raid-array: Fix md re-add automation

Recent versions of `mdadm` stopped accepting `/dev/disk/by-id` symlinks
as the MD device:

> mdadm: Value "/dev/disk/by-id/md-name-backup5" cannot be set as devname. Reason: Cannot be started from '/' or '<'.

To work around this, we need a script to resolve the symlink and pass
the real block device name.

raid-array.yml

@@ -29,14 +29,35 @@
     tags:
     - mdadm
     - mdadm-create
+  - name: ensure md-auto-readd script is installed
+    copy:
+      content: |+
+        #!/bin/sh
+
+        main() {
+            md_dev=$(readlink -e /dev/disk/by-id/md-name-"$2")
+            if [ -z "${md_dev}" ]; then
+                printf 'Could not find block device for MD raid %s\n' "$2" >&2
+                exit 1
+            fi
+            exec mdadm --re-add "${md_dev}" "$1"
+        }
+
+        main "$@" 2>&1 | logger
+      dest: /usr/local/libexec/md-auto-readd
+      owner: root
+      group: root
+      mode: u=rwx,go=rx
+    tags:
+    - script
   - name: ensure raid auto re-add udev rule exists
     copy:
       content: >+
-        ENV{ID_FS_LABEL}=="{{ md_name }}",
+        ACTION=="add",
         ENV{ID_FS_TYPE}=="linux_raid_member",
         ENV{ID_FS_USAGE}=="raid",
-        RUN+="/usr/sbin/mdadm --re-add /dev/disk/by-id/md-name-{{ md_name }} $devnode"
-      dest: /etc/udev/rules.d/80-{{ md_name }}.rules
+        RUN+="/usr/local/libexec/md-auto-readd $devnode $env{ID_FS_LABEL}"
+      dest: /etc/udev/rules.d/80-md-auto-readd.rules
       mode: u=rw,go=r
       owner: root
       group: root