DNS Framework: tenants cannot own DNS servers or vanity zones (no account/domainid on addDnsServer/createDnsZone) #14525

ISSUE TYPE

• Improvement Request / Bug Report

COMPONENT NAME

DNS Framework (PowerDNS provider), API, UI

CLOUDSTACK VERSION

4.23.0.0

SUMMARY

The new DNS Framework works well for provider-owned zones, but in a multi-tenant
cloud there is no way for a tenant to manage a zone for a domain they own
(e.g. customer.com). Every tenant zone is forced under the public server's
suffix, and the admin cannot create a server entry or zone on a tenant's behalf.

OBSERVED BEHAVIOUR

1. addDnsServer called by a non-root account fails with
   "This API can only be called by root admin".
   The documentation states that admins and domain admins can create public
   DNS servers, so either the docs or the permission check is wrong.
2. Only one DNS server entry per account + URL is allowed
   ("This Account already has a DNS server integration for URL: ...").
3. addDnsServer and createDnsZone have no account, domainid or
   projectid parameters (verified with list apis ... filter=params),
   so root cannot create a server entry or zone owned by a tenant.
4. Zones created by root are owned by root and are not visible to tenants.
5. Tenants creating zones on a public server are always restricted to the
   single publicdomainsuffix.

Result: a tenant who owns customer.com and delegates it to our nameservers
cannot manage that zone through CloudStack. The only workarounds are manual
management by root, a separate DNS UI outside CloudStack, or CNAMEs from the
vanity zone into a suffixed tenant zone.

USE CASE

• Provider runs a PowerDNS cluster and wants to offer managed DNS to tenants.
• Default: tenants self-serve zones under cloud.provider.example
  (works today).
• Some tenants own their own domains (customer.com), delegate them to the
  provider's nameservers, and need to manage records (A, MX, TXT, CNAME)
  and VM auto-registration for them, without access to the PowerDNS API key.

PROPOSED IMPROVEMENTS

1. Add account + domainid (and projectid) to addDnsServer and
   createDnsZone, consistent with other CloudStack resource APIs, so root
   can provision a server entry or zone owned by a tenant.
2. Alternatively, an API to change zone ownership
   (e.g. assignDnsZone / updateDnsZone account=... domainid=...).
3. Allow domain admins to call addDnsServer as documented, or update the
   docs if root-only is intended.
4. Allow multiple allowed suffixes per public server, or per-domain suffix
   rules (e.g. domain ROOT/CustomerA may create customer.com).
5. Optional: an ownership verification step (TXT challenge) before a tenant
   can create a zone outside the public suffix, to prevent zone squatting.

STEPS TO REPRODUCE

1. As root admin, add a public PowerDNS server with publicdomainsuffix=cloud.provider.example.
2. As a tenant user, try to create zone customer.com -> forced under the suffix.
3. As a tenant user or domain admin, try addDnsServer -> "can only be called by root admin".
4. As root, try addDnsServer again with the same URL -> "already has a DNS server integration for URL".
5. As root, create zone customer.com -> owned by root, not visible to the tenant.