ospfip

Name

ospfip - resolve host names to tagged OpenStack Floatig IP's.

Description

The ospfip plugin queries an OpenStack Floating IP API and resolves hostnames found in predefined tags on Floating IP's.

Currently the plugin supports both A and AAAA (including wildcards) and PTR records (excluding wildcards).

Note: This is intended for test/development environments. Use with care.

How it authenticates

This plugin uses gophercloud under the hood to work with the OpenStack API and relies on it for authentication using either a clouds.yaml file or sourced openrc file.

To use the clouds.yaml file, place it at ~/.config/openstack/clouds.yaml. To use the openrc file, its values need to be set for the coredns process.

How it works

The plugin queries the OpenStack API for Floating IP's with a coredns:plugin:ospfip tag. Next the plugin extracts the to-be-resolved hostname from an additional coredns:plugin:ospfip:<hostname> tag.

Only the first encountered coredns:plugin:ospfip:<hostname> pair on a Floating IP is taken into account.

Syntax

ospfip [ZONES...] {
    ttl SECONDS
    refresh DURATION
}

• ZONES zones it should be authoritative for.
• ttl change the DNS TTL of the records generated. The default is 3600 seconds (1 hour).
• refresh the period between calls to the OpenStack Floating IP API to retrieve tagged Floating IP's. Valid formatting examples are "300ms", "1.5h" or "2h45m". See Go's time. package.

Examples

. {
    ospfip
}

In short, this:

$ openstack floating ip show <ID> -c tags -c floating_ip_address
+---------------------+---------------------------------------------------------------------------------+
| Field               | Value                                                                           |
+---------------------+---------------------------------------------------------------------------------+
| floating_ip_address | 10.0.0.1                                                                        |
| tags                | ['coredns:plugin:ospfip', 'coredns:plugin:ospfip:*.example.net']                |
+---------------------+---------------------------------------------------------------------------------+

resolves to (when running the coredns binary locally):

$ dig +noall +answer @0 q.example.net
q.example.net. 3600 IN   A       10.0.0.1

Limit the zones (origins) taken into account:

example.net. {
    ospfip
      refresh 2m
      ttl 5400
}