ybettan / image-composer Goto Github PK

As a first step we are going to move towards a single container image, built by the customer.
This image should be the same image applied to MCO by the user in case it was a day2 operation.

In the future, we can start creating "thin layers" which can be container images based on scratch that will only contain the "diff" from the base image a vendor will want. For example, an HW vendor can only publish a container based on scratch that will contain its kernel module. Those layers can then be "applied on top" of a base image such as FCOS/RHCOS/R4E to form a new container image.

One way to deal will conflicts between file changed in a "layer" and the base image used as a base for the layer can be prevented by adopting the .d convention.

coreos-assembler
RHEL image builder

https://coreos.github.io/rpm-ostree/compose-server/

This repo is currently targeting using the coreos-assembler in order to build a new RHCOS/FCOS/RHEL-for-edge ISO for every customer that requires a "flavored" ISO for his cluster installation.

For simplicity, from now on I will just refer to RHCOS but it should apply for FCOS/RHEL-for-edge as well.

On the other hand, the coreos-installer allows some ISO manipulations such as embedding an ignition into the ISO without the need to rebuild the whole RHCOS image each time a new "flavor" for the image is required.

Having some sub-commands in the coreos-installer to inject "container layers" to an ISO without rebuilding the ISO can be a big performance optimization.