NetLib

Netlib is an attempt at re-writing 'pyRouterLib'. The goal is to create a library that is much more efficient and easier to use to establish SSH, Telnet, and SNMP connection to network devices, such as routers and switches.

Install

To be able to use the snmp utilities, you will need the development packages for net-snmp installed.

Debian-Based Linux:

sudo apt-get install python-pip python-dev python3-dev libsnmp-dev libffi-dev snmp-mibs-downloader

Redhat-Based Linux:

sudo yum -y install net-snmp-devel

Other than that, it's just a matter of installing the Python library.

git clone https://github.com/jtdub/netlib.git
cd netlib

# For Python2 Support:
sudo python setup.py install

# For Python3 Support:
sudo python3 setup.py install

Access via Telnet and SSH

Currently, the SSH and Telnet modules have been created. Both modules have a very similar API structure, with the biggest difference between the two are how connections are established to network devices.

To use either the SSH or Telnet module, you need to import the library into your script:

from netlib.conn_type import SSH
from netlib.conn_type import Telnet

From there, you define your connection parameters:

telnet = Telnet('somerouter', 'username', 'password')
ssh = SSH('somerouter', 'username', 'password')

Once the basic parameters have been set, you establish a connection to the device.

telnet.connect()
ssh.connect()

Once you are connected, you are free to send commands to you network device. If you intend to iterate through output that is long, then you can disable paging on the output.

telnet.disable_paging()
ssh.disable_paging()

telnet.command('show version')
ssh.command('show version')

If you need to enter a privileged mode, you can use the set_enable api.

telnet.set_enable('supersecretpassword')
ssh.set_enable('supersecretpassword')

When you've completed your task on the device, you can close your connections.

telnet.close()
ssh.close()

At this point, those are the features that both libraries share. As the telnet library and ssh library vary on how they parse data, there is a need for extra functionality on the ssh library. Here is the API functionality that is specific to the ssh library:

ssh.clear_buffer()

The SSH library stores output into a buffer. Sometimes this buffer can present results that aren't expected. Clearing the buffer should mitigate the unexpected results.

SNMP

SNMP functionality is still very experimental. It currently only supports SNMP version 2. Version 3 support will hopefully come soon.

To use the SNMP functionality, you will need to import the module into your python script.

>>> from netlib.conn_type import SNMPv2

From there, enter your polling parameters.

>>> s = SNMPv2(device_name='somerouter', snmp_community='somecommunity', oid_name='sysDescr.0')

Then you poll the device.

>>> s.get()
u'Cisco IOS Software, C181X Software (C181X-ADVENTERPRISEK9-M), Version 15.1(4)M8, RELEASE SOFTWARE (fc2)\r\nTechnical Support: http://www.cisco.com/techsupport\r\nCopyright (c) 1986-2014 by Cisco Systems, Inc.\r\nCompiled Fri 07-Mar-14 07:42 by prod_rel_team'

Again, the functionality of the SNMP module is still very limited. I hope to work on it soon and create a more robust functionality for SNMP.

User Credentials

When working with a large number of devices, it's inconvenient to have to type your credentials in a large number of times and storing your credentials directly into a script can be insecure. Therefore, I created a library that allows you to store them, securely utilizing the 'keyring' python library. 'keyring' utilizes your operating systems native method for storing passwords. For example, in MacOS X, the Keychain utility is utilized.

The past methods of password storage, simple_creds and simple_yaml have been depricated and removed from netlib.

Utilizing the keyring is simple. Import the module:

>>> from netlib.user_keyring import KeyRing

Asign it to a variable, calling your username:

>>> user = KeyRing(username='jtdub')

If there are no credentials for the keyring, the get_creds() method will call the set_creds() method:

>>> user.get_creds()
No credentials keyring exist. Creating new credentials.
Enter your user password: 
Confirm your user password: 
Enter your enable password: 
Confirm your enable password: 

Otherwise, the creds will be pulled from the keyring:

>>> user.get_creds()
{'username': 'jtdub', 'enable': u'enablepass', 'password': u'testpass'}

The set_creds() method can be called directly. It will over-write existing creds if they exist:

>>> user.set_creds()
Enter your user password: 
Confirm your user password: 
Enter your enable password: 
Confirm your enable password: 
>>> user.get_creds()
{'username': 'jtdub', 'enable': u'newenable', 'password': u'newpass'}

Of course, the keyring can be deleted all together utilizing the del_creds() method:

>>> user.del_creds()
Enter your user password: 
Deleting keyring credentials for jtdub
>>>