#
# Copyright (c) 2014, Arista Networks, Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# Neither the name of Arista Networks nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ARISTA NETWORKS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
# IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
import os
import sys
import importlib
import inspect
import logging
import logging.handlers
from collections.abc import Iterable
from itertools import tee, zip_longest
_LOGGER = logging.getLogger(__name__)
_LOGGER.setLevel(logging.DEBUG)
# Create a handler to log messages to syslog
if sys.platform == "darwin":
_syslog_handler = logging.handlers.SysLogHandler(address='/var/run/syslog')
else:
_syslog_handler = logging.handlers.SysLogHandler()
_LOGGER.addHandler(_syslog_handler)
# Create a handler to log messages to stderr
_stderr_formatter = logging.Formatter('\n\n**** LOG NOTE ****\n%(message)s\n')
_stderr_handler = logging.StreamHandler()
_stderr_handler.setFormatter(_stderr_formatter)
_LOGGER.addHandler(_stderr_handler)
[docs]
def import_module(name):
""" Imports a module into the current runtime environment
This function emulates the Python import system that allows for
importing full path modules. It will break down the module and
import each part (or skip if it is already loaded in cache).
Args:
name (str): The name of the module to import. This should be
the full path of the module
Returns:
The module that was imported
"""
if name in sys.modules:
# Be sure not to reload a previously loaded module
mod = sys.modules[name]
else:
mod = importlib.import_module(name)
return mod
[docs]
def load_module(name):
""" Attempts to load a module into the current environment
This function will load a module specified by name. The module
name is first checked to see if it is already loaded and will return
the module if it is. If the module hasn't been previously loaded
it will attempt to import it
Args:
name (str): Specifies the full name of the module. For instance
pyeapi.api.vlans
Returns:
The module that has been imported or retrieved from the sys modules
"""
try:
mod = None
mod = sys.modules[name]
except KeyError:
mod = import_module(name)
finally:
if not mod:
raise ImportError('unable to import module %s' % name)
return mod
[docs]
class ProxyCall(object):
def __init__(self, proxy, method):
self.proxy = proxy
self.method = method
def __call__(self, *args, **kwargs):
return self.proxy(self.method, *args, **kwargs)
[docs]
def islocalconnection():
""" Checks if running locally on EOS device or remotely
This function will return a boolean indicating if the current
execution environment is running locally on an EOS device (True) or
running remotely and communicating over HTTP/S (False)
Returns:
A boolean value that indicates whether or not the current
thread is local or remote
"""
return os.path.exists('/etc/Eos-release')
[docs]
def debug(text):
"""Log a message to syslog and stderr
Args:
text (str): The string object to print
"""
frame = inspect.currentframe().f_back
module = frame.f_globals['__name__']
func = frame.f_code.co_name
msg = "%s.%s: %s" % (module, func, text)
_LOGGER.debug(msg)
[docs]
def make_iterable(value):
"""Converts the supplied value to a list object
This function will inspect the supplied value and return an
iterable in the form of a list.
Args:
value (object): A valid Python object
Returns:
An iterable object of type list
"""
if isinstance(value, str) or isinstance(
value, dict) or isinstance(value, CliVariants):
value = [value]
if not isinstance(value, Iterable):
raise TypeError('value must be an iterable object')
return value
[docs]
def lookahead(it):
it1, it2 = tee(iter(it))
next(it2)
return zip_longest(it1, it2)
[docs]
def expand_range(arg, value_delimiter=',', range_delimiter='-'):
"""
Expands a delimited string of ranged integers into a list of strings
:param arg: The string range to expand
:param value_delimiter: The delimiter that separates values
:param range_delimiter: The delimiter that signifies a range of values
:return: An array of expanded string values
:rtype: list
"""
values = list()
expanded = arg.split(value_delimiter)
for item in expanded:
if range_delimiter in item:
start, end = item.split(range_delimiter)
_expand = range(int(start), int(end) + 1)
values.extend([str(x) for x in _expand])
else:
values.extend([item])
return [str(x) for x in values]
[docs]
def collapse_range(arg, value_delimiter=',', range_delimiter='-'):
"""
Collapses a list of values into a range set
:param arg: The list of values to collapse
:param value_delimiter: The delimiter that separates values
:param range_delimiter: The delimiter that separates a value range
:return: An array of collapsed string values
:rtype: list
"""
values = list()
expanded = arg.split(value_delimiter)
range_start = None
for v1, v2 in lookahead(expanded):
if v2:
v1 = int(v1)
v2 = int(v2)
if (v1 + 1) == v2:
if not range_start:
range_start = v1
elif range_start:
item = '{}{}{}'.format(range_start, range_delimiter, v1)
values.extend([item])
range_start = None
else:
values.extend([v1])
elif range_start:
item = '{}{}{}'.format(range_start, range_delimiter, v1)
values.extend([item])
range_start = None
else:
values.extend([v1])
return [str(x) for x in values]
[docs]
class CliVariants:
"""
Provides an interface for cli variants (typically to handle a transition
period for a deprecated cli)
Instance must be initialized either with 2 or more str variants:
``CliVariants( 'new cli', 'legacy cli' )``,
or with 2 or more sequences of cli (or a mix of list and str types), e.g.:
``CliVariants( ['new cli1', 'new cli2'], 'alt cli3', 'legacy cli4' )``
"""
[docs]
@staticmethod
def expand( cmds ):
""" Expands cmds argument into a list of all CLI variants
The method returns a list of all full variant combinations present
in the the cmds arguement
Args:
cmds (list): a list made of str and CliVariants types
Returns:
expanded list, e.g.:
expand( 'x', CliVariants( 'a', 'b'), 'y' )
will return: [ ['x', 'a', 'y'], ['x', 'b', 'y'] ]
"""
assert isinstance(cmds, list), 'argument cmds must be list type'
if not cmds:
return [ [] ]
head = cmds[0]
tail = cmds[1:]
if isinstance( head, CliVariants ):
return [ v + e for v in head.variants
for e in CliVariants.expand( tail ) ]
else:
return [ [head] + e for e in CliVariants.expand(tail) ]
def __init__(self, *cli):
assert len( cli ) >= 2, 'must be initialized with 2 or more arguments'
self.variants = [ v if not isinstance(v,
str) and isinstance(v, Iterable) else [v] for v in cli ]
def _interpolate_docstr( *tkns ):
"""Docstring decorator.
SYNOPSIS:
MIN_MTU=68
MAX_MTU=65535
@_interpolate_docstr( 'MIN_MTU', 'MAX_MTU' )
def mtu_check( val ):
"check mtu against its min value (MIN_MTU) and max value (MAX_MTU)"
...
print( mtu_check.__doc__ )
check mtu against its min value (68) and max value (65535)
"""
def docstr_decorator( user_fn ):
"""update user_fn_wrapper doc string with the interpolated user_fn's
"""
def user_fn_wrapper( *args, **kwargs ):
return user_fn( *args, **kwargs )
module = sys.modules[ user_fn.__module__ ]
docstr = user_fn.__doc__
for tkn in tkns:
sval = str( getattr(module, tkn) )
docstr = docstr.replace( tkn, sval )
user_fn_wrapper.__doc__ = docstr
return user_fn_wrapper
return docstr_decorator