Fedora 22’s Atomic Host dropped most of packages for the web-based server UI, cockpit, from its system tree in favor of a containerized deployment approach. Matt Micene blogged about running cockpit-in-a-container with systemd, but people have expressed interest in learning how to start this container automatically, with cloud-init.
Create and Run Applications in Linux Containers
Create your application using Docker containers. Deploy and manage containerized applications on a proven, trusted platform.
Project Atomic introduces Atomic App — an implementation of the Nulecule specification, which lets you manage multi-container applications and orchestration metadata as easily as you manage RPMs.
With Atomic App, you can use existing containers as building blocks for your new application product or project.
Databases, web servers, and other common components are vital parts of applications and services. Utilizing existing containers to provide these core infrastructure components lets you focus more on building the stuff that matters and less time packaging and setting up the common plumbing required.
Nulecule /NOO-le-kyul/ (noun)
Nulecule is a made-up word meaning "the mother of all atomic articles". Sounds like "molecule". But different.
Also a specification for applications composed from multiple containers. Check it out on Github below, or read through the Getting Started -guide if you want to know more.
Based on proven technology either from Red Hat Enterprise Linux or the CentOS and Fedora projects, Atomic Host is a lightweight, immutable platform, designed with the sole purpose of running containerized applications.
To balance the need between long-term stability and new features, we are providing different releases of Atomic Host for you to choose from.
Kubernetes, the open source orchestration system for Docker containers, is a fast-moving project that can be somewhat complicated to install and configure, especially if you’re just getting started with it.
Fortunately, the project maintains some really well-done getting started guides, the simplest of which steps you through running Kubernetes, in Docker containers, on a single host.
The up-and-running part of the walkthrough amounts to issuing just three docker run commands:
# docker run --net=host -d gcr.io/google_containers/etcd:2.0.9 /usr/local/bin/etcd --addr=127.0.0.1:4001 --bind-addr=0.0.0.0:4001 --data-dir=/var/etcd/data # docker run --net=host -d -v /var/run/docker.sock:/var/run/docker.sock gcr.io/google_containers/hyperkube:v0.21.2 /hyperkube kubelet --api_servers=http://localhost:8080 --v=2 --address=0.0.0.0 --enable_server --hostname_override=127.0.0.1 --config=/etc/kubernetes/manifests # docker run -d --net=host --privileged gcr.io/google_containers/hyperkube:v0.21.2 /hyperkube proxy --master=http://127.0.0.1:8080 --v=2
Now, this isn’t as simple as rattling off a single command from memory, but we can’t have everything…
…or can we?
Through the magic of a couple tools we’ve been working on here at Project Atomic, we can get up and running with the upstream kubernetes project’s containerized install method using a single command like this:
# atomic run jasonbrooks/kubernetes-atomicapp
I often get bug reports from users asking
why can’t I use `docker` as a non root user, by default?
Docker has the ability to change the group ownership of the /run/docker.socket to have group permission of 660, with the
group ownership the docker group. This would allow users added to the docker group to be able to run docker containers without having to execute
su to become root. Sounds great…
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Video above from Kubernetes 1.0 Launch event at OSCON
In the above video, I attempted to put Red Hat’s container efforts into a bit of context, especially with respect to our history of Linux platform development. Having now watched the above video (they forced me to watch!) I thought it would be good to expound on what I discussed in the video.
Admit it, you’ve read one of the umpteen millions of articles breathlessly talking about the new Docker/Kubernetes/Flannel/CoreOS/whatever hotness and thought to yourself,
Wow, is this stuff overhyped. There is some truth to that knee-jerk reaction, and the buzzworthiness of all things container-related should give one pause -
It’s turt^H^H^H^Hcontainers all the way down!
Testing Nulecule on Debian
Unless you’ve recently returned from a sabbatical year in a remote monastery with no internet, you know that Containers have arrived, and it’s a whole new world.
I’ll save you five minutes of reading, and 90 minutes of watching Disney’s Alladin and assume you know about containers. If not, take a look at Docker, rkt and the Open Container Project. For bonus points, watch How Docker Didn’t Invent Containers from the First Docker Meetup in my adopted hometown of Brno, Czech Republic. When you’re done singing the fantastic Disney songs, come back. I’ll wait.
Ready to try Atomic?