Everything about Swift is open-source (integration into Xcode is not). If I recall, 5.0.1 is the recent Linux bug fix version that is being led by @johannesweiss. I think there is a Docker image already built, if not, I think it is being built and submitted.
I think the version of Swift you are referencing in your post is Swift 5.1, not 5.0.1. The 5.1 release is/will be in the Swift repository and is/will be an official release of the language and environment, so there will be images built for the supported environments. I think Docker images for the supported versions of Linux are built as part of the release process now, but, I'm not sure. Not much of a Linux user.