In scenario where upgrade gets config from minigraph, it could miss tacacs credentials as they are not in minigraph. Hence restore explicitly upon load-minigraph, if present.
- Why I did it
Upon boot, when config migration is required, the switch could load config from minigraph. The config-load from minigraph would wipe off TACACS key and disable login via TACACS, which would disable all remote user access. This change, would re-configure the TACACS if there is a saved copy available.
- How I did it
When config is loaded from minigraph, look for a TACACS credentials back up (tacacs.json) under /etc/sonic/old_config. If present, load the credentials into running config, before config-save is called.
- How to verify it
Remove /etc/sonic/config_db.json and do an image update. Upon reboot, w/o this change, you would not be able ssh in as remote user. You may login as admin and check out, "show tacacs" & "show aaa" to verify that tacacs-key is missing and login is not enabled for tacacs.
With this change applied, remove /etc/sonic/config_db.json, but save tacacs & aaa credentials as tacacs.json in /etc/sonic/. Upon reboot, you should see remote user access possible.