lib/generate.sh: Fix EROFS file UIDs and use compression (#176)

The EROFS mkfs invocation missed the --all-root flag to make sure that
the files are owned by root regardless of the current UID during image
generation. By default EROFS also doesn't compress and we can use LZ4 as
a lightweight compresson option (LZMA would also work). Add the
--all-root flag and the compression flag to mkfs.erofs to use UID 0 and
compress the contents.

Author: pothos

lib/generate.sh

@@ -109,7 +109,8 @@ function _generate_sysext() {
   announce "Creating extension image '${fname}' and generating SHA256SUM"
   case "$format" in
     btrfs)
-      mkfs.btrfs --mixed -m single -d single --shrink --rootdir "${basedir}" "${fname}"
+      # Note: We didn't chown to root:root, meaning that the file ownership is left as is
+      mkfs.btrfs --mixed -m single -d single --shrink --compress zstd --rootdir "${basedir}" "${fname}"
       ;;
     ext2|ext4)
       truncate -s "${ext_fs_size}" "${fname}"
@@ -120,7 +121,9 @@ function _generate_sysext() {
       mksquashfs "${basedir}" "${fname}" -all-root -noappend -xattrs-exclude '^btrfs.'
       ;;
     erofs)
-      mkfs.erofs "${fname}" "${basedir}"
+      # Compression recommendations from https://erofs.docs.kernel.org/en/latest/mkfs.html
+      # and forcing a zero UUID for reproducibility (maybe we could also hash the name and version)
+      mkfs.erofs -zlz4hc,12 -C65536 -Efragments,ztailpacking -Uclear --all-root "${fname}" "${basedir}"
       ;;
 
   esac

wasmcloud.sysext/create.sh

@@ -33,6 +33,7 @@ function populate_sysext_root() {
 
   mkdir -p "${sysextroot}/usr/bin"
   cp -a "wasmcloud-${rel_arch}-unknown-linux-musl" "${sysextroot}/usr/bin/wasmcloud"
+  chmod +x "${sysextroot}/usr/bin/wasmcloud"
   cp -a "nats-server-${nats}-linux-${go_arch}/nats-server" "${sysextroot}/usr/bin/"
 }
 # --