Thanks digrouz
Install ddclient into an Alpine Linux container
DDclient is a Perl client used to update dynamic DNS entries for accounts on Dynamic DNS Network Service Provider. It has the capability to update more than just dyndns and it can fetch your WAN-ipaddress in a few different ways.
https://sourceforge.net/p/ddclient/wiki/Home/
docker create --name=ddclient \
-v <path to ddclient.conf>:/etc/ddclient/ddclient.conf \
-v /etc/localtime:/etc/localtime:ro \
-e DOCKUID=<UID default:10007> \
-e DOCKGID=<GID default:10007> \
-e DOCKMAIL=<mail address> \
-e DOCKRELAY=<smtp relay> \
-e DOCKMAILDOMAIN=<originating mail domain> \
babim/ddclient
DYNUSER
DYNPASS
DOMAIN
DYNMX
DYNPROTOCOL
When you start the ddclient image, you can adjust the configuration of the ddclient instance by passing one or more environment variables on the docker run command line.
This variable is not mandatory and specifies the user id that will be set to run the application. It has default value 10007.
This variable is not mandatory and specifies the group id that will be set to run the application. It has default value 10007.
This variable is not mandatory and specifies the smtp relay that will be used to send email. Do not specify any if mail notifications are not required.
This variable is not mandatory and specifies the mail that has to be used to send email. Do not specify any if mail notifications are not required.
This variable is not mandatory and specifies the address where the mail appears to come from for user authentication. Do not specify any if mail notifications are not required.