Comment 4 for bug 1587821

FYI: "oslo.config", which generates the conf file, provides a "wrap_width" attribute (default: 70 chars)[1]. Nova sets it at 79 chars [2], which sometimes results in ugly line breaks if your line is 80 chars (AFAIK the default in the pep8 checks). I tend to make the manual line breaks in Nova config option multi-line help texts at ~77 chars. That tends to create the best output.

References:
[1] https://github.com/openstack/oslo.config/blob/d829109cb47bb19b5c25023ed50e7476c98d33e9/oslo_config/generator.py#L113
[2] https://github.com/openstack/nova/blob/a1f74c7dba758b0ab28d746fa69d814e7a55c7bf/etc/nova/nova-config-generator.conf#L3