Arista eAPI Python Library

The Python library for Arista's eAPI command API implementation provides a client API work using eAPI and communicating with EOS nodes. The Python library can be used to communicate with EOS either locally (on-box) or remotely (off-box). It uses a standard INI-style configuration file to specify one or more nodes and connection properites.

The pyeapi library also provides an API layer for building native Python objects to interact with the destination nodes. The API layer is a convienent implementation for working with the EOS configuration and is extensible for developing custom implemenations.

This library is freely provided to the open source community for building robust applications using Arista EOS. Support is provided as best effort through Github issues.

Requirements

• Arista EOS 4.12 or later
• Arista eAPI enabled for at least one transport (see Official EOS Config Guide at arista.com for details)
• Python 2.7 / 3.4+ (Python 3 support is work in progress)

Getting Started

In order to use pyeapi, the EOS command API must be enabled using management api http-commands configuration mode. This library supports eAPI calls over both HTTP and UNIX Domain Sockets. Once the command API is enabled on the destination node, create a configuration file with the node properities.

Note: The default search path for the conf file is ~/.eapi.conf followed by /mnt/flash/eapi.conf. This can be overridden by setting EAPI_CONF=<path file conf file> in your environment.

Example eapi.conf File

Below is an example of an eAPI conf file. The conf file can contain more than one node. Each node section must be prefaced by connection:<name> where <name> is the name of the connection.

The following configuration options are available for defining node entries:

• host - The IP address or FQDN of the remote device. If the host parameter is omitted then the connection name is used
• username - The eAPI username to use for authentication (only required for http or https connections)
• password - The eAPI password to use for authentication (only required for http or https connections)
• enablepwd - The enable mode password if required by the destination node
• transport - Configures the type of transport connection to use. The default value is https. Valid values are:
  • socket (available in EOS 4.14.5 or later)
  • http_local (available in EOS 4.14.5 or later)
  • http
  • https
• port - Configures the port to use for the eAPI connection. A default port is used if this parameter is absent, based on the transport setting using the following values:
  • transport: http, default port: 80
  • transport: https, deafult port: 443
  • transport: https_local, default port: 8080
  • transport: socket, default port: n/a

Note: See the EOS User Manual found at arista.com for more details on configuring eAPI values.

All configuration values are optional.

[connection:veos01]
username: eapi
password: password
transport: http

[connection:veos02]
transport: http

[connection:veos03]
transport: socket

[connection:veos04]
host: 172.16.10.1
username: eapi
password: password
enablepwd: itsasecret
port: 1234
transport: https

[connection:localhost]
transport: http_local

The above example shows different ways to define EOS node connections. All configuration options will attempt to use default values if not explicitly defined. If the host parameter is not set for a given entry, then the connection name will be used as the host address.

Configuring [connection:localhost]

The pyeapi library automatically installs a single default configuration entry for connecting to localhost host using a transport of sockets. If using the pyeapi library locally on an EOS node, simply enable the command API to use sockets and no further configuration is needed for pyeapi to function. If you specify an entry in a conf file with the name [connection:localhost], the values in the conf file will overwrite the default.

Using pyeapi

The Python client for eAPI was designed to be easy to use and implement for writing tools and applications that interface with the Arista EOS management plane.

Creating a connection and sending commands

Once EOS is configured properly and the config file created, getting started with a connection to EOS is simple. Below demonstrates a basic connection using pyeapi. For more examples, please see the examples folder.

# start by importing the library
import pyeapi

# create a node object by specifying the node to work with
node = pyeapi.connect_to('veos01')

# send one or more commands to the node
node.enable('show hostname')
[{'command': 'show hostname', 'result': {u'hostname': u'veos01', u'fqdn':
u'veos01.arista.com'}, 'encoding': 'json'}]

# use the config method to send configuration commands
node.config('hostname veos01')
[{}]

# multiple commands can be sent by using a list (works for both enable or
config)
node.config(['interface Ethernet1', 'description foo'])
[{}, {}]

# return the running or startup configuration from the node (output omitted for
brevity)
node.running_config

node.startup_config

Using the API

The pyeapi library provides both a client for send and receiving commands over eAPI as well as an API for working directly with EOS resources. The API is designed to be easy and straightforward to use yet also extensible. Below is an example of working with the vlans API

# create a connection to the node
import pyeapi
node = pyeapi.connect_to('veos01')

# get the instance of the API (in this case vlans)
vlans = node.api('vlans')

# return all vlans from the node
vlans.getall()
{'1': {'state': 'active', 'name': 'default', 'vlan_id': 1, 'trunk_groups': []},
'10': {'state': 'active', 'name': 'VLAN0010', 'vlan_id': 10, 'trunk_groups':
[]}}

# return a specific vlan from the node
vlans.get(1)
{'state': 'active', 'name': 'default', 'vlan_id': 1, 'trunk_groups': []}

# add a new vlan to the node
vlans.create(100)
True

# set the new vlan name
vlans.set_name(100, 'foo')
True

All API implementations developed by Arista EOS+ CS are found in the pyeapi/api folder. See the examples folder for additional examples.

Installation

The source code for pyeapi is provided on Github at http://github.com/arista-eosplus/pyeapi. All current development is done in the develop branch. Stable released versions are tagged in the master branch and uploaded to PyPi.

• To install the latest stable version of pyeapi, simply run pip install pyeapi (or pip install --upgrade pyeapi)
• To install the latest development version from Github, simply clone the develop branch and run python setup.py install

Testing

The pyeapi library provides both unit tests and system tests. The unit tests can be run without an EOS node. To run the system tests, you will need to update the dut.conf file found in test/fixtures.

• To run the unit tests, simply run make unittest from the root of the pyeapi source folder
• To run the system tests, simply run make systest from the root of the pyeapi source fodler
• To run all tests, use make tests from the root of the pyeapi source folder

Contributing

Contributing pull requests are gladly welcomed for this repository. Please note that all contributions that modify the library behavior require corresponding test cases otherwise the pull request will be rejected.

License

Copyright (c) 2014, Arista Networks EOS+ 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 the Arista 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 THE COPYRIGHT HOLDER OR CONTRIBUTORS 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.