Project Atomic is now sunset

The Atomic Host platform is now replaced by CoreOS. Users of Atomic Host are encouraged to join the CoreOS community on the Fedora CoreOS communication channels.

The documentation contained below and throughout this site has been retained for historical purposes, but can no longer be guaranteed to be accurate.

Project News

Fedora 27 Atomic Host March 15th Release

Fedora Atomic Host Version: 27.100 is available.

  • Commit(x86_64): 326f62b93a5cc836c97d31e73a71b6b6b6955c0f225f7651b52a693718e6aa91
  • Commit(aarch64): ba2aa19d99466c53e614651f014c8b97ae1940f87885b7c7dfed1fb62ae91567
  • Commit(ppc64le): ca0ea3a6e15b6270aefe3c7b55ffbee3c8bd27707fd6d979cc66b39fc18fa5f4

Read More »

Update Kernel arguments on Atomic Host

Users or adminstrators may want to change kernel arguments of Atomic Host for various reasons. Previously, it was hard for the users due to many of the steps involved, and the harmful consequences that can occur if users accidentally make a mistake in the changing process.

In this post, I want to introduce a command (rpm-ostree ex kargs) that allows users to change kernel arguments on Atomic Host. This command simplifies the process of changing kernel arguments. This command also lies beneath rpm-ostree, and because of that, it benefits from many of the cool features from rpm-ostree. One of them is rpm-ostree rollback, which can allow users to undo their old changes they do not want.

Note: This command is still experimental, so if you have seen any unexpected behavior happening, please report an issue to rpm-ostree. This post also requires some knowledge of Atomic Host and rpm-ostree, please bear that in mind when reading this.

Let’s demonstrate some of the options that can be done with this command!

Read More »

The Many Ways to Build an OCI Image without Docker

When containers initially made their big splash into the industry via Docker, users were almost required to use the docker CLI and daemon to create and manage their container images. But a lot has happened since then and now it is easier than ever to create a container image without using docker at all, since the Docker image format has been standardized as the OCI Image format.

In this post, we’ll review some of the ways you can create and manage your container images without ever having to start the docker daemon.

Read More »

How does Atomic run system containers without Docker Daemon?


In 2016, we started to Containerize the Kubernetes stack, that is to ship all the components as containers as you can see here. But some of those containers like etcd and flanneld must be started before Docker daemon because etcd is the cluster state store, and flanneld is the cluster network overlay (SDN).

In this blog post we are going to demonstrate how to use the same components used by Project Atomic in the so called system containers that is to run the containers without a Docker daemon, namely: skopeo, ostree, and an OCI runtime like runc or bubble wraps and its OCI wrapper.

Read More »