Configuration specifications

Butane Configs must conform to a specific variant and version of the Butane schema, specified with the variant and version fields in the configuration.

See the Upgrading Configs page for instructions to update a configuration to the latest specification.

Stable specification versions

We recommend that you always use the latest stable specification for your operating system to benefit from new features and bug fixes. The following stable specification versions are currently supported in Butane:

Experimental specification versions

Do not use experimental specifications for anything beyond development and testing as they are subject to change without warning or announcement. The following experimental specification versions are currently available in Butane:

Butane specifications and Ignition specifications

Each version of the Butane specification corresponds to a version of the Ignition specification:

Butane variantButane versionIgnition spec
fcos1.0.03.0.0
fcos1.1.03.1.0
fcos1.2.03.2.0
fcos1.3.03.2.0
fcos1.4.03.3.0
fcos1.5.03.4.0
fcos1.6.0-experimental3.5.0-experimental
flatcar1.0.03.3.0
flatcar1.1.03.4.0
flatcar1.2.0-experimental3.5.0-experimental
openshift4.8.03.2.0
openshift4.9.03.2.0
openshift4.10.03.2.0
openshift4.11.03.2.0
openshift4.12.03.2.0
openshift4.13.03.2.0
openshift4.14.03.4.0
openshift4.15.03.4.0
openshift4.16.03.4.0
openshift4.17.03.4.0
openshift4.18.0-experimental3.5.0-experimental
r4e1.0.03.3.0
r4e1.1.03.4.0
r4e1.2.0-experimental3.5.0-experimental
fiot1.0.03.4.0
fiot1.1.0-experimental3.5.0-experimental