GitLab

permit to use a postprocessed nbdroot

When using a postprocessed nbdroot like:
actions:
- deploy:
    to: downloads
    postprocess:
      docker:
        image: debian:buster
        steps:
         - mkdir rootfs
         - cd rootfs && tar xpf ../rootfs*
         - mke2fs -d . -m 0 -t ext2 ../rootfs.ext2 1600M
    images:
      stage3:
        url: http://xxx/root.tar.xz
        compression: xz

- deploy:
    protocols:
      lava-xnbd:
      - action: nbd-deploy
        request: set_port
    to: nbd
    nbdroot:
      url: downloads://rootfs.ext2

...LAVA fail with a keyerror on nbdroot.

Problem #1:
This is due that only downloaded files(via class DownloadHandler) ran the spetial "nbdroot register":
        if "lava-xnbd" in self.parameters and nbdroot:
            self.parameters["lava-xnbd"]["nbdroot"] = nbdroot
The solution is to register nbdroot also for pre-downloaded files. (via PreDownloadedAction)

Problem #2:
But PreDownloadedAction only know full path to the nbdroot, so we need
to add a check in XnbdAction() since "normal nbdroot" are stored via
relative path.

Problem #3:
The last problem is that when using a postprocessed NBD root,
NBDSERVERIP and NBDSERVERPORT are not replaced.
So the "use NBD" check in BootloaderCommandOverlay need to be replaced.