Docker will today release LinuxKit, an open-source toolbox for building fine-tuned Linux-based operating systems that run in containers.
No, it's not replacing Alpine. Docker uses the minimalist Alpine Linux distribution as the foundation of its official container images, and will continue to do so in future, we're told. Alpine is seen as an ideal all-purpose generic base for running heavy-lifting software like Redis and Nginx within containers. You can also switch Alpine for Debian, if you wish.
This newfangled LinuxKit, on the other hand, is for crafting a customized and optimized Linux subsystem that sits between the containerized application and the system host. LinuxKit is just like Docker's other open-source container toolkits – such as InfraKit and VPNkit – in this respect. It's an underlying component that can be swapped out or tweaked as you wish for particular environments and tasks.
This means you can optimize LinuxKit images for specific hardware platforms and host operating systems with just the drivers and other dependencies you need, and nothing more, rather than use a full-fat generic base. The toolkit basically tries to help you create your own slimline containerized operating system as painlessly as possible. The starting size of a LinuxKit image is 35MB, we're told.
The toolkit works with Docker's containerd, and it was produced with the help of the Linux Foundation, ARM, Intel, Hewlett Packard Enterprise, and Microsoft. Their input allows LinuxKit-built images to be tuned for their specific systems and hardware, and we assume these tech giants are using LinuxKit containers for their own purposes in various forms.
For what it's worth, Docker uses the kit to build the environments for its desktop clients and its Cloud Enterprise Edition.
The toolbox is not for everyone: we reckon the vast majority of folks will stick to Alpine or Debian-based images. Only those who need super-slim optimized setups will consider LinuxKit. Its use is not mandatory – it's there to save you drowning yourself in alcohol to numb the agony of devising your own tiny Linux operating system.
LinuxKit will be unveiled at DockerCon 2017 in Austin, Texas, today, along with Moby – which is a new push by Docker to encourage collaboration on future ideas and features in the world of containerization. Essentially, it looks as though Docker's reorganized its open-source repositories.
By the time you read this, there will be more technical details about LinuxKit over on the Docker website. ®