The issue

The plugin.yml allows specifying a list of libraries that are downloaded from maven central on server startup. As Maven Central has recently started to rate limit entire networks which download too many artifacts, this has caused issues with loading some plugins: https://mclo.gs/MeuePJU

The Proposed solution

At Aternos, we would like to host a mirror of Maven Central for our servers, to reduce the load on their repositories. Unfortunately, it appears that Spigot does not yet offer any way to use such a mirror.

We would like a way to configure a mirror that will be used for artifacts on Maven Central, e.g., as an option in the spigot.yml. The aether library used to download these libraries has an option to provide these mirrors (see setMirrorSelector in DefaultRepositorySystemSession).