scriptbox/alpine-initramfs-dropbear

Alpine Initramfs Dropbear

This script took a huge references from:

• https://github.com/Deeplerg/fork-alpine-initramfs-dropbear

• https://github.com/mk-f/alpine-initramfs-dropbear

• https://gitlab.alpinelinux.org/alpine/mkinitfs/-/blob/master/initramfs-init.in

This script is modified from alpine/mkinitfs - initramfs-init.in

significant changes:

• Add dropbear

• After unlocked, kill all remainings dropbear and nlplug-findfs process, so no struck process reached the system.

• optional support IPv6 unlock

Fileinfo:

alpine-initramfs-base : normal alpine initramfs file which the code is based on

initramfs-dropbear : normal dropbear version

initramfs-dropbear-ipv6: dropbear with IPv6 support

*.patch : patch file version of the code

Install

Please install dropbear before continuing

1. copy dropbear/unlock_disk to /etc/dropbear/unlock_disk
   • Also Make sure /etc/dropbear/unlock_disk is executable! else dropbear will exit with "failed child"W
2. copy authorized_keys to /etc/dropbear/authorized_keys
3. copy features.d to /etc/mkinitfs/features.d
   • If using IPv6 mode, don't forget to also include features.d from alpine-initramfs-ipv6 folder.

Note:

• if you're using Deeplerg/mk-f scripts before don't forget to change unlock_disk as i modified that one too.
• If you're using grub make sure to install syslinux and possibly checkout /etc/default/grub and commented CMDLINE that's conflicted with update-extlinux like GRUB_CMDLINE_LINUX_DEFAULT and default_kernel_opts after that grub-mkconfig -o /boot/grub/grub.cfg

/etc/mkinitfs.conf

features="ata base ide scsi usb virtio ext4 cryptsetup keymap dropbear network"

• features+= dropbear network

• add ip if using in ipv6 mode

/etc/update-extlinux.conf

modules=sd-mod,usb-storage,ext4,ata_piix,virtio_net,e1000e,virtio_pci

• if network is not working (/sys/class/net/*/address not found etc.) try adding e1000e or virtio_net virtio_pci

default_kernel_opts="cryptroot=UUID=xxx cryptdm=root quiet rootfstype=ext4 dropbear=<dropbear_port> ip=<ip> ip6=<ip6>"

• ip= can be both static and dhcp(if supported) ip=<ip>::<gw>:<mask>::<interface> ip=dhcp

• ip6= only static is supported ip6=client-ip/gateway-ip/interface/dns1/dns2

• ip and ip6 is not compatible with each others! only use one.

update-extlinux

mkinitfs -i path/to/initramfs-dropbear <Kernel Version(from /lib/modules) incase in emergency CD>