add devbyid dependency

[automated-distro-installer] / devbyid

diff --git a/devbyid b/devbyid
new file mode 100755 (executable)
index 0000000..ecf4988
--- /dev/null
+++ b/devbyid
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+# input eg: /dev/sda1 or /dev/sda
+# output: /dev/disk/by-id/model+serial, or if no link exists, the same as input
+
+short_dev=$1 # i.e.
+
+# devices are identified by model+serial num,
+# and wwn. model+serial gives me more info, so use that.
+shopt -s extglob
+for id in /dev/disk/by-id/!(wwn*); do
+    [[ -e $id ]] || break # if we matched nothing
+    if [[ $(readlink -f $id) == "$short_dev" ]]; then
+        printf '%s\n' "$id"
+        exit
+    fi
+done
+# a vm may not have a by-id link.
+printf '%s\n' "$short_dev"