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IT teams can derive a number of benefits from a lightweight operating system designed specifically for containers. But first, admins must decide which OS matches their organization's container strategy, based on factors such as security and performance optimization.
Bottlerocket is a free Linux-based container OS designed by AWS. Because it includes only the bare minimum, in terms of software components necessary to run containers, IT teams can optimize resource use and reduce both operational burdens and costs associated with container deployments.
Here, we'll look at other benefits, and potential limitations, of Bottlerocket, as well as how it compares to another lightweight OS, Alpine Linux.
Benefits of Bottlerocket
Bottlerocket provides a more consistent host deployment system than Ubuntu, Red Hat or other standard Linux platforms. Every deployed instance will be the same as the last. It also comes with a promise of a long-term stable release for whatever version is in use.
What sets Bottlerocket apart is the lack of required setup and management. Many administrators will recognize the multiple updates, patches and application installs necessary to manage a host OS. Each one represents an area of potential issues -- whether they're upstream issues or just a bad update.
Bottlerocket only runs software as containers and does not have a package manager. This, according to AWS, means admins can apply Bottlerocket updates and rollbacks in a single step, which minimizes the risk of errors. Upgrades are done at an all-or-nothing level: Either everything works, or everything is rolled back. Bottlerocket also uses partitions, which are a useful fallback when necessary.
Bottlerocket hosts are designed to be disposable. There are no "running updates" -- an upgrade is a switch from the old version to the new version, where an orchestrator downloads and deploys the new image.
Bottlerocket is a minimal layer that is deployed, run and retired as appropriate. The deployment is designed so IT teams can use existing orchestration tools within AWS, such as Amazon Elastic Kubernetes Service, to manage it.
It also creates a much more secure environment. Bottlerocket has fewer installed applications, which saves resources and reduces potential security issues. There is a well-defined set of APIs through which management can be done securely.
A big part of the Docker philosophy is that the API abstraction layer decouples container images from the underlying implementation -- Bottlerocket is an extension of this philosophy.
Bottlerocket has no third-party plugins, no registries and no third-party apps.
Overall, Bottlerocket is designed to be very hands-off in terms of maintenance, which should please developers.
Each major release of Bottlerocket is supported by Amazon for at least three years.
Where Bottlerocket falls short
While Bottlerocket is free to download and use, everything about it is highly tuned to the AWS platform. This limits the tool to AWS environments, and it is uncertain if that will change.
All the tools around it are based on tight integration to AWS. The code and configuration underlying the Bottlerocket system is on GitHub.
Bottlerocket is designed for large, highly automated, highly dynamic environments. Small environments won't gain much from Bottlerocket due to the retooling and testing involved.
Bottlerocket is available in most regions, but not all, and not in AWS governmental environments. Some of the more advanced items on Amazon Machine Image instances, such as GPU-enabled functionality, are currently incompatible with Bottlerocket.
Bottlerocket vs. Alpine Linux
Both Bottlerocket and Alpine Linux are super small in terms of both physical distribution size and resources consumed. Alpine Linux, for example, will install and run in under 32 MB of RAM. Those saved resources can be used to produce more containers.
At the same time, Alpine Linux is a very simplistic implementation of Linux and, while highly configurable when needed, it doesn't have the complexities of service management that come with most other Linux distributions. That means less to go wrong, fewer items to secure and fewer resources consumed. Bottlerocket works on a similar principle.
The biggest difference between the two OSes is flexibility. Alpine Linux is designed to work in any Linux-based container environment, while Bottlerocket is restricted to usage on AWS.