LazyLibrarian

[SamGreenwood]

Quoting the docs page:

LazyLibrarian is a program to follow authors and grab metadata for all your digital reading needs.

The current source repo is https://gitlab.com/LazyLibrarian/LazyLibrarian.git

Releases(Tags) are at https://gitlab.com/LazyLibrarian/LazyLibrarian/tags

Bug reports at https://gitlab.com/LazyLibrarian/LazyLibrarian/issues

And finally Reddit https://www.reddit.com/r/LazyLibrarian/

EDIT:

Licence: GNU GPL v3.0
Docker: Yes - https://sasquatters.com/lazylibrarian-docker/ http://sasquatters.com/lazylibrarian-configuration/

Docker packages
LinuxServer : https://hub.docker.com/r/linuxserver/lazylibrarian/
The docker package includes ghostscript for magazine cover generation and calibredb (via optional variable)
LinuxServer docker is multi-arch and works on X86_64, armhf and aarch64 (calibredb only available on X86_64)
The dockers can be upgraded using the lazylibrarian internal upgrade mechanism