[RFE] add erofs tools

[ader1990]

Current situation

containerd is improving on its erofs support, see:
containerd/containerd#11340

Currently, Flatcar's containerd has a failure log message related to erofs, as it is missing the erofs tools:

Mar 23 10:17:42 localhost containerd[1843]: time="2026-03-23T10:17:42.153586265Z" level=info msg="skip loading plugin" error="failed to check mkfs.erofs availability: failed to run mkfs.erofs --help: exec: \"mkfs.erofs\": executable file not found in $PATH: skip plugin" id=io.containerd.differ.v1.erofs type=io.containerd.differ.v1

Impact

No full erofs support in Flatcar's containerd.

Ideal future situation

Have full support.

Implementation options

Add https://packages.gentoo.org/packages/sys-fs/erofs-utils to Flatcar.

Additional information

[ Please Add any information that does not fit into any of the above sections here ]

[ader1990]

With PR flatcar/scripts#3854:

journalctl |grep -i erofs
Mar 25 12:37:10 localhost kernel: erofs: (device dm-1): mounted with root inode @ nid 54.
Mar 25 12:37:10 localhost kernel: erofs: (device dm-1): mounted with root inode @ nid 54.
Mar 25 12:37:11 localhost kernel: erofs: (device dm-2): mounted with root inode @ nid 54.
Mar 25 12:37:12 localhost kernel: erofs: (device dm-2): mounted with root inode @ nid 54.
Mar 25 12:37:12 localhost kernel: erofs: (device dm-2): mounted with root inode @ nid 36.
Mar 25 12:37:13 localhost kernel: erofs: (device dm-2): mounted with root inode @ nid 37.
Mar 25 12:37:13 localhost kernel: erofs: (device dm-2): mounted with root inode @ nid 37.
Mar 25 12:37:14 localhost kernel: erofs: (device dm-2): mounted with root inode @ nid 36.
Mar 25 12:37:14 localhost kernel: erofs: (device dm-3): mounted with root inode @ nid 37.
Mar 25 12:37:15 localhost kernel: erofs: (device dm-4): mounted with root inode @ nid 37.
Mar 25 12:37:21 localhost kernel: erofs: (device dm-5): mounted with root inode @ nid 54.
Mar 25 12:37:22 localhost kernel: erofs: (device dm-5): mounted with root inode @ nid 54.
Mar 25 12:37:22 localhost kernel: erofs: (device dm-5): mounted with root inode @ nid 37.
Mar 25 12:37:22 localhost kernel: erofs: (device dm-5): mounted with root inode @ nid 36.
Mar 25 12:37:23 localhost kernel: erofs: (device dm-5): mounted with root inode @ nid 37.
Mar 25 12:37:23 localhost kernel: erofs: (device dm-5): mounted with root inode @ nid 37.
Mar 25 12:37:23 localhost kernel: erofs: (device dm-6): mounted with root inode @ nid 36.
Mar 25 12:37:24 localhost kernel: erofs: (device dm-7): mounted with root inode @ nid 37.
Mar 25 12:37:27 localhost containerd[1859]: time="2026-03-25T12:37:27.280256810Z" level=info msg="loading plugin" id=io.containerd.mount-handler.v1.erofs type=io.containerd.mount-handler.v1
Mar 25 12:37:27 localhost containerd[1859]: time="2026-03-25T12:37:27.280720530Z" level=info msg="loading plugin" id=io.containerd.snapshotter.v1.erofs type=io.containerd.snapshotter.v1
Mar 25 12:37:27 localhost containerd[1859]: time="2026-03-25T12:37:27.319468779Z" level=info msg="loading plugin" id=io.containerd.differ.v1.erofs type=io.containerd.differ.v1