simplek8s.yaml

The file simplek8s.yaml is the SimpleK8s cloud-init: a YAML document applied on first boot to create users, mount storage, write files, and configure the node. You can let nodectl install generate a minimal one, or write your own and pass it with -config.

Minimal example

Generate a SHA-512 password hash with:

$ openssl passwd -6 root
$6$6tbYaQIa9rENVsvf$bT1mdigoVGEtPmX0rrtgErBzCqCBcfb78KbufVULNiwJQvVbolMVRVVRJdzkJgL0PorDTrHgNanvEYqnW2xHI/

version: "1"

users:
  - name: root
    # Password will be `root`
    password_hash: $6$6tbYaQIa9rENVsvf$bT1mdigoVGEtPmX0rrtgErBzCqCBcfb78KbufVULNiwJQvVbolMVRVVRJdzkJgL0PorDTrHgNanvEYqnW2xHI/
    ssh_authorized_keys:
      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICOJHHXFdcBLMAviMAHgQvCuzpnLmzXxatIL6IUe7b6W salvador.joseluis@gmail.com

storage:
  mounts:
    - what: /dev/disk/by-label/var
      where: /var

Specifications

All fields marked in italic are optional.

  • version (string): Currently must be 1.
  • users (list of objects):
    • name (string): User name.
    • password_hash (string): Default is "x".
    • ssh_authorized_keys (list of string): Default is none.
    • uid (int): Default is next unused uid.
    • gid (int): Default is the same value of uid.
    • groups (list of string): Default is none.
    • system (boolean): UID default value will be more or equal than 1000 if it is false. Default is false.
    • gecos (string): User description. Default is empty.
  • groups (list of objects):
    • name (string): Group name.
    • gid (int): Group Id. Default is next unused gid.
    • system (boolean): GID default value will be more or equal than 1000 if it is false. Default is false.
  • storage (object):
    • mounts (list of objects):
      • what (string): Device or path.
      • where (string): Target mount point path.
      • type (string): Filesystem type. Default is "auto".
      • options (string): Comma-separated mount options in mount(8)/fstab style. Default is "defaults" (no-op). Known flags (ro, rw, nosuid, nodev, noexec, bind, rbind, relatime, …) become kernel mount flags; defaults is accepted and ignored; anything else (ex: discard, uid=1000, iocharset=utf8) is passed verbatim as filesystem data.
    • links (list of objects):
      • overwrite (boolean): Default is false.
      • path (string)
      • target (string)
      • owner (string): Default is the current process uid:gid.
      • hard (boolean): Default is false.
    • directories (list of objects):
      • overwrite (boolean): Default is false.
      • path (string)
      • owner (string): Default is the current process uid:gid.
      • permissions (string): Default is "0775".
    • files (list of objects):
      • overwrite (boolean): Default is false.
      • path (string)
      • encoding (string): Default is empty. If it is "b64" content will be decoded as Base64.
      • content (string): Default is empty.
      • owner (string): Default is the current running process uid:gid.
      • permissions (string): Default is "0664".

Full example

version: "1"

users:
  - name: root
    # Password will be `root`
    password_hash: $6$n2yzXErLUUm5/C38$PtFZeevgw7A5LlD7J8WZlElsIl6yfpse4F6MeVx0GhIHn9WdHkVePiyd2x/kQE2UeJit.tKPn/Yez0fvL9O0K.
    ssh_authorized_keys:
      - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICOJHHXFdcBLMAviMAHgQvCuzpnLmzXxatIL6IUe7b6W salvador.joseluis@gmail.com
    uid: 0
    gid: 0
    groups:
      - ops
    system: false
    gecos: Super User

groups:
  - name: ops
    gid: 1
    system: true

storage:
  mounts:
    - what: /dev/disk/by-label/var
      where: /var
      type: ext4
      options: defaults

    - what: /var/home
      where: /home
      type: none
      options: bind

    - what: 10.0.0.123:/storage
      where: /mnt/storage
      type: nfs4
      options: defaults

  links:
    - overwrite: false
      path: /etc/somedir
      target: /root/somedir
      owner: root:root
      hard: false

    - overwrite: true
      # Mask `/usr/lib/systemd/network/99-dhcp.network`
      path: /etc/systemd/network/99-dhcp.network
      target: /dev/null
      owner: root:root
      hard: false

  directories:
    - overwrite: false
      path: /root/somedir
      owner: root:root
      permissions: "0770"

    - overwrite: true # This flag will empty the `/root/will_empty_dir` directory
      path: /root/will_empty_dir
      owner: root:root
      permissions: "0775"

  files:
    - # An example file
      overwrite: false
      path: /root/somedir/somefile
      encoding: b64 # Base64-encoded content
      # `content` will be decoded as: Hello world
      content: SGVsbG8gd29ybGQK
      owner: root:root
      permissions: "0664"

    - # Add a global executable script
      overwrite: true
      path: /usr/local/bin/hello
      encoding:
      content: |
        #!/bin/sh
        echo "Hello world"
      owner: root:root
      permissions: "0775"

    - # Configure static network address
      overwrite: false
      path: /etc/systemd/network/50-wired.network
      encoding:
      content: |
        [Match]
        Name=en*

        [Network]
        Address=192.168.1.50/24
        Gateway=192.168.1.1
        DNS=192.168.1.1
        DNS=1.1.1.1
        DNS=8.8.8.8
      owner: root:root
      permissions: "0644"