NAME

bootc-container-compute-composefs-digest - Output the bootable composefs digest for a directory

SYNOPSIS

bootc container compute-composefs-digest [OPTIONS] [PATH]

DESCRIPTION

Output the bootable composefs digest for a directory

This is the digest that bootc container ukify embeds in the kernel command line of a UKI. It is a 128-character SHA-512 hex string that identifies the filesystem contents. Most image builds should use bootc-container-ukify(8), which computes it internally; this command is useful for scripting and debugging outside of that flow.

The digest depends on the EROFS format; see --erofs-version. It must be run against a separate mount of the root filesystem, not the running root.

OPTIONS

PATH

Path to the filesystem root

--write-dumpfile-to=WRITE_DUMPFILE_TO

Additionally generate a dumpfile for the preferred digest, written to the target path

--erofs-version=EROFS_VERSION

EROFS format version to use when computing the composefs digest

Possible values:
- v1
- v2

Default: v1

EXAMPLES

Compute the digest of a root filesystem mounted at /target:

bootc container compute-composefs-digest /target

Also write a composefs dumpfile, to compare against another build:

bootc container compute-composefs-digest --write-dumpfile-to /tmp/rootfs.dump /target

VERSION

The Linux Foundation® (TLF) has registered trademarks and uses trademarks. For a list of TLF trademarks, see Trademark Usage.

Keyboard shortcuts