add documentation

README.md

@@ -0,0 +1,65 @@
+# homeserverdns: Dynamic DNS updater for home servers
+homeserverdns monitors the IPv6 addresses (using the ip tool from [iproute2](https://wiki.linuxfoundation.org/networking/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](https://doc.livedns.gandi.net/)
+- [http.net DNS API](https://www.http.net/docs/api/) (untested)
+- [dyn.com API](https://help.dyn.com/remote-access-api/perform-update/) (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
+``

homeserverdns.cfg

@@ -1,5 +1,5 @@
 # Protocol name, may be left empty when using a custom update_hook.
-# The default update_hook supports: gandi, dyndns
+# The default update_hook supports: gandi, httpnet, dyndns
 protocol=
 
 # The command to be called to determine our public IP address. By default UPNP