Programmability Configuration Guide, Cisco IOS XE Everest 16.5.1a (Catalyst 9500 Switches)

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to https://cfnng.cisco.com/. An account on Cisco.com is not required.

About Python

The Cisco IOS XE devices support Python Version 2.7 in both interactive and non-interactive (script) modes within the Guest Shell. The Python scripting capability gives programmatic access to a device's CLI to perform various tasks and Zero Touch Provisioning or Embedded Event Manager (EEM) actions.

Python Scripts Overview

Python run in a virtualized Linux-based environment, Guest Shell. For more information, see the Guest Shell chapter. Cisco provides a Python module that allows user’s Python scripts to run IOS CLI commands on the host device.

Interactive Python Prompt

When you execute the guestshell run python command on a device, the interactive Python prompt is opened inside the Guest Shell. The Python interactive mode allows users to execute Python functions from the Cisco Python CLI module to configure the device.

The following example shows how to enable the interactive Python prompt:


Device# guestshell run python

Python 2.7.5 (default, Jun 17 2014, 18:11:42) 
[GCC 4.8.2 20140120 (Red Hat 4.8.2-16)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>

Device#

Python Script

Python scripts can run in non-interactive mode by providing the Python script name as an argument in the Python command. Python scripts must be accessible from within the Guest Shell. To access Python scripts from the Guest Shell, save the scripts in bootflash/flash that is mounted within the Guest Shell.

The following sample Python script uses different CLI functions to configure and print show commands:

Device# more flash:sample_script.py


import sys
import cli

intf= sys.argv[1:]
intf = ''.join(intf[0])

print "\n\n *** Configuring interface %s with 'configurep' function  *** \n\n" %intf
cli.configurep(["interface loopback55","ip address 10.55.55.55 255.255.255.0","no shut","end"])

print "\n\n *** Configuring interface %s with 'configure' function  *** \n\n"
cmd='interface %s,logging event link-status ,end' % intf
cli.configure(cmd.split(','))

print "\n\n *** Printing show cmd with 'executep' function  *** \n\n"    
cli.executep('show ip interface brief')

print "\n\n *** Printing show cmd with 'execute' function  *** \n\n" 
output= cli.execute('show run interface %s' %intf)
print (output)

print "\n\n *** Configuring interface %s with 'cli' function  *** \n\n"
cli.cli('config terminal; interface %s; spanning-tree portfast edge default' %intf)

print "\n\n *** Printing show cmd with 'clip' function  *** \n\n"
cli.clip('show run interface %s' %intf)


To run a Python script from the Guest Shell, execute the guestshell run python /flash/script.py command
at the device prompt.
The following example shows how to run a Python script from the Guest Shell:

The following example shows how to run a Python script from the Guest Shell:


Device# guestshell run python /flash/sample_script.py loop55 

 *** Configuring interface loop55 with 'configurep' function  *** 

Line 1 SUCCESS: interface loopback55
Line 2 SUCCESS: ip address 10.55.55.55 255.255.255.0
Line 3 SUCCESS: no shut
Line 4 SUCCESS: end

 *** Configuring interface %s with 'configure' function  *** 


 *** Printing show cmd with 'executep' function  *** 

Interface              IP-Address      OK? Method Status                Protocol
Vlan1                  unassigned      YES NVRAM  administratively down down    
GigabitEthernet0/0     192.0.2.1       YES NVRAM  up                    up      
GigabitEthernet1/0/1   unassigned      YES unset  down                  down    
GigabitEthernet1/0/2   unassigned      YES unset  down                  down    
GigabitEthernet1/0/3   unassigned      YES unset  down                  down    
   	:
         :
         :
Te1/1/4                unassigned      YES unset  down                  down    
Loopback55             10.55.55.55     YES TFTP   up                    up      
Loopback66             unassigned      YES manual up                    up      


 *** Printing show cmd with 'execute' function  *** 

Building configuration...
Current configuration : 93 bytes
!
interface Loopback55
 ip address 10.55.55.55 255.255.255.0
 logging event link-status
end

 *** Configuring interface %s with 'cli' function  *** 

 *** Printing show cmd with 'clip' function  *** 

Building configuration...
Current configuration : 93 bytes
!
interface Loopback55
 ip address 10.55.55.55 255.255.255.0
 logging event link-status
end

Supported Python Versions

Guest Shell is pre-installed with Python Version 2.7. Guest Shell is a virtualized Linux-based environment, designed to run custom Linux applications, including Python applications for automated control and management of Cisco devices. Platforms with Montavista CGE7 support Python Version 2.7.11, and platforms with CentOS 7 support Python Version 2.7.5.

The following table provides information about Python versions and the supported platforms:

Table 1. Python Version Support
Python Version	Platform

Platforms with CentOS 7 support the installation of Redhat Package Manager (RPM) from the open source repository.

Updating the Cisco CLI Python Module

The Cisco CLI Python module and EEM module are pre-installed on devices. However, when you update the Python version by using either Yum or prepackaged binaries, the Cisco-provided CLI module must also be updated.

Note

When you update to Python Version 3 on a device that already has Python Version 2, both versions of Python exist on the device. Use one of the following IOS commands to run Python:

The guestshell run python2 command enables Python Version 2.
The guestshell run python3 command enables Python Version 3.
The guestshell run python command enables Python Version 2.

Use one of the following methods to update the Python version:

Standalone tarball installation
PIP install for the CLI module

Additional References for the CLI Python Module

Related Topic	Document Title
Guest Shell
EEM Python Module

Technical Assistance


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Feature Information for the CLI Python Module

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 2. Feature Information for the CLI Python Module
Feature Name	Release	Feature Information
CLI Python Module		Python programmabilty provides a Python module that allows users to interact with IOS using CLIs.

Bias-Free Language

Book Title

Programmability Configuration Guide, Cisco IOS XE Everest 16.5.1a (Catalyst 9500 Switches)

Chapter Title

CLI Python Module

Results

Chapter: CLI Python Module