CoreOS rkt is a modular container engine with three stages of execution. Stage1 is responsible for creating the execution environment for the contained applications.
Stage1s come in the form of ACI images, and they can be user-provided. For example, the following option allows the user to specify a different stage1 from the command line:
rkt --stage1-path=/path/to/stage1-xen.aci
This project aims at providing a new stage1 based on the Xen hypervisor. Each pod (a small set of contained applications) is run in a separated Xen virtual machine. On x86 PV and PVH virtual machines are used, depending on the availability of hardware virtualization support.
Note: stage1-xen is under active development. We encourage you to try stage1-xen and give us your feedback. However unlike upstream Xen Project, we are still in preview phase. So please do not expect long term support or backward compatibility as yet.
See BUILDING.md for all the details. Make sure to have all the dependencies installed, see DEPENDENCIES. Xen needs to be at least version 4.9. Then, execute build.sh. The output is the file stage1-xen.aci, which is the stage1 ACI image. stage1-xen.aci does not contain any Xen binaries itself, it relies on xl being available on the host.
You can use stage1-xen by passing the appropriate --stage1-path option to rkt:
rkt run sha512-b1dcf7bfa88f --interactive --insecure-options=image --stage1-path=/home/sstabellini/stage1-xen.aci