What would you like to be added:
Secrets in Openstack can also be created using application credentials.
However the command gardenctl provider-env ... does not generate the necessary env variables.
There must be the following env variables available to get access to Openstack via application credentials:

OS_AUTH_URL=https://keystone.server/identity/v3
OS_AUTH_TYPE=v3applicationcredential
OS_APPLICATION_CREDENTIAL_ID=6cb5fa6a13184e6fab65ba2108adf50c
OS_APPLICATION_CREDENTIAL_SECRET=glance_secret

or

OS_AUTH_URL=https://keystone.server/identity/v3
OS_AUTH_TYPE=v3applicationcredential
OS_USERNAME=glance
OS_USER_DOMAIN_NAME=Default
OS_APPLICATION_CREDENTIAL_NAME=glance_cred
OS_APPLICATION_CREDENTIAL_SECRET=glance_secret

All other env variables beside these ones must be removed. Documentation can be found here https://docs.openstack.org/keystone/latest/user/application_credentials.html.

Why is this needed: