# Arch Linux with LUKS and btrfs on a hetzner server (DRAFT)
This guide should show you how to set up an System with the following specifications on an hetzner server:
* Arch Linux
* btrfs
* LUKS
* mdraid
* dmcrypt

It adapts the following instruction:
* https://code.trafficking.agency/arch-linux-remote-unlock-root-volume-with-mdraid-and-dmcrypt.html
## Guide
### Preparing the Filesystems
```bash
# stop syncronisation before
# partition the discs
parted /dev/sda --align=opt --script mklabel gpt mkpart primary 0% 1GiB mkpart primary 1GiB 100%
parted /dev/sdb --align=opt --script mklabel gpt mkpart primary 0% 1GiB mkpart primary 1GiB 100%
# Modified because of https://askubuntu.com/questions/84538/trouble-creating-3tb-ext4-partition-due-to-msdos-partition-table-imposed-error
#reboot
```


```bash
# creating the filesystems, actually only /dev/sda1 is needed
mkfs.ext4 -L boot /dev/sda1
mkfs.ext4 -L boot /dev/sdb1

# creating the raid
mdadm --create --verbose --level=10 --metadata=1.2 --chunk=512 --raid-devices=2 --layout=f2 /dev/md0 /dev/sda2 /dev/sdb2

# and creating the dmcrypt "container"
cryptsetup -y -v luksFormat /dev/md0
cryptsetup luksOpen /dev/md0 root

# finally create the root filesystem
mkfs.ext4 -v -L root -m 0.01 -b 4096 -E stride=128,stripe-width=256 /dev/mapper/root
```
### Preparing for Arch
```bash
mkdir /arch
cd /arch
# download arch bootstrap disc, please choose the correct version
curl -O http://archlinux.mirrors.ovh.net/archlinux/iso/2020.04.01/archlinux-bootstrap-2020.04.01-x86_64.tar.gz
tar xvfz archlinux-bootstrap-2020.04.01-x86_64.tar.gz
```

Edit /arch/root.x86_64/etc/pacman.d/mirrorlist and choose a mirror
```bash
nano /arch/root.x86_64/etc/pacman.d/mirrorlist
```
https://gist.github.com/neonb88/5ba848f1aef21ab67c7a4ff28e6d2ea3
Just comment CheckSpace in /arch/root.x86_64/etc/pacman.conf
Chroot into the bootstrap environment
```bash
/arch/root.x86_64/bin/arch-chroot /arch/root.x86_64/
```
### More preparations

```bash
# mount the soon-to-be root-volume
mount /dev/mapper/root /mnt/

# and boot-volume
mkdir /mnt/boot
mount /dev/sda1 /mnt/boot
#https://unix.stackexchange.com/questions/490418/i-cant-make-a-grub-config
#mount --bind /proc /mnt/proc
#mount --bind /dev /mnt/dev
#mount --bind /sys /mnt/sys
#mount --bind /run /mnt/run

# initialize the pacman keychain this takes a long time do something from a second terminal, like dd if=/dev/sda of=/dev/tty7
pacman-key --init
## check out which of the following orders make sense
pacman-key --populate archlinux
pacman-key --refresh-keys
```
Finally, bootstrap Arch onto the root-volume...
```bash
pacstrap /mnt base base-devel intel-ucode
```

And bootstrap mdadmin.conf (md configuration) and fstab
```bash
pacman -Syyu mdadm # Added druing writing of instruction
mdadm --detail --scan >> /etc/mdadm.conf
genfstab -p /mnt > /mnt/etc/fstab
```

Chroot into the new Arch installation
```bash
arch-chroot /mnt/
```

Setup hostname and locales
```bash
echo test > /etc/hostname

echo LANG=en_US.UTF-8 > /etc/locale.conf
echo LC_COLLATE=C >> /etc/locale.conf
echo LANGUAGE=en_US >> /etc/locale.conf

ln -sf /usr/share/zoneinfo/Europe/Berlin /etc/localtime
```

Edit locale.gen according to your locale, don't forget en_US.UTF-8 or else some applications might complain.
```bash
pacman-key --populate archlinux
pacman -Syyu nano
nano /etc/locale.gen

locale-gen
```
### Setup early ssh with tinyssh and netconf
```bash
# some dependencies
# exit?
# dmraid here?
pacman -S sudo mkinitcpio mkinitcpio-nfs-utils tinyssh mkinitcpio-netconf mkinitcpio-tinyssh mkinitcpio-utils #ucspi-tcp
cd /tmp
```
Install mkinitcpio-netconf skipped because its in pacman.
Install ucspi-tcp
```bash
curl -O https://aur.archlinux.org/cgit/aur.git/snapshot/ucspi-tcp.tar.gz
tar xf ucspi-tcp.tar.gz
chown -R nobody:nobody ucspi-tcp
cd ucspi-tcp
sudo -u nobody makepkg

pacman -U ucspi-tcp-0.88-8-x86_64.pkg.tar.xz

cd ..
```
Skipped nstall mkinitcpio-tinyssh skipped because its in pacman.
Skipped nstall mkinitcpio-utils skipped because its in pacman.

Edit /etc/mkinitcpio.conf and add ***mdadm_udev netconf tinyssh encryptssh*** before filesystems should look something like this
```bash
HOOKS="base udev autodetect modconf block mdadm_udev netconf tinyssh encryptssh filesystems keyboard fsck"
```
Rebuild the initramfs
```bash
pacman -S linux
mkinitcpio -p linux
```

### Install and configure GRUB
```bash
#exit?
pacman -S grub
```
Edit /etc/default/grub and tell the Kernel about the cryptdevice and the mdraid, and netconf that we want dhcp
```bash
GRUB_CMDLINE_LINUX="cryptdevice=/dev/md0:root ip=dhcp md=0,/dev/sda2,/dev/sdb2"
```

Generate the grub config
```bash
grub-mkconfig -o /boot/grub/grub.cfg
```

Install Grub to /dev/sda
```bash
grub-install /dev/sda
```
## Guide
### 1. Configure and Install Image
#### 1.1
Login to Hetzner Rescue System
```bash
ssh root@your_server_ip
```
#### 1.2
Create the autosetup by executing

```bash
nano /autosetup
```

and saving the following content into this file:

```bash
##  Hetzner Online GmbH - installimage - config

DRIVE1 /dev/sda
DRIVE2 /dev/sdb

##  SOFTWARE RAID:
## activate software RAID?  < 0 | 1 >
SWRAID 1

## Choose the level for the software RAID < 0 | 1 | 10 >
SWRAIDLEVEL 1

##  BOOTLOADER:
BOOTLOADER grub

##  HOSTNAME:
HOSTNAME hetzner-arch-luks
#Adapt the hostname to your needs

##  PARTITIONS / FILESYSTEMS:
PART /boot  btrfs     512M
PART lvm    vg0       all
LV vg0   swap   swap     swap         8G
LV vg0   root   /        btrfs        10G

##  OPERATING SYSTEM IMAGE:
IMAGE /root/.oldroot/nfs/install/../images/archlinux-latest-64-minimal.tar.gz
```
#### 1.3
Afterwards install the image by executing the following command:

```bash
installimage
```
#### 1.4
When the setup finished restart the server via
```bash
reboot
```

### 2. Setup System
#### 2.1
Login to your server:

```bash
ssh-keygen -f "$HOME/.ssh/known_hosts" -R your_server_ip #revokes old ssh_host
ssh root@your_server_ip
```
#### 2.2
Update the system:
```bash
pacman -Syyu
```
#### 2.3
Install basic administration software:
```bash
pacman -Syyu nano
```

#### 3. Prepare System for Unlocking via SSH
#### 3.1 Execute the following script
```bash
# Install software
pacman -Syyu busybox mkinitcpio-dropbear mkinitcpio-utils mkinitcpio-netconf
#Copy ssh-key
cp -v ~/.ssh/authorized_keys /etc/dropbear/root_key
```
#### 3.2
Replace the following line in **/etc/mkinitcpio.conf**
```
HOOKS=(base udev autodetect modconf block mdadm_udev lvm2 filesystems keyboard fsck)
```
with
```
HOOKS=(netconf dropbear encryptssh base udev autodetect modconf block mdadm_udev lvm2 filesystems keyboard fsck)
```

### 4. Activate Encryption
#### 4.1
Activate the rescue system https://robot.your-server.de/server
#### 4.2
Afterwards reboot the system by entering:

```bash
reboot
```
#### 4.3
Login to the rescue system:
```bash
ssh-keygen -f "$HOME/.ssh/known_hosts" -R your_server_ip #revokes old ssh_host
ssh root@your_server_ip
```

#### 4.4
Mount the "system" by:
```bash
vgscan -v
vgchange -a y
mount /dev/mapper/vg0-root /mnt
```
#### 4.5
Copy "system":
```bash
# Resync unterbrechen
echo 0 >/proc/sys/dev/raid/speed_limit_max
mkdir /oldroot
cp -va /mnt/. /oldroot/.
# Resync fortsetzen
echo 200000 >/proc/sys/dev/raid/speed_limit_max
```
#### 4.6
Unmount the "system" by:
```bash
umount /mnt
```

#### 4.7
Delete unencrypted LVM-Volume-Group by executing:
```bash
vgremove vg0
```

#### 4.8
Check drive state:
```bash
cat /proc/mdstat
```
#### 4.9
Encrypt MD1 by executing:
```bash
cryptsetup --cipher aes-xts-plain64 --key-size 256 --hash sha256 --iter-time=10000 luksFormat /dev/md1
cryptsetup luksOpen /dev/md1 cryptroot
pvcreate /dev/mapper/cryptroot
vgcreate vg0 /dev/mapper/cryptroot
lvcreate -n swap -L8G vg0
lvcreate -n root -L10G vg0
mkfs.btrfs /dev/vg0/root
mkswap /dev/vg0/swap
```

#### 4.10
Mount encrypted :
```bash
mount /dev/vg0/root /mnt
```

#### 4.12
Copy "system":
```bash
# Resync unterbrechen
echo 0 >/proc/sys/dev/raid/speed_limit_max
cp -av /oldroot/. /mnt/.
# Resync fortsetzen
echo 200000 >/proc/sys/dev/raid/speed_limit_max
```

#### 4.13
Integrate finale installation:
```bash
mount /dev/md0 /mnt/boot
mount --bind /dev /mnt/dev
mount --bind /sys /mnt/sys
mount --bind /proc /mnt/proc
chroot /mnt
```

#### 4.14
```bash
echo "cryptroot /dev/md1 none luks" >> /etc/crypttab
```

# I think here the mess starts....
#### 4.15
rewrite initramfs ***?assume this should be right???***
```bash
mkinitcpio
mkinitcpio -p linux
```
Missing **initramfs neu schreiben** **GRUB neu schreiben**

ssh-keygen -b 4096 -t rsa -m PEM -f /etc/ssh/ssh_host_rsa_key
dropbearconvert openssh dropbear /etc/ssh/ssh_host_rsa_key /etc/dropbear/dropbear_rsa_host_key
* https://github.com/random-archer/mkinitcpio-systemd-tool/issues/21
* https://github.com/random-archer/mkinitcpio-systemd-tool/issues/17
* https://bbs.archlinux.org/viewtopic.php?id=250512

from point 4 on I have questions:
https://wiki.archlinux.org/index.php/Dm-crypt/Specialties#chkboot

check this one also out:
* https://blog.simonszu.de/set-up-luks-on-a-physical-hetzner-server-with-debian/ -> specially the part about dropbear configuration and ssh keys

https://gist.github.com/HardenedArray/31915e3d73a4ae45adc0efa9ba458b07

https://code.trafficking.agency/arch-linux-remote-unlock-root-volume-with-mdraid-and-dmcrypt.html

#### 4.15
```bash
exit
umount /mnt/boot /mnt/proc /mnt/sys /mnt/dev
umount /mnt
sync

#Neustart
reboot


```

## Sources
The code is adapted from the following guides:

* http://daemons-point.com/blog/2019/10/20/hetzner-verschluesselt/
* https://www.howtoforge.com/using-the-btrfs-filesystem-with-raid1-with-ubuntu-12.10-on-a-hetzner-server
* https://wiki.archlinux.org/index.php/Dm-crypt/Specialties#Remote_unlocking_(hooks:_netconf,_dropbear,_tinyssh,_ppp)