Improper increment of commit-ids with confd 8.0 with restconf

General
1

Hi Team, I am facing an issue where commit-id is getting improperly incremented when restconf is used. This unusual behavior is causing issues while doing a configuration rollback since we are not sure if each command increased commit IDs by 1 or 2.

confd version: 8.0

I can see two issues:

  1. If I did few CLI commits, and then did a change via restconf, commit-id is incremented by 2 (10022–> 10024)
  2. If I pushed a config via restconf that already exists, commit-id is not incremented (expected since there is no delta), but after this if I do another configuration via restconf which does have a config change, commit-ids are incremented by 2. (10027–> 10029)

admin@kumar-abhijeet-10-164-33-141-08-28-06-44 08:26:21# show configuration commit list
2023-08-28 08:26:48
SNo. ID User Client Time Stamp Label Comment

0    10029    admin      rest        2023-08-28 08:26:42             
1    10027    admin      rest        2023-08-28 08:25:51             
2    10026    admin      rest        2023-08-28 08:24:36             
3    10025    admin      rest        2023-08-28 08:22:36             
4    10024    admin      rest        2023-08-28 08:21:07             
5    10022    admin      cli         2023-08-24 12:03:05             
6    10021    admin      cli         2023-08-24 12:01:36             
7    10020    admin      cli         2023-08-24 12:00:44             
8    10019    admin      cli         2023-08-24 11:59:45
2

I don’t think there is any contract as to behavior of rollbacks’ fixed-number attribute, except that for given rollback it never changes. If you need to refer to rollbacks relatively to the most recent, use rollback id which starts with 0 for the most recent and increases by 1.

3

Hi mvf, thanks for your answer.

I checked how we are doing rollback and why this changed behavior is affecting us.
We use this restconf api for rollbacks–> /restconf/data/tailf-rollback:rollback-files/apply-rollback-file
Instead of providing which commits (fixed-number) we need to revert, we specify a number that is a diff between when we started configuration and where we are now. For example, If I want to revert configuration done via rest, I will do 10029-1022-1=6.

Call above api with this xml

<input xmlns="http://tail-f.com/ns/rollback">
 <id>6</id>
</input>

But, here is the problem, I endup reverting configurations done via cli too.
If the commit-ids were sequential, the revert will work correctly 10027-10022-1=4.

Because commit-ids are getting incremented by 2 infrequently in between, the application cannot co-related which id to revert to based on commit-ids returned in initial and final config.

4

So there is certain rollback you want to apply and you know its fixed-number? In that case just use it instead of its id, i.e. send

<input xmlns="http://tail-f.com/ns/rollback">
  <fixed-number>10022</fixed-number>
</input>