Resources created under the hood

Creating a CDP environment on Azure with a private Flexible Server setup created by CDP involves creating several Azure resources, all of which are necessary to have a private setup that works out-of-the-box.

This private setup ensures that communication between CDP and the Azure Postgres server happens via a private IP address. However, cluster services do need to contact the Postgres server via FQDN, so the address needs to be resolvable from the VNet.

Resources created when using a CDP-managed Private DNS Zone

In the scenario where CDP creates the private DNS, several resources are created:

A Private DNS Zone: It is a DNS zone, part of an Azure-hosted DNS server. It has a fixed name (“flexible.postgres.database.azure.com”) but it is worth noting that any DNS Zone name ending with postgres.database.azure.com is usable in the “Bring your own private DNS” setup
A virtual network link between the zone and a VNet where the domain resolution should happen.
An A record within the zone: FQDN to IP address resolution. There is no reverse lookup.

When you delete the environment, the DNS zone and the network link that you provided will not be deleted.

Resources created when using your own private DNS zone

In this case the Private DNS Zone and the network link are provided by you and CDP creates the following:

CDP creates an A record within the zone: FQDN to IP address resolution. There is no reverse lookup.

When you delete the environment, the DNS zone and the network link that you provided will not be deleted.