How to figure out configuration changes a service made to the modified devices?

[erichgaede]

Hello NSO Community,

currently I'm supporting NSO pre-sales activities and thereby a question came up from customer side, which I could not directly answer.

For problem analysis and troubleshooting in production environment it would be useful, if one could figure out the configuration changes a service made to devices.

I tested with a simple template based service 'l2vpn' from a former NSO training.

Figuring out the devices modified by a certain existing service instance is quite easy:

admin@ncs# show services l2vpn CE11-to-CE21 modified
modified devices [ PE11 PE21 ]

Just as simple it is to figure out the history of this service instance – all the transactions impacting this service instance:

admin@ncs# show configuration commit list services l2vpn CE11-to-CE21
2019-08-09 09:47:24
SNo. ID       User       Client      Time Stamp          Label       Comment
~~~~ ~~       ~~~~       ~~~~~~      ~~~~~~~~~~          ~~~~~       ~~~~~~~
1010 10108    admin      cli         2019-08-08 17:45:54 l2vpn       CE11-to-CE21
1010 10107    admin      cli         2019-08-08 17:32:17 l2vpn       CE11-to-CE21
1010 10106    admin      cli         2019-08-08 17:23:54 l2vpn       CE11-to-CE21

In this example the transactions are service instance creation and to changes.

BUT I did not find a way to display the changes these past transactions made on devices PE11 and PE21. How can this be done?
Also I could not find a way to show the portions in current configurations of devices PE11 and PE21 related to service instance CE11-to-CE21.

A workaround is to 'un-deploy' the service instance with 'dry-run'. This shows what will be removed on the devices and therefore is related to the service instance. I suppose, stuff that is shared by multiple service instances, won't show up this way, but I didn't test it. Maybe this could be overcome with option 'ignore-refcount'.
For me this is a quite poor workaround and I hope somebody knows a better / real solution.

As the scenario outlined by the customer is on production environment, device traces are not a solution. And the transactions may have taken place sometime in the past.

Each hint very much appreciated.

Thanks a lot in advance.

[hniska · Accepted solution]

Use the service action get-modifications

admin@ncs% request vpn l3vpn volvo get-modifications

[erichgaede]

Thanks a lot for quick help. This shows me the impact on devices of the current service instance configuration.

Is there also a way to look back in the past and get the modifications each transaction made to devices?

[hniska · Accepted solution]

Only by looking in the logs and/or rollback files.