Using DNS as a service

Using DNS as a Service (DNSaaS)

Overview

OpenStack's Designate provides a Domain Name Service as a service (DNSaaS).
This means that zones and records can be configured within OpenStack via an API (also see the reference guide) and will be queryable via DNS protocol from public nameservers run by SysEleven.
This functionality can be very handy to automate updates to dns records caused by failovers or deployments, it also facilitates automated renewal of Let's Encrypt SSL certificates.

The tutorial is intended to make you familiar with the main functionality and aware of the presence of more advanced features of the DNS service of the SysEleven Stack.
It shows examples for the openstack CLI, discovering the functionality in the GUI is left as an exercise to the user.
The API can also be used with Terraform, have a look at our Terraform examples.

Prerequisites

You may need to install the designate client (plugin).

(sudo) pip install python-openstackclient python-designateclient

Managing Zones

Create a (primary) zone

First you create a dns zone with the following command:

$ openstack zone create --email "email@domain.example" domain.example.
+----------------+--------------------------------------+
| Field          | Value                                |
+----------------+--------------------------------------+
| action         | CREATE                               |
| attributes     |                                      |
| created_at     | 2019-06-24T15:41:22.000000           |
| description    | None                                 |
| email          | email@example.de                     |
| id             | 01234567-89ab-cdef-0123-456789abcdef |
| masters        |                                      |
| name           | domain.example.                      |
| pool_id        | 14234f0f-1234-4444-6789-758006f43802 |
| project_id     | 0123456789abcdef0123456789abcdef     |
| serial         | 1561390882                           |
| status         | PENDING                              |
| transferred_at | None                                 |
| ttl            | 21600                                |
| type           | PRIMARY                              |
| updated_at     | None                                 |
| version        | 1                                    |
+----------------+--------------------------------------+

You can also create subzones with the following command:

openstack zone create --email "email@domain.example" sub.domain.example.

To indicate a valid email address is a requirement by the relevant DNS standards (RFC) and thus also mandatory for OpenStack.

The zone name can be any publicly available domain name or subdomain name. Top level domain names are not allowed.

Create a secondary (slave) zone

To create a secondary or slave zone, whose content is actually managed by (and obtained from) the primary or master server, you need to specify the master server(s):

$ openstack zone create --type SECONDARY --masters 123.45.67.89 -- secondary.domain.example.
+----------------+--------------------------------------+
| Field          | Value                                |
+----------------+--------------------------------------+
| action         | CREATE                               |
| attributes     |                                      |
| created_at     | 2019-06-24T15:43:56.000000           |
| description    | None                                 |
| email          | hostmaster@example.com               |
| id             | 01234567-89ab-cdef-0123-456789abcdef |
| masters        | 123.45.67.89                         |
| name           | secondary.domain.example.            |
| pool_id        | 14234f0f-1234-4444-6789-758006f43802 |
| project_id     | 0123456789abcdef0123456789abcdef     |
| serial         | 1                                    |
| status         | PENDING                              |
| transferred_at | None                                 |
| ttl            | 21600                                |
| type           | SECONDARY                            |
| updated_at     | None                                 |
| version        | 1                                    |
+----------------+--------------------------------------+

Note, that the shown email-address hostmaster@example.com is a placeholder by openstack, any given value will be ignored for secondary zones.

Attention: Because more than one master IP address can be specified, the list must either be terminated with a double dash or the whole parameter with its list be moved to the end of the command line.

openstack zone create secondary.domain.example. --type SECONDARY --masters 123.45.67.89

Have the zone delegated to the SysEleven Stack nameservers

The delegation of a zone will be done by the appropriate registry for the top level domain where the registered domain belongs to. Most likely it will be triggered via your registrar or reseller. They need to know the nameservers that the domain shall be delegated to. You can obtain that list with the following command

$ openstack recordset list domain.example. --type ns
+--------------------------------------+-----------------+------+---------------------------+--------+--------+
| id                                   | name            | type | records                   | status | action |
+--------------------------------------+-----------------+------+---------------------------+--------+--------+
| 01234567-89ab-cdef-0123-456789abcdef | domain.example. | NS   | ns02.cloud.syseleven.net. | ACTIVE | NONE   |
|                                      |                 |      | ns04.cloud.syseleven.net. |        |        |
|                                      |                 |      | ns03.cloud.syseleven.net. |        |        |
|                                      |                 |      | ns01.cloud.syseleven.net. |        |        |
+--------------------------------------+-----------------+------+---------------------------+--------+--------+

In this case you will have to give the nameserver names ns01.cloud.syseleven.net thru ns04.cloud.syseleven.net to your registrar. They will then arrange for the delegation. Some registries perform sanity checks on the nameservers before executing a delegation. If you encounter problems with the registry, please contact our support.

Updating zones

We can change or unset the description and change the email address of primary zones like this:

$ openstack zone set --description "Example Domain" --email other@domain.example domain.example.de.
+----------------+--------------------------------------+
| Field          | Value                                |
+----------------+--------------------------------------+
| action         | UPDATE                               |
| attributes     |                                      |
| created_at     | 2019-06-24T15:41:22.000000           |
| description    | Example Domain                       |
| email          | other@domain.example                 |
| id             | 01234567-89ab-cdef-0123-456789abcdef |
| masters        |                                      |
| name           | domain.example.                      |
| pool_id        | 14234f0f-1234-4444-6789-758006f43802 |
| project_id     | 0123456789abcdef0123456789abcdef     |
| serial         | 1561628292                           |
| status         | PENDING                              |
| transferred_at | None                                 |
| ttl            | 21600                                |
| type           | PRIMARY                              |
| updated_at     | 2019-06-27T09:38:12.000000           |
| version        | 3                                    |
+----------------+--------------------------------------+
$ openstack zone set --no-description --email email@domain.example domain.example.de.
+----------------+--------------------------------------+
| Field          | Value                                |
+----------------+--------------------------------------+
| action         | UPDATE                               |
| attributes     |                                      |
| created_at     | 2019-06-24T15:41:22.000000           |
| description    | None                                 |
| email          | email@domain.example                 |
| id             | 01234567-89ab-cdef-0123-456789abcdef |
| masters        |                                      |
| name           | domain.example.                      |
| pool_id        | 14234f0f-1234-4444-6789-758006f43802 |
| project_id     | 0123456789abcdef0123456789abcdef     |
| serial         | 1561628369                           |
| status         | PENDING                              |
| transferred_at | None                                 |
| ttl            | 21600                                |
| type           | PRIMARY                              |
| updated_at     | 2019-06-27T09:39:29.000000           |
| version        | 4                                    |
+----------------+--------------------------------------+

We can also change the masters of secondary zones like this:

$ openstack zone set --masters 123.45.67.88 -- secondary.domain.example.de.
+----------------+--------------------------------------+
| Field          | Value                                |
+----------------+--------------------------------------+
| action         | UPDATE                               |
| attributes     |                                      |
| created_at     | 2019-06-24T15:43:56.000000           |
| description    | None                                 |
| email          | hostmaster@example.com               |
| id             | 01234567-89ab-cdef-0123-456789abcdef |
| masters        | 123.45.67.88                         |
| name           | secondary.domain.example.            |
| pool_id        | 14234f0f-1234-4444-6789-758006f43802 |
| project_id     | 0123456789abcdef0123456789abcdef     |
| serial         | 1                                    |
| status         | PENDING                              |
| transferred_at | None                                 |
| ttl            | 21600                                |
| type           | SECONDARY                            |
| updated_at     | 2019-06-27T09:32:27.000000           |
| version        | 2                                    |
+----------------+--------------------------------------+

It is however not possible to change the type between master and secondary zones, they have to be removed and recreated as the new type.

Removing zones

$ openstack zone delete secondary.domain.example.de.
+----------------+--------------------------------------+
| Field          | Value                                |
+----------------+--------------------------------------+
| action         | DELETE                               |
| attributes     |                                      |
| created_at     | 2019-06-24T15:43:56.000000           |
| description    | None                                 |
| email          | hostmaster@example.com               |
| id             | 01234567-89ab-cdef-0123-456789abcdef |
| masters        | 123.45.67.88                         |
| name           | secondary.domain.example.            |
| pool_id        | 14234f0f-1234-4444-6789-758006f43802 |
| project_id     | 0123456789abcdef0123456789abcdef     |
| serial         | 1                                    |
| status         | PENDING                              |
| transferred_at | None                                 |
| ttl            | 21600                                |
| type           | SECONDARY                            |
| updated_at     | 2019-06-27T09:46:53.000000           |
| version        | 7                                    |
+----------------+--------------------------------------+
$ openstack zone delete domain.example.de.
+----------------+--------------------------------------+
| Field          | Value                                |
+----------------+--------------------------------------+
| action         | DELETE                               |
| attributes     |                                      |
| created_at     | 2019-06-24T15:41:22.000000           |
| description    | None                                 |
| email          | email@domain.example                 |
| id             | 01234567-89ab-cdef-0123-456789abcdef |
| masters        |                                      |
| name           | domain.example.                      |
| pool_id        | 14234f0f-1234-4444-6789-758006f43802 |
| project_id     | 0123456789abcdef0123456789abcdef     |
| serial         | 1561628369                           |
| status         | PENDING                              |
| transferred_at | None                                 |
| ttl            | 21600                                |
| type           | PRIMARY                              |
| updated_at     | 2019-06-27T09:46:59.000000           |
| version        | 7                                    |
+----------------+--------------------------------------+

Frequent problems and their solutions

Problem Solution
Duplicate Zone Zone has already been created, either by you or by another user. See collisions.
Invalid TLD Zone names must be within a known top level domain. Contact us if you believe the top level domain is valid.
More than one label is required It is not allowed to create a zone for a top level domain.
Zone name cannot be the same as a TLD It is not allowed to create a zone for a known top level domain.
u'domain.example' is not a 'domainname' Domain names must be fully qualified, i.e. end with a dot.
Please delete any subzones before deleting this zone This is a security measure to prevent you from losing control over your zone after having transferred subzones.
Unable to create subzone in another tenants zone The subzone must be created by the tenant owning the zone and can then be transferred.
Unable to create zone because another tenant owns a subzone of the zone The zone must be created by the tenant owning the subzone and can then be transferred.
'masters' has more items than allowed This can mean you're trying to specify masters for a master zone.

Managing Record(set)s

Creating record(set)s

$ openstack recordset create --type A --record 123.45.67.89 domain.example. www.domain.example.
+-------------+--------------------------------------+
| Field       | Value                                |
+-------------+--------------------------------------+
| action      | CREATE                               |
| created_at  | 2019-06-21T15:39:36.000000           |
| description | None                                 |
| id          | 01234567-89ab-cdef-0123-456789abcdef |
| name        | www.domain.example.                  |
| project_id  | 0123456789abcdef0123456789abcdef     |
| records     | 123.45.67.89                         |
| status      | PENDING                              |
| ttl         | None                                 |
| type        | A                                    |
| updated_at  | None                                 |
| version     | 1                                    |
| zone_id     | 01234567-89ab-cdef-0123-456789abcdef |
| zone_name   | domain.example.                      |
+-------------+--------------------------------------+

Updating record(set)s

$ openstack recordset set --description "Webserver FIP" --ttl 600 --record 123.45.67.88 domain.example. www.domain.example.
+-------------+--------------------------------------+
| Field       | Value                                |
+-------------+--------------------------------------+
| action      | UPDATE                               |
| created_at  | 2019-06-21T15:39:36.000000           |
| description | Webserver FIP                        |
| id          | 01234567-89ab-cdef-0123-456789abcdef |
| name        | www.domain.example.                  |
| project_id  | 0123456789abcdef0123456789abcdef     |
| records     | 123.45.67.88                         |
| status      | PENDING                              |
| ttl         | 600                                  |
| type        | A                                    |
| updated_at  | 2019-06-24T10:44:33.000000           |
| version     | 2                                    |
| zone_id     | 01234567-89ab-cdef-0123-456789abcdef |
| zone_name   | domain.example.                      |
+-------------+--------------------------------------+
$ openstack recordset set --no-description --no-ttl --record 123.45.67.89 domain.example. www.domain.example.
+-------------+--------------------------------------+
| Field       | Value                                |
+-------------+--------------------------------------+
| action      | UPDATE                               |
| created_at  | 2019-06-21T15:39:36.000000           |
| description | None                                 |
| id          | 01234567-89ab-cdef-0123-456789abcdef |
| name        | www.domain.example.                  |
| project_id  | 0123456789abcdef0123456789abcdef     |
| records     | 123.45.67.89                         |
| status      | PENDING                              |
| ttl         | None                                 |
| type        | A                                    |
| updated_at  | 2019-06-24T10:46:19.000000           |
| version     | 3                                    |
| zone_id     | 01234567-89ab-cdef-0123-456789abcdef |
| zone_name   | domain.example.                      |
+-------------+--------------------------------------+

Removing record(set)s

$ openstack recordset delete domain.example. www.domain.example.
+-------------+--------------------------------------+
| Field       | Value                                |
+-------------+--------------------------------------+
| action      | DELETE                               |
| created_at  | 2019-06-21T15:39:36.000000           |
| description | None                                 |
| id          | 01234567-89ab-cdef-0123-456789abcdef |
| name        | www.domain.example.                  |
| project_id  | 0123456789abcdef0123456789abcdef     |
| records     | 123.45.67.89                         |
| status      | PENDING                              |
| ttl         | None                                 |
| type        | A                                    |
| updated_at  | 2019-06-24T10:51:43.000000           |
| version     | 3                                    |
| zone_id     | 01234567-89ab-cdef-0123-456789abcdef |
| zone_name   | domain.example.                      |
+-------------+--------------------------------------+

Managing reverse DNS (PTR records) for floating IP addresses

If you need PTR records for your floating IP address, you achieve that by configuring your network such that forward A-records and reverse PTR-records are set up automatically for you. Please refer to the How-to guide on adding PTR records for an existing floating IP and to the Networking reference guide.

Import/Export

There is a feature to import/export standard DNS Master Zone Files. This feature is intended to facilitate moving your zones to and from SysEleven Stack. More information about this process can be found on the How to export and import DNS zones page.

Transfer

Zones can be transferred between different projects within SysEleven Stack. The description of this process can be found on the How to transfer a DNS zone from one project to another page.

Collisions

Each domain name can only be registered once within the SysEleven Stack. If a domain name is already taken you cannot register this domain or a subdomain within. You can, however, create subzones within your already registered zone and transfer them to other users. Creation of a zone does not require actual control over the domain, it is legitimate to prepare zones for future use, e.g. in preparation of the registration. If you have the feeling that a zone is blocked illegitimately by another user, please contact our support.