Harvester: Adding a custom systemd unit using oem cloud-config

create-config.yaml

# Adding the following config stanza to all the Harvester create|join configs will create
# a custom cloud-config `/oem/95_user.yaml` during the (early) "initramfs" cloud-init stage
# of the initial Harvester boot.
# This cloud-config will be executed on each system (re-)boot during the (late) "boot" cloud-init
# stage and may contain any cloud-init directives supported by the cOS Toolkit:
# See https://rancher.github.io/elemental-toolkit/docs/reference/cloud_init/
# Additionally, any files added to the /oem folder in day-2 are persistent and won’t be overwritten
# during Harvester upgrades.

  write_files:
  - content: |
      name: "User Config"
      stages:
        boot:
          - name: "Drop unit file"
            files:
            - path: /etc/systemd/system/update-ca.service
                content: |
                [Unit]
                Description=Foo
                (...)
              permissions: 0644
              owner: root
              group: root
          - name: "Enable unit"
            systemctl:
              enable:
              - update-ca
    owner: root
    path: '/oem/95_user.yaml'
    permissions: '0600'