[Openstack] rabbitmq rejects with invalid credentials

When rabbitmq log shows invalid credentials and rejects nova-services to join the cluster,

it probably means that the password is wrong.

nova-services in default use guest/guest (id/pw) for rabbitmq.

you can add (or change) the a user (or pw) with the following commands

add a user guest/guest

$ rabbitmqctl add_user guest guest

change the pw

$ rabbitmqctl change_password guest guest