feat(dracut): add option to disable automatic guessing of output file

This patch allows forcing the input of the file path for the generated initramfs
image (disabling automatic guessing of the location) using a new configuration
option `force_output_file=yes`.

dracut.sh

@@ -946,6 +946,13 @@ for f in $(dropindirs_sort ".conf" "$confdir" "$dracutbasedir/dracut.conf.d"); d
     [[ -e $f ]] && . "$f"
 done
 
+# check if automatic guessing of the output file is disabled.
+if [[ $force_output_file == "yes" && -z $outfile ]]; then
+    printf "%s\n" "dracut[F]: dracut is configured with force_output_file=yes" >&2
+    printf "%s\n" "dracut[F]: so it is required to specify the file path of the generated initramfs image." >&2
+    exit 1
+fi
+
 # regenerate_all shouldn't be set in conf files
 regenerate_all=$regenerate_all_l
 if [[ $parallel_l == "yes" ]]; then

man/dracut.conf.5.asc

@@ -320,6 +320,13 @@ Logging levels:
    If set to _yes_, try to execute tasks in parallel (currently only supported
    for _--regenerate-all_).
 
+*force_output_file=*"__{yes|no}__"::
+   If set to _yes_, require to specify a file path for the generated initramfs
+   image, disabling automatic guessing of the location (default=no).
+   In some complex scenarios, distribution owners may want to disable the logic
+   for guessing the location of the output file, to prevent users from calling
+   dracut directly to create useless initramfs that won't be used at boot.
+
 Files
 -----
 _/etc/dracut.conf_::