Flatcar Container Linux Development Container

This repository automatically builds a Docker container of the Flatcar Container Linux Development image.

The development image contains a more complete linux including a full compiler toolchain. It allows to modify, extend or build custom binaries, drivers or libraries for Flatcar Linux that are not included in the production image.

Here we automatically turn the raw developer image into a Docker container. It allows us to use the familiar Docker workflow. It is especially nice in combination with multi-stage Docker builds, which allows to create minimal transport images without the build chain overhead.

These images are intended to be used by Flatcar Forklift drivers

Kernel Sources

In addition to the "base" development container, we will also create a "sources" version, which extends the "base" image with kernel sources stored in /usr/src/linux. This provides developers with a starting-point for building kernel modules and drivers that are guaranteed to work with their Flatcar kernel.

Github Actions Configuration

The build is using a cron job that executes the build daily. It creates alpha, beta and stable images. It first pulls the current versions of each Flatcar release channel. Then it checks if the corresponding image already exists on Dockerhub. Only then rebuild the image.

This makes the build indempotent and avoids daily churn on Github Actions.

With the way Flatcar is promoting versions through the channels, this will usually only build new alpha versions. There's a maximum latency from release to availability of this Docker image.

Docker Images

Find the image on Docker Hub: https://hub.docker.com/r/mediadepot/flatcar-developer/

docker pull mediadepot/flatcar-developer:2605.9.0
docker pull mediadepot/flatcar-developer:2605.9.0-sources

References

• https://github.com/BugRoger/coreos-developer-docker