Self-Hosted Image Registry

Kots can be used to download and prepare an application to be installed onto a secured, airgapped Kubernetes cluster. When doing this, there are a few additional steps and configuration needed.

Docker Registry

To install an application into an airgapped network, you must have a Docker image registry that’s available inside the network. Kots will manage rewriting the application image names in all application manifests to read from the on-prem registry, and it will retag and push the images to the on-prem registry. When authenticating to the registry, credentials with push permissions are required.

A single Kots application expects to use a single “namespace” in the Docker image registry.

The namespace name can be any valid URL-safe string, supplied at installation time. Keep in mind that a registry typically expects the namespace to exist before any images can be pushed into it.

NOTE: ECR does not use namespaces.

Kots has been tested for compatibility with the following registries:

• Docker Hub
• Quay
• Amazon Elastic Container Registry (ECR)
• Google Container Registry (GCR)
• Harbor
• Sonatype Nexus