ansible-daemonset-container-linux

Exploration of using Ansible on-top of Kubernetes for configuring Container Linux hosts.

Theory of operation

Ansible is installed into a container image and then connects to the host via a bind mount to root and the chroot connection option connection module. This works without any RPC!

Ansible gets its configuration from site.yml and which is loaded into a configmap and placed inside of the Ansible container pod at /etc/ansible.

Background

Ansible might be desirable on Kubernetes for a number of reasons:

• Leverages existing software and modules in the ecosystem
• Ansible's DSL is simple enough to map from ignition config or equivalent used for first boot
• Debugging tools exist for Ansible include check and diff functionality
• Could be used for other non-automated cluster maintenance by customers like sysctl
  • Related field request

This was tested on Tectonic 1.7.9 cluster.

Building

Requires docker configured for docker build

./build.sh

Usage

Edit site.yml as needed to add different functionality as you wish from Ansible

The deploy script will create a config map, and run Ansible.

./deploy.sh

Future work

• Create script to convert ignition configs into ansible �
• Use base container from hyperkube or something
• Pin ansible version via hash
• Bootstrap module fetches images from container image instead of web
• Setup container image to CI/CD instead of Brandon's workstation