"""Install a helm chart
:param cluster_uuid str: The UUID of the cluster to install to
- :param kdu_model str: The name or path of a bundle to install
+ :param kdu_model str: chart/reference (string), which can be either
+ of these options:
+ - a name of chart available via the repos known by OSM
+ (e.g. stable/openldap, stable/openldap:1.2.4)
+ - a path to a packaged chart (e.g. mychart.tgz)
+ - a path to an unpacked chart directory or a URL (e.g. mychart)
:param kdu_instance: Kdu instance name
:param atomic bool: If set, waits until the model is active and resets
the cluster on failure.