- name: Replace fstab entries with gpt partlabel
  shell: |
    set -euo pipefail # strict mode

    INFO=$(blkid | grep "{{ item.1.name }}")
    BYPARTLABEL="/dev/disk/by-partlabel/{{ item.1.name }}"
    DEV=$(echo $INFO | perl -F: -lane 'print $F[0]')
    echo "*** BYPARTLABEL=${BYPARTLABEL}"
    echo "*** DEV=${DEV}"

    grep "${BYPARTLABEL}" /mnt/etc/fstab && {
      echo "OK=partlabel already in fstab"
    } || {

      # if partlabel exists and is a symlink
      [[ -h "${BYPARTLABEL}" ]] && {
        echo "*** ${BYPARTLABEL} exists"

        perl -i -ne '
          BEGIN { $changed=0; }

          if (s|^'"${DEV}"'|'"${BYPARTLABEL}"'|) {
            $changed=1;
          }

          print $_;

          END {
            if ($changed == 1) {
              print STDERR "CHANGED=partlabel changed in fstab\n";
            } else {
              print STDERR "OK\n";
            }
          }
        ' /mnt/etc/fstab

      } || {
        echo "Something went wrong.  ${BYPARTLABEL} does not exist or is not a symlink"
        exit 1
      }
    }

  args:
    executable: /bin/bash
  register: partlabels
  changed_when: ( 'CHANGED=partlabel' in partlabels.stderr )
  with_indexed_items: "{{ disk_partitions }}"
  when: ( disk_part_scheme == 'gpt' and fstab_defined_by == 'label' )