# Architecture

Sealer has two top module: Image Module & Cluster Module

The Image module using Kubefile and build context as input, and build a Sealer Image that contains all the dependencies.

The Cluster module implements the desired state of cluster through Clusterfile and Sealer Image.

# Image module

# Build Engine

  • parser : parse Kubefile into Dockerfile.
  • builder : execute each build instruction and save its asset.
  • committer : commit Sealer Image to image engine.

# Image Engine

Provides a common interface to the Sealer Image, such as list,delete,mount,inspect and the interaction with the local disk and the remote registry hub.

# Cluster module

  • common user interface: provides a common user interface to launch Sealer Image through sealer CLI or Clusterfile.
  • image preprocessor: implement content distribution and modification through config or env render for the Sealer Image.
  • cluster runtime: cluster installer implementation, like using kubeadm to install or upgrade k8s cluster.
  • plugin : implements the maintenance of hosts and the modification of the cluster at different process phase.