- reformat to common format on dscheck_*
  - you missed some (
  - i personally like functions that "get out early".
    if ! something; then
       return $DS_NOT_FOUND
    fi
    ... further checks ...

- I fixed a syntax / logic error in azure
- not sure that DS_CHECKS need to or should be ordered in local then net
  just not sure here.
- need to not use 'cat' in 'found'
- 'found': not sure why the 'touch', i suspect that is debug ? or it is
   required by cloud-init i bet in order to read the confd...

- has_fs_with_label should cache result... we want to only call blkid
  once ever ideally.
  - we probably have to run with -c /dev/null (cachefile)

- both has_cdrom and block_dev_with_label rely on /dev/ symlinks
  that is probably udev racey as you found.
  dscheck_ovf relies on that.
  block_dev_with_label also curremtly does.