How to run kubermatic in offline environments

Date: 2020-05-13

Create master cluster with k1

Configure your distribution to use a package mirror that provides the official docker and kubernetes packages. You can realize that with apt-mirror, artifactory, squid or many others
Integrate this in the image templates that will be used by k1 for the control plane and by machine controller for workers.
Populate the K1 config as usual, but include the following setting, which instructs k1 not the mess with the package sources:

systemPackages:
  configureRepositories: no

Execute kubeone install.

Kubermatic

Use either a docker registry that contains all the images kubermatic needs or mirror the docker hub repo, quay and gcr. Can be seperate logical registries or some subpaths of a single one.
Fetch the kubermatic-installer repo.
Edit the values.yaml and replace all the 50 image definitions with the ones that are specific to the registry. That sucks but there is not really a generic way to automate that.
Install kubermatic as usual