Original comment by @jguay:

Kibana version:
6.0.0
Elasticsearch version:
6.0.0
Description of the problem including expected versus actual behavior:
Customer would like to use kibana with anonymous user but using new "kibana_dashboard_only_user" role's restricted UI
Steps to reproduce:

1. Define anonymous_user in elasticsearch with role kibana_dashboard_only_user
2. Kibana displays a login page so it's not possible to use the anonymous user
3. xpack.security.enable: false in kibana.yml will partially workaround if user also has cluster/monitor privilege. However user will have unrestricted UI (hence be able to create any dangerous vizualisation and get errors when trying to save them to .kibana)

Describe the feature:
Feature would be to have new setting for kibana like "xpack.security.anonymous.enable" which when set to true would remove the login page and go straight in using anonymous user against ES
After this user gets logged in, the logout button should be removed. Or even better allow option to replaced by "login" button if another option xpack.security.anonymous.redirecturl is set (so that user is redirected to another kibana instance using standard security)