeError('connection profile not found in config')
node = connect(return_node=True, **kwargs)
return node
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