Network Configuration Diffing
Lately, I was working on a Python script to help my team and me manage interface configurations on Cisco switches. One thing my team asked for was a way to see what changes the script was making to the configurations before and after it did its thing. My first thought was to use Python’s difflib module for this. It’s handy for comparing two sequences and showing the differences.
To give you an idea, here’s an example of what the output looked like using the difflib module.
import difflib
before = """
interface HundredGigE1/0/3
description Dummy interface
switchport mode access
switchport access vlan 10
end
"""
after = """
interface HundredGigE1/0/3
description Dummy interface
switchport mode access
switchport access vlan 20
end
"""
diff = difflib.ndiff(before.splitlines(), after.splitlines())
print("\n".join(diff))
The output of the above script is as below:
interface HundredGigE1/0/3
description Dummy interface
switchport mode access
- switchport access vlan 10
? ^
+ switchport access vlan 20
? ^
end
The team wasn’t too thrilled with the output because it was kinda tricky to read. You really had to know what you were looking for to make sense of it.
While looking for a suitable solution, I came across Continue reading
