Two-Way List Diffing w/ Key

[ghost]

ref #167

I've been trying to figure out this for show bgp neighbors pre/post list diffing

Two-Way List Diffing Required

• Unique key between lists: /bgp-information/bgp-peer/peer-id:text()
• Post[] shall have all the peers as seen in Pre[] in Established state
• Post[] shall not have any new peers compared to Pre[]

Difficulty arises from two-way diffing dynamic lists I see no way of doing..

@vnitinv @ydnath

My guess so far is something like this having to use template and XPath to cross-match[]:

test_command_bgp:
  - command: show bgp neighbor
{% for BpeerID in how-to-get-BpeerIDs? %}
  - iterate:
      xpath: '/bgp-information/bgp-peer/[peer-id:text()={{BpeerID}]'
      tests:
        - exists       # element in which test is performed
          err: "Test Failed!! peer-address got changed, it is now <{{post['peer-address']}}>"
          info: "Test succeeded!! peer-address is equal to <{{post['peer-address']}}>"

The above would need to have another list context from B-perspective so all the added peers could be found

Is this something I need to write a module for? I am new sorry :)

Cheers

[ydnath]

@titusfoo The module approach would definitely give you more control as you can build contexts within your code.

[ghost]

@ydnath Two-Way list diff is pretty common use-case for many audit scenarios e.g. pre/post migrations to make sure all the same pre peers came up on post. Can we flag this as enhancement if nothing on base functionality yet?

[ydnath]

@titusfoo We will evaluate this and check if a generic two-way diff can be implemented. Thank you.