Automate private DNS record creation

Learn to how to automatically create a DNS record whenever a floating IP is assigned to a virtual machine.

Setting up the DNS Network

1. Navigate to Network > Networks, click on the Network ID from the list of your Networks.

   

2. Select Subnets and click Edit.

   

3. Type in DNS name servers with Controller VIP.

   

Create DNS Zone

1. Navigate Project > Network > DNS Zones, click on the CREATE ZONE.

   

2. Create zone with a preferred/registered domain name.

   

Connect to console

Accessing CubeCOS cluster VIP via SSH

    $ ssh [email protected]
    Warning: Permanently added '172.16.1.20' (ED25519) to the list of known hosts.
    [email protected]'s password:
    Welcome to Cube Appliance
    License (type: trial) is valid for 46 days
    Enter "help" for a list of available commands
    cc1>

Setting a prefix dns_domain on a private network through CLI

    cc1> iaas network network_set
    Select domain:
    1: Default
    Enter index: 1
    Select tenant:
    1: admin
    Enter index: 1
    Select network:
    1: public
    2: pri_192
    Enter index: 2
    Select type:
    1: name
    2: description
    3: qos-policy
    4: no-qos-policy
    5: dns-domain
    6: no-dns-domain
    Enter index: 5
    Input value: bigstack.local.
    Updated network: a35cef55-02fa-49bf-9a1e-f844584544de

Check up the dns_domain prefix

    cc1> iaas network network_show
    Select domain:
    1: Default
    Enter index: 1
    Select tenant:
    1: admin
    Enter index: 1
    Select network:
    1: public
    2: pri_192
    Enter index: 2
    +---------------------------+--------------------------------------+
    | Field                     | Value                                |
    +---------------------------+--------------------------------------+
    | admin_state_up            | UP                                   |
    | availability_zone_hints   |                                      |
    | availability_zones        |                                      |
    | created_at                | 2025-05-15T06:39:24Z                 |
    | description               |                                      |
    | dns_domain                | bigstack.local.                      |
    | id                        | a35cef55-02fa-49bf-9a1e-f844584544de |
    | ipv4_address_scope        | None                                 |
    | ipv6_address_scope        | None                                 |
    | is_default                | None                                 |
    | is_vlan_transparent       | None                                 |
    | mtu                       | 1442                                 |
    | name                      | pri_192                              |
    | port_security_enabled     | True                                 |
    | project_id                | b8d8d3f84f82451f9b6b6bbd1b115ec3     |
    | provider:network_type     | geneve                               |
    | provider:physical_network | None                                 |
    | provider:segmentation_id  | 2142                                 |
    | qos_policy_id             | None                                 |
    | revision_number           | 3                                    |
    | router:external           | Internal                             |
    | segments                  | None                                 |
    | shared                    | False                                |
    | status                    | ACTIVE                               |
    | subnets                   | e5976294-4e89-4f0d-b97f-2eec230d3758 |
    | tags                      |                                      |
    | updated_at                | 2025-05-15T06:40:48Z                 |
    +---------------------------+--------------------------------------+

Associate Floating IP to your Instances

1. Navigate to Project > Compute > Instance.

2. Hover over More, then Related Resources, and click Associate Floating IP.

   

• An IP 172.16.1.25 has been associated to your instance dns-test

  

Check the zone record set of bigstack.local.

• A Record has been created according to your instance's hostname dns-test.bigstack.local.is mapping 172.16.1.25

  

Check the DNS with nslookup

• open a terminal and run nslookup dns-test.bigstack.local. 10.32.31.10

  ❯ nslookup dns-test.bigstack.local. 10.32.31.10
  Server:  10.32.31.10
  Address: 10.32.31.10#53

  Name: dns-test.bigstack.local
  Address: 172.16.1.25

Summary

In this use case, the address of a floating IP is published in the external DNS service in conjunction with the dns_name of its associated port and the dns_domain of the port’s network. The steps to execute in this use case are the following:

• Assign a valid domain name to the network’s dns_domain attribute. This name must end with a period (.).
• Boot an instance or alternatively, create a port specifying a valid value to its dns_name attribute. If the port is going to be used for an instance boot, the value assigned to dns_name must be equal to the host name that the Compute service will assign to the instance. Otherwise, the boot will fail.
• Create a floating IP and associate it to the port.