DNS as a Service

DNS as a Service (DNSaaS) provides automatic DNS management for OpenStack resources.

The service is based on OpenStack Designate, which provides DNS zone and record management and integrates with OpenStack Networking (Neutron).

Projects with DNS enabled receive a dedicated DNS zone in the form:

<project-name>.dyn.oliver.platform.cloud.e-infra.cz.

DNS for virtual machines

When a virtual machine is created in a DNS-enabled project, its name is used to generate the DNS hostname.

For example:

VM name: dns-test
Project name: dns-example

The project DNS zone would be:

dns-example.dyn.oliver.platform.cloud.e-infra.cz.

When a Floating IP is associated with the virtual machine, OpenStack automatically creates an A record in that zone using the VM name:

dns-test.dns-example.dyn.oliver.platform.cloud.e-infra.cz. A 78.128.234.123

The resulting hostname follows this format:

<vm-name>.<project-name>.dyn.oliver.platform.cloud.e-infra.cz.

The hostname can then be resolved:

dig dns-test.dns-example.dyn.oliver.platform.cloud.e-infra.cz.

;; ANSWER SECTION:
dns-test.dns-example.dyn.oliver.platform.cloud.e-infra.cz. 3600 IN A 78.128.234.123

Services running on the virtual machine can be accessed using the hostname, provided that the required ports are allowed by the virtual machine’s security groups.

Checking DNS zones and records

List the DNS zones available to the current project:

openstack zone list

Show details of a zone:

openstack zone show <zone.>

List DNS records in a zone:

openstack recordset list <zone.>

Info

Note: DNS changes may not be visible immediately on public resolvers due to caching. With the default TTL of 3600 seconds, cached responses may remain for up to one hour. During this time, the hostname may not resolve correctly for all users. You can check public resolvers directly with:

dig @8.8.8.8 <hostname>
dig @1.1.1.1 <hostname>

DNS as a Service

DNS for virtual machines

Checking DNS zones and records

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