search for systemd units in .wants or .requires dirs that are regular files and convert them back to symlinks

fix-systemd-symlinks.sh

#!/bin/sh

set -ex

for i in $(find /etc/systemd/system/ -maxdepth 2 -mindepth 1 -type d); do
  if ! grep -qP '\.wants|\.requires' <<<"$i"; then
    continue
  fi

  for f in $(find $i -type f); do
    #echo $f is a regular file
    unit_name=$(basename $f)
    if [ -f "/etc/systemd/system/$unit_name" ]; then
      #echo $unit_name is in /etc/systemd/system
      ln -sf /etc/systemd/system/$unit_name $f
    elif [ -f "/usr/lib/systemd/system/$unit_name" ]; then
      #echo $unit_name is in /usr/lib/systemd/system
      ln -sf /usr/lib/systemd/system/$unit_name $f
    fi
  done
done

# explicit fix for [email protected]. Instantiated units will not have an exact match from the symlink
# to the canonical unit file, but in our case we don't make use of instantiated services aside from
# the [email protected] instance
ln -sf /usr/lib/systemd/system/[email protected] /etc/systemd/system/getty.target.wants/[email protected]