> For futureproofing it, perhaps make a Docker container of it
You can't (directly) put an OS in a Docker container. Docker is an application container technology, not an OS virtualisation technology. Apps inside Docker run in user mode under the Linux (or less commonly, Windows) kernel.
What you can do, is put an emulator in Docker, and put the OS in the emulator image. However, if your OS runs on a common platform (e.g x86 or x86-64), there is probably not much value to creating a Docker container vs just serving up the VM (such as a disk image or OVA file) for use with QEMU or VirtualBox or whatever.
If you are dealing with a more obscure platform, it can make more sense to package the image and emulator together into a Docker container. For example, I put the 1970s vintage IBM mainframe operating system MVS 3.8J [0] in a Docker container. I think that makes more sense because it requires a less common emulator (Hercules as opposed to QEMU or whatever), and Hercules needs to be configured with a specific configuration to make it work.
I think "machine preservation via emulation" may need to be a thing. Supposedly there's thousands of science papers, for example, whose supporting code may no longer trivially run...
You can't (directly) put an OS in a Docker container. Docker is an application container technology, not an OS virtualisation technology. Apps inside Docker run in user mode under the Linux (or less commonly, Windows) kernel.
What you can do, is put an emulator in Docker, and put the OS in the emulator image. However, if your OS runs on a common platform (e.g x86 or x86-64), there is probably not much value to creating a Docker container vs just serving up the VM (such as a disk image or OVA file) for use with QEMU or VirtualBox or whatever.
If you are dealing with a more obscure platform, it can make more sense to package the image and emulator together into a Docker container. For example, I put the 1970s vintage IBM mainframe operating system MVS 3.8J [0] in a Docker container. I think that makes more sense because it requires a less common emulator (Hercules as opposed to QEMU or whatever), and Hercules needs to be configured with a specific configuration to make it work.
[0] https://hub.docker.com/r/skissane/mvs38j