Automate Building your Own Atomic Host

Project Atomic hosts are built from standard RPM packages which have been composed into filesystem trees using rpm-ostree. This post provides method for automation of Building Atomic host (Creating new trees).

Requirements

• Fedora Atomic QCOW2 Image : Fedora-Atomic.
• Make sure that Ansible is installed on your system. Note that I am using Fedora-Workstation.

Process

Clone the Git repo on your working machine Build-Atomic-Host.

$ git clone https://github.com/trishnaguha/build-atomic-host.git
$ cd build-atomic-host

Create VM from the QCOW2 Image

The following creates VM from QCOW2 Image where username is atomic-user and password is atomic. Here atomic-nodein the instance name.

$ sudo sh create-vm.sh atomic-node /path/to/fedora-atomic25.qcow2
# For example: /var/lib/libvirt/images/Fedora-Atomic-25-20170131.0.x86_64.qcow2

Start HTTP Server

The tree is made available via web server. The following playbook creates directory structure, initializes OSTree repository and starts the HTTP server.

$ ansible-playbook httpserver.yml --ask-sudo-pass

Use ip addr to check IP Address of the HTTP server.

Give OSTree a name and add HTTP Server IP Address

Replace the variables given in vars/atomic.yml with OSTree name and HTTP Server IP Address.

For Instance:

# Variables for Atomic host
atomicname: my-atomic
httpserver: 192.168.122.1

Here my-atomic is OSTree name and 192.168.122.1 is HTTP Server IP Address.

Run Main Playbook

The following playbook installs requirements, starts HTTP Server, composes OSTree, performs SSH-setup and rebases on created Tree.

$ ansible-playbook main.yml --ask-sudo-pass

Check IP Address of the Atomic instance

The following command returns the IP Address of the running Atomic instance

$ sudo virsh domifaddr atomic-node

Reboot

Now SSH to the Atomic Host and reboot it so that it can reboot in to the created OSTree:

$ ssh atomic-user@<atomic-hostIP>
$ sudo systemctl reboot

Verify: SSH to the Atomic Host

Wait for 10 minutes, You may want to go for a Coffee now.

$ ssh atomic-user@192.168.122.221
[atomic-user@atomic-node ~]$ sudo rpm-ostree status
State: idle
Deployments:
● my-atomic:fedora-atomic/25/x86_64/docker-host
       Version: 25.1 (2017-02-07 05:34:46)
        Commit: 15b70198b8ec7fd54271f9672578544ff03d1f61df8d7f0fa262ff7519438eb6
        OSName: fedora-atomic

  fedora-atomic:fedora-atomic/25/x86_64/docker-host
       Version: 25.51 (2017-01-30 20:09:59)
        Commit: f294635a1dc62d9ae52151a5fa897085cac8eaa601c52e9a4bc376e9ecee11dd
        OSName: fedora-atomic

Now you have the Updated Tree.

Shout-Out for the following folks:

• Gerard Braad who mentored me for the project.
• Jonathon Lebon who demonstrated Building Atomic host workshop in DevConf.CZ, 2017 at Brno. His slides are here: jlebon-devconf-slides.

My future post will have customizing packages (includes addition/deletion) for OSTree.