How to prevent users from deleting their account. entry on EJABBERD server?

Question

Ejabberd

Hello! There are a couple of questions on setting up EJABBERD, I could not find an answer in Google.
When you delete an account in the client. record, it can also be deleted from the server - how to disable it?
Is there any way to prevent users from adding contacts to their address book?
How to prohibit the creation of rooms and conferences (maybe this is the same thing)?

Answer 1

Conference rights (MultiUser Conference, muc) are set in the config.
muc_admin - who has admin rights
muc_create - who can create conferences
muc - who can join conferences
All three parameters use the control lists specified in the acl parameter.

Example

acl:
   admin:
      user:
         - "pupkin_v": "example.com"
         - "sidorov": "example.com"
   local:
       server: "example.com"

access_rules:
  ...
  muc_admin:
    - allow: admin
  muc_create:
    - allow: local
  muc:
    - allow
  ...

modules:
  ...
  mod_muc:
    db_type: mnesia
    access:
      - allow
    access_admin: muc_admin
    access_create: muc_create
    access_persistent: muc_create
  ...

For centralized user management, you need to connect LDAP (ejabberd_auth_ldap) or MySQL (ejabberd_auth_sql).
For the general list of contacts - respectively mod_shared_roster_ldap and mod_shared_roster_sql.
For business cards - mod_vcard_ldap, mod_vcard_sql and mod_vcard_xupdate.