In addition to the web based user interface (Horizon dashboard), you can also use the OpenStack API directly from the commandline. In order to do so, you first need to install the respective tools. The tools are Python based such that you ideally start with a Python virtual environment.
$ python3 -m venv openstack
$ source openstack/bin/activate
$ pip install python-openstackclient
Next, you will need one of two configuration files from the web interface. One of them, the project-openrc.sh file, sets up environment variables to guide the OpenStack client's behavior. It must be sourced before using the "openstack" command. The other file, clouds.yaml, provides a YAML based configuration that must be located in your current working directory or under ~/.config/openstack/clouds.yaml.
Depending on how you authenticated at HDF Cloud in the first place, you can retrieve these files from one of two places.
If you used your JSC account to authenticate to HDF Cloud, you can retrieve both files from the web UI under Project → API Access as shown in the figure below.
If you used the Helmholtz AAI to authenticate to HDF Cloud, you will need to create so called application credentials which you can then use from the commandline interface. Go to Identiy → Application Credentials in order to create them. The default settings work out of the box, only the name is a mandatory field.
After creation, you will have the opportunity to download the above mentioned files from the result dialog, as shown below.