The Role of Python in Network Automation: Practical Scripts for Everyday Tasks

Network engineers are increasingly turning to automation to streamline repetitive tasks and improve overall efficiency. At the heart of this transformation is Python, a versatile programming language that has become a cornerstone for network automation. In this blog, we'll explore the role Python plays in automating network tasks, highlight essential libraries, and share practical scripts to help you reduce manual effort and focus on strategic initiatives.

Why Python for Network Automation?

Python's simplicity and vast ecosystem of libraries make it ideal for network automation. Its compatibility with APIs, ease of learning, and extensive community support allow engineers to quickly build scripts for various tasks, from device configuration to monitoring and troubleshooting.

Key Python Libraries for Network Automation

Here are some popular Python libraries tailored for network automation:

1. Netmiko: Simplifies SSH connections to network devices.

2. NAPALM: Offers a unified API for multi-vendor device management.

3. Paramiko: Ideal for handling SSH and SFTP connections.

4. pyATS/Genie: Cisco's robust library for automated testing and validation.

Practical Python Scripts for Everyday Tasks

1. Automating Device Configuration

This script pushes a configuration to a Cisco router using Netmiko:

from netmiko import ConnectHandler

device = {
    'device_type': 'cisco_ios',
    'host': '192.168.1.1',
    'username': 'admin',
    'password': 'password123',
}

config_commands = [
    'interface GigabitEthernet0/1',
    'description Configured by Python',
    'no shutdown',
]

connection = ConnectHandler(**device)
output = connection.send_config_set(config_commands)
print(output)
connection.disconnect()

2. Gathering Device Information

Use NAPALM to fetch and display device facts:

from napalm import get_network_driver

driver = get_network_driver('ios')

device = driver('192.168.1.1', 'admin', 'password123')

device.open()

facts = device.get_facts()

print(facts)

device.close()

3. Automated Network Health Check

Check the status of devices in a network and log the results:

from netmiko import ConnectHandler

devices = [

    {'device_type': 'cisco_ios', 'host': '192.168.1.1', 'username': 'admin', 'password': 'password123'},

    {'device_type': 'cisco_ios', 'host': '192.168.1.2', 'username': 'admin', 'password': 'password123'},

]

for device in devices:

    connection = ConnectHandler(**device)

    output = connection.send_command('show ip int brief')

    print(f"Device {device['host']}:\n{output}\n")

    connection.disconnect()

Best Practices for Python in Network Automation

• Start Small: Automate simple tasks like backups or interface checks before moving to complex workflows.

• Version Control: Use Git to manage and track changes to your automation scripts.

• Error Handling: Implement error handling to manage unexpected issues, like unreachable devices.

• Documentation: Comment your code to make it easier to understand and maintain.

• Test in a Lab: Always test scripts in a lab environment before deploying them in production.

Learning Python for Network Automation

If you're new to Python or looking to improve your skills, here are some resources:

• Books: Automate the Boring Stuff with Python by Al Sweigart.

• Courses: Python for Network Engineers on Udemy.

• Community: Join the Network Automation Slack Channel.

Conclusion

Python's role in network automation is transformative, offering tools to simplify complex tasks and eliminate manual work. By incorporating Python scripts into your workflow, you can improve efficiency, reduce errors, and focus on strategic objectives. Whether you're automating device configurations or performing network health checks, Python provides the flexibility and power needed to modernize network management.

Start small, experiment, and embrace the potential of Python to transform your day-to-day network operations. Happy automating!