feat(live): Add "/usr/bin/chroot" tool to the initrd

[lslezak]

Problem

• The /usr/bin/chroot tool is not included in the initrd image anymore (it was in the past, probably some change in dracut...)

Solution

• Explicitly include it in the dracut configuration

Usage

It can be used for editing the file in the root image before booting the system. We could include an editor like vim, joe or nano in the initrd but those tools are quite big. In most cases you can just use the editor from the root image itself, you just need a chroot command for that.

• Boot with rd.break=cleanup option
• When the dracut maintenance prompt appears just press Enter
• Then run chroot /sysroot (that's the place where the future root is mounted at this point)
• Run the editor from the root image simply by using vim ... command
• Exit chroot (Ctrl+D)
• Exit maintenance mode (Ctrl+D)
• The boot continues using the modified files

The initrd size increase is tiny (~30kB uncompressed) compared to adding a full editor.

Testing

• Tested manually