You can use cloud kitty,

CloudKitty proposes the following way to interact with it :

Horizon API Python Binding

refer to https://wiki.openstack.org/wiki/Cloud...

The Ceilometer project is a data collection service that provides the ability to normalize and transform data across all current OpenStack core components with work underway to support future OpenStack components.

refer to https://docs.openstack.org/ceilometer...

There are billing services for OpenStack (CloudKitty), and metric collection services that feed into it (Ceilometer/Gnocchi, Monasca). It may be possible to repurpose one of those for measuring uptime (although I'm not sure if the measurements will be granular enough for your purposes).

Masakari is a service for providing High Availability of tenant workloads, so that might be a piece to start looking at extending.