homeserverdns: Dynamic DNS updater for home servers

homeserverdns monitors the IPv6 addresses (using the ip tool from iproute2). When it detects a change, it updates the A and AAAA records for a set of domains (and subdomains).

So far it has modules for these domain provider APIs:

• gandi.net LiveDNS API
• http.net DNS API (untested)
• dyn.com API (untested)

Dependencies

• curl
• miniupnpc (optional, see the Configuration section)

Installation

TBD

Configuration

The configuration options are described in homeserverdns.cfg. First a protocol has to be defined, e.g.

protocol=gandi

For authentication at the domain provider, an authentication token has to be geven. Some protocols require a user name and an API address, too.

auth_key=g5Hdsfkj5J49li8HH3jfhsJp
user= 		# not required for gandi
api_address=	# not required for gandi

Now the domains (and subdomains) we want to update A and AAAA records for have to be defined.

domains=mydomain.com sub.mydomain.com

By default UPNP is used for detecting the server's public IPv4 address. So we should check if upnp works and returns the correct IPv4 address.

$ upnpc -s
upnpc : miniupnpc library test client, version 1.9.                                       
 (c) 2005-2016 Thomas Bernard.                                                            
Go to http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/                          
for more information.                                                                     
List of UPNP devices found on the network :                                               
 desc: http://10.0.0.1:5000/rootDesc.xml                                                  
 st: urn:schemas-upnp-org:device:InternetGatewayDevice:1                                  
                                                                                          
Found valid IGD : http://10.0.0.1:5000/ctl/IPConn                                         
Local LAN ip address : 10.0.0.23
Connection Type : IP_Routed
Status : Connected, uptime=530079s, LastConnectionError : ERROR_NONE
  Time started : Tue Oct 30 08:57:09 2018
MaxBitRateDown : 10000000 bps (10.0 Mbps)   MaxBitRateUp 1000000 bps (1.0 Mbps)
ExternalIPAddress = 85.98.82.44
Bytes:   Sent: 402633281        Recv: 816703147
Packets: Sent:  3408416 Recv:  4216845

If we don't get a value for ExternalIPAddress, we should check our router and firewall settings. If UPNP does not work for us (e.g. in case the server is behind a Carrier Grade NAT), we can define our own method for looking up our public IPv4 address using the public_ip4_hook config option, e.g.

public_ip4_hook=curl -s -4 https://ipecho.net/plain