This is just a homework project using 
Server listens on [::]:14514.
The address of the graph database.
This env var is optional. If set, TLS negotiation will be attempted.
The username of the graph database.
The password of the graph database.
Check the documention for details.
Check the documention for details.
When build the image, specify build args with --build-args.
This value will be passed to sed as a script when modifying /etc/apk/repositories.