Comment 8 for bug 1777939

It seems that even the services initially able to connect the rabbitmq, somehow degraded and lost the connectivity, for example here is a sippet for ironic-conductor:

2018-06-22 14:43:33.867 6 INFO oslo.messaging._drivers.impl_rabbit [-] [d4784c4c-0857-4659-aed9-61a5fdca1cf2] Reconnected to AMQP server on undercloud.internalapi.localdomain:5672 via [amqp] client with port 54148.
...
2018-06-22 14:49:40.124 6 ERROR oslo.messaging._drivers.impl_rabbit [req-2aa9f436-87a2-4e16-aaf3-cd3529292b26 - - - - -] Unable to connect to AMQP server on undercloud.internalapi.localdomain:5672 after None tries: (0, 0): (403) ACCESS_REFUSED - Login was refused using authentication mechanism AMQPLAIN. For details see the broker logfile.: AccessRefused: (0, 0): (403) ACCESS_REFUSED - Login was refused using authentication mechanism AMQPLAIN. For details see the broker logfile.