Bottlerocket is a Linux based operating system built for running containers, developed by Amazon Web Services (AWS). It follows many of the design principles of CoreOS (automated, atomic updates, minimal distribution, admin "tools" container), so on a conceptual level is familiar. However, some of the implementation details are different (e.g. use of TUF rather than Omaha for updates). Also, it only ships with a variant specifically targeted to run as a base OS for Amazon's Elastic Kubernetes Service (EKS). Variants for other use cases and environments are on the roadmap.
Migration from CoreOS Container Linux
There is no documented migration path from CoreOS Container Linux to Bottlerocket.
Production Readiness and Support
Bottlerocket is a relatively new project, announced in March 2020 with general availability slated for later in 2020.
Bottlerocket is supported by Amazon through AWS support plans, when running in AWS environment.