authentication = [
  {
    backend = ldap
    base_dn = "uid=${username},ou=testdevice,dc=emqx,dc=io"
    filter = "(& (objectClass=mqttUser) (uid=${username}))"
    mechanism = password_based
    method {
      is_superuser_attribute = isSuperuser
      password_attribute = userPassword
      type = hash
    }
    password = public
    pool_size = 8
    query_timeout = "5s"
    request_timeout = "10s"
    server = "localhost:1389"
    username = "cn=root,dc=emqx,dc=io"
  }
]