How to download and install the latest version of ddclient
DDclient is a perl script to update accounts for Dynamic DNS Service Provider. 
ddclient is available in testing/edge repository.
In order to use it, you need first to enable that repository by adding to /etc/apk/repositories:
# apk update
# apk add ddclient
A sample configuration file is installed by default in
Rename it as
/etc/ddclient/ddclient.conf and modify it according to your needs.
Then, start ddclient as usual:
# rc-service ddclient start
If you want/need, configure the service to start automatically on boot:
# rc-update add ddclient default