k0s

k0s Runtime Design

basefs

.
├── amd64
│   ├── bin
│   │   ├── k0s
│   │   ├── kubectl
│   │   ├── nerdctl
│   │   └── seautil
│   ├── images
│   │   └── registry.tar.gz
│   └── Metadata
├── imageList
├── Kubefile
└── rootfs
    ├── etc
    │   ├── dump-config.toml
    │   └── registry.yml
    └── scripts
        ├── containerd.sh
        ├── init-registry.sh
        └── init.sh

introduce

We define the k0s runtime has 5 phases to install/scale/reset the cluster.

basefs contains binary、shell script、config file and image. See more about sealerio/basefs

Runtime before filesystem lead cluster install through execute k0s command.

• Init
  • When sealer leads to cluster install first, init phase copy rootfs/bin to /usr/bin in init.sh script
  • create bootstrap config /etc/k0s/k0s.yaml to lead controller init
  • generate k0s join token /etc/k0s/worker-token and /etc/k0s/controller-token, also private registry cert
  • init controller node
  • fetch config for ~/.kube/config to manage the cluster.
• Join
  • Join phase prepare the registry certs, and use k0s join to scale up the cluster.
• Delete
  • Delete is same as join, but it recycles anything installed by join phase.
• Reset
  • Reset through k0s to remove this cluster and remove anything about the cluster generated by sealer.
• Upgrade
  • Coming for soon!