netbox

coredns-netbox-plugin

This plugin gets an A record from NetBox1. It uses the REST API of netxbox to ask for a an IP address of a hostname:

https://netbox.example.org/api/ipam/ip-addresses/?dns_name=example-vm-host

{
    "count": 1,
    "next": null,
    "previous": null,
    "results": [
        {
            "id": 426,
            "family": {
                "value": 4,
                "label": "IPv4"
            },
            "address": "192.168.1.101/25",
            "vrf": null,
            "tenant": null,
            "status": {
                "value": 1,
                "label": "Active"
            },
            "role": null,
            "interface": {
                "id": 452,
                "url": "https://netbox.example.org/api/virtualization/interfaces/452/",
                "device": null,
                "virtual_machine": {
                    "id": 10,
                    "url": "https://netbox.example.org/api/virtualization/virtual-machines/10/",
                    "name": "VM22"
                },
                "name": "ens12"
            },
            "nat_inside": null,
            "nat_outside": null,
            "dns_name": "vm22-jump-host",
            "description": "",
            "tags": [],
            "custom_fields": {
                "dhcp_route": null
            },
            "created": "2020-03-04",
            "last_updated": "2020-03-04T16:57:07.375937Z"
        }
    ]
}

Usage

To activate the plugin you need to compile CoreDNS with the plugin added to plugin.cfg

netbox:github.com/oz123/coredns-netbox-plugin

Then add it to Corefile:

. {
   netbox {
      token <YOU-NETBOX-API-TOKEN>
      url <https://netbox.example.org>
      localCacheDuration <The duration to keep each entry locally before querying netbox again. Use go `time.Duration` notation>
   }
}

The config parameters are mandatory.

Developing locally

You can test the plugin functionallity with CoreDNS by adding the following to go.mod in the source code directory of coredns.

replace github.com/oz123/coredns-netbox-plugin => <path-to-you-local-copy>/coredns-netbox-plugin

Testing against a remote instance of netbox is possible with SSH port forwarding:

Host YourHost
   Hostname 10.0.0.91
   ProxyJump YourJumpHost
   LocalForward 18443 192.168.1.128:8443

Credits

This plugin is heavily based on the code of the redis-plugin for CoreDNS.