tinkerbell/charts: introduce `showcase` chart

[rpardini]

tinkerbell/charts: introduce showcase chart

• showcase is a chart that, based on values.yaml dictionaries:
  • generates Tinkerbell CRs (Hardware/Template/Workflow) for both standard (UEFI) & exotic (supported by Armbian) devices
  • generates download/process jobs for multiple Hook flavors (see https://github.com/tinkerbell/hook/pull/205)
  • generates download/process jobs for a few OS images (Ubuntu Cloud Images, Armbian, etc)
  • should be independent of how one deployed Tinkerbell itself (stack chart, individual components, etc)
• A few features:
  • validates values.yaml for common mistakes; arch must match, etc.
  • validates & handles rootDisk differences (re-invents "formatPartition()" a bit)
  • avoids re-downloading Hooks and Images that are already on disk, even if Job re-runs
  • allows easy way to use
    • custom Hooks
    • custom Kernel cmdline parameters at both the Hook & device level
      • for example acpi=off at Hook level and console=ttyS0 at board level
    • custom OS images for deployment
    • reboot or kexec to finish deployment
    • different partition numbers for OS image's rootfs (some images have ESP, some have a separate /boot, etc)
    • control if growpart and/or ssh/user setup is done during provisioning or not
    • conversion of OS images (qemu-to-raw-gzip and xz-to-gz)
  • has a "merge" mechanism with a common way to set parameters like net gateway, UEFI, etc (also easy to override per-device)
  • default values have everything enabled: false thus showcase should produce nothing by default.
    • Hooks & Images can be forced enabled: true in values.yaml, or
      • enabled: true Devices automatically enable their Hook & Image
• Probably missing:
  • More validations
  • Currently pointing to my Tinkerbell Actions, which I haven't PR'ed yet
• How to use:
  • Clone it, edit the values.yaml to your liking, and deploy.

Signed-off-by: Ricardo Pardini [email protected]