MGR_MODULE_ERROR: 2 mgr modules have failed || Unable to access Ceph dashboard and Prometheus portal

Issue

• Ceph MGR modules Dashboard and Prometheus are failed to run. As a result Ceph is reporting below health error message:

  HEALTH_ERR 2 mgr modules have failed
  [ERR] MGR_MODULE_ERROR: 2 mgr modules have failed
  Module 'dashboard' has failed: OSError("No socket could be created -- (('x.x.x.x', 8443): [Errno 99] Cannot assign requested address)",)
  Module 'prometheus' has failed: OSError("No socket could be created -- (('x.x.x.x', 9283): [Errno 99] Cannot assign requested address)",)