Admin is able to see user tenants' instances details via CLI (nova show xxxx) after admin.rc is sourced.

But how to do it with REST API?

When generating a token, tenant name must be input. If I use admin as tenant name together with admin credential to generate a token, it cant be used to GET user tenants' instance detail.

{"auth": {"tenantName": "admin", "passwordCredentials": {"username": "admin", "password": "xxxx"}}} --> token is only for admin tenant.

If I use user tenant name together with admin credential, token cant be generated.

{"auth": {"tenantName": "user-tenant", "passwordCredentials": {"username": "admin", "password": "xxxx"}}} --> token fail.