Comment 32 for bug 1680523

As of 2019-07, this looks to be resolved. It's still possible to run into hiccups, but it works when one avoids edge cases.

[Without logging in to the azure CLI]

$ juju add-credential azure
Enter credential name: az-test

Auth Types
  interactive
  service-principal-secret

Select auth type [interactive]:

Enter subscription-id: ed185b28-....-....-....-........bfc3

Initiating interactive authentication.

To sign in, use a web browser to open the page https://microsoft.com/devicelogin and enter the code HD3S77LNH to authenticate.

Authenticated as "c64de0e0-....-....-....-9f05be734b4c 33a8a870-....-....-....-71642935532b".
ERROR finalizing credential: service principal not found

[After logging in with `az login`]

$ juju add-credential azure
Enter credential name: az-test2

Auth Types
  interactive
  service-principal-secret

Select auth type [interactive]:

Enter subscription-id (optional): ed185b28-....-....-....-........bfc3

Initiating interactive authentication.

To sign in, use a web browser to open the page https://microsoft.com/devicelogin and enter the code H3QPPZVX6 to authenticate.

Authenticated as "c64de0e0-....-....-....-9f05be734b4c 33a8a870-....-....-....-71642935532b".
Credential "az-test2" added locally for cloud "azure".