Setting up encrypted volumes with LUKS

From Alpine Linux

LUKS allows encrypting a partition and mapping it as a virtual block device, which can then be used as a normal partition. Guides for other Linux distributions should serve as a general references for installing Alpine onto a LUKS encrypted disk.

The following approaches are known to work:

There is no reason to assume more exotic setups would fail to work on Alpine.

mkinitfs and LUKS

For those familiar with setting up FDE on other Linux distributions, this section contains only Alpine-specific knowledge required is understanding mkinitfs.

First of all, the cryptsetup feature needs to be added to /etc/mkinitfs/mkinitfs.conf. Additionally, the following kernel parameters are required:

  • cryptroot kernel parameter should point to the encrypted block device.
  • root kernel parameter should point to the mapped block device (e.g.: the ext4/btrfs volume that is exposed once the encrypted partition is unlocked).
  • rootfstype: The filesystem type of the root partition (e.g.: btrfs).

See also