Amazon Web Services (AWS) today launched a Linux-based container operating system designed specifically to host containers. The move comes as one long-time option is set to exit the scene.

The AWS Bottlerocket OS is designed as a basic platform to run inside of a container. Jeff Barr, chief evangelist for AWS, noted in a blog post that it “includes only the packages that are needed” and “integrates with existing container orchestrators.” Think Kubernetes.

It also supports Docker images that conform to the Open Container Initiative (OCI) image format, which are both common container platforms and should help initial development. Its initial preview release is focused on AWS’ EKS managed Kubernetes service. Barr added that more than 80% of all cloud-based containers are running in AWS.

Bottlerocket also downloads a full filesystem image and reboots into it rather than using a package manager that updates individual pieces of software. It also relies on two identical sets of partitions that allow it to automatically roll back to a previous build if a reboot fails.

“This removes opportunities for conflicts and breakage, and makes it easier for you to apply fleet-wide updates with confidence using orchestrators such as EKS,” Barr explained.

For security, Bottlerocket relies on a primarily read-only file system that is “integrity-checked at boot time.” It also does not rely on secure shell (SSH), though one can be installed as part of a separate admin container for troubleshooting.

The platform adheres to the general notion of a container operating system, which is to strip away all unnecessary OS features to facilitate quicker DevOps productivity.

Container-specific operating systems allow multiple containers to share the same OS without the need for a hypervisor to oversee each container. This reduces operational overhead and is different from traditional virtual machines (VMs), which typically call for each VM to have a separate OS and hypervisor.

A container-specific OS also has a smaller footprint, which provides for a smaller attack surface and makes it easier to create save points when updating systems.

The Bottlerocket launch comes on the heels of Red Hat phasing out support for its CoreOS Container Linux platform that it acquired as part of its $250 million CoreOS purchase in early 2018. The product is still available, but most of the CoreOS features have been merged into Red Hat’s Kubernetes-based OpenShift platform.

CoreOS for years has been one of the more popular container operating systems. However, that space has since garnered new entrants like Rancher Labs’ RancherOS, Canonical’s Ubuntu Core, and VMware’s Photon OS platforms. These provide a much smaller footprint, stripping away features that are not required in a container environment.