roles:
-- [mon.a, mon.c, mgr.y, osd.0, osd.1, osd.2, osd.3, client.0]
-- [mon.b, mgr.x, osd.4, osd.5, osd.6, osd.7, client.1]
+- [mon.a, mon.c, mgr.y, osd.0, osd.1, osd.2, osd.3, client.0, node-exporter.a]
+- [mon.b, mgr.x, osd.4, osd.5, osd.6, osd.7, client.1, prometheus.a, node-exporter.b]
openstack:
- volumes: # attached to each instance
count: 4