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improved dedicated hetzner server install script

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Ingolf Wagner 2021-12-27 12:31:48 +01:00
parent 760c68c783
commit 32f5eb6524
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1 changed files with 63 additions and 118 deletions
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171
scripts/hetzner-dedicated-wipe-and-install-nixos.sh
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@ -21,15 +21,37 @@
# * We set a custom `configuration.nix` so that we can connect to the machine afterwards,
# inspired by https://nixos.wiki/wiki/Install_NixOS_on_Hetzner_Online
# * This server has 2 HDDs.
# We put everything on RAID1.
# Storage scheme: `partitions -> RAID -> LVM -> ext4`.
# We encrypt all hard drives and put an LVM on it the main logical volume is mirrored
# Storage scheme: `partitions -> dm-crypt -> LVM -> ext4`.
#
# ┌────────┐ ┌────────┐
# │ sda1 │ ◄──── grub ─────► │ sdb1 │
# ├────────┤ ├────────┤
# │ sda2 │ ◄──── /boot ─────► │ sdb2 │
# ├────────┤ ├────────┤
# │ sda3 ├───┐ ┌───┤ sdb3 │
# └────────┘ │ │ └────────┘
# │ │
# ┌────────────▼┐ ┌▼────────────┐
# │ a_encrypted │ │ b_encrypted │
# └────────┬────┘ └────┬────────┘
# │ ┌──────────┐ │
# └─────► LVM vg ◄─────┘
# └────┬─────┘
# │
# ┌─────────────▼──────────────┐
# │ root (mirrored/raid1) │
# ├────────────────────────────┤
# │ nextcloud (mirrored/raid1) │
# ├────────────────────────────┤
# │ media (raid0) │
# └────────────────────────────┘
# * A root user with empty password is created, so that you can just login
# as root and press enter when using the Hetzner spider KVM.
# Of course that empty-password login isn't exposed to the Internet.
# Change the password afterwards to avoid anyone with physical access
# being able to login without any authentication.
# * The script reboots at the end.
# * does not use uefi (check if you can : efibootmgr)
# Notes https://mazzo.li/posts/hetzner-zfs.html
@ -44,6 +66,9 @@ set -x
# Inspect existing disks
lsblk
# Cleanup
# -------
# Undo existing setups to allow running the script multiple times to iterate on it.
# We allow these operations to fail for the case the script runs the first time.
set +e
@ -54,42 +79,23 @@ cryptsetup close a_encrypted
cryptsetup close b_encrypted
set -e
# Stop all mdadm arrays that the boot may have activated.
mdadm --stop --scan
# Prevent mdadm from auto-assembling arrays.
# Otherwise, as soon as we create the partition tables below, it will try to
# re-assemple a previous RAID if any remaining RAID signatures are present,
# before we even get the chance to wipe them.
# From:
# https://unix.stackexchange.com/questions/166688/prevent-debian-from-auto-assembling-raid-at-boot/504035#504035
# We use `>` because the file may already contain some detected RAID arrays,
# which would take precedence over our `<ignore>`.
echo 'AUTO -all
ARRAY <ignore> UUID=00000000:00000000:00000000:00000000' > /etc/mdadm/mdadm.conf
# Create partition tables (--script to not ask)
#parted --script /dev/sda mklabel gpt
#parted --script /dev/sdb mklabel gpt
#parted /dev/sda -- mklabel gpt
#parted /dev/sda -- mkpart ESP fat32 1MiB 512MiB
#parted /dev/sda -- set 1 boot on
#parted /dev/sda -- mkpart primary 512MiB 100%
# ---------------------------------------------
format() {
parted -s "$1" -- mklabel gpt
parted --script "$1" -- mklabel gpt
parted -s "$1" -- mkpart 'BIOS-boot-partition' 1MB 2MB set 1 bios_grub on
#parted -s "$1" -- mkpart 'boot' 2MB 512MiB
#parted -s "$1" -- mkpart ESP fat32 2MB 512MiB
parted -s "$1" -- mkpart ESP fat32 2MB 512MiB set 2 boot on
parted --script "$1" -- mkpart 'BIOS-boot-partition' 1MB 2MB set 1 bios_grub on
#parted --script "$1" -- mkpart 'boot' 2MB 512MiB
#parted --script "$1" -- mkpart ESP fat32 2MB 512MiB
parted --script "$1" -- mkpart 'boot' fat32 2MB 512MiB set 2 boot on
#parted -s "$1" -- mkpart ESP fat32 1MiB 512MiB
parted -s "$1" -- mkpart primary 512MiB 100%
parted -s "$1" -- print
parted --script "$1" -- mkpart primary 512MiB 100%
parted --script "$1" -- print
}
# In this particular machine we have two NVMe disks
@ -97,26 +103,8 @@ format /dev/sda
format /dev/sdb
# Create partitions (--script to not ask)
#
# We create the 1MB BIOS boot partition at the front.
#
# Note we use "MB" instead of "MiB" because otherwise `--align optimal` has no effect;
# as per documentation https://www.gnu.org/software/parted/manual/html_node/unit.html#unit:
# > Note that as of parted-2.4, when you specify start and/or end values using IEC
# > binary units like "MiB", "GiB", "TiB", etc., parted treats those values as exact
#
# Note: When using `mkpart` on GPT, as per
# https://www.gnu.org/software/parted/manual/html_node/mkpart.html#mkpart
# the first argument to `mkpart` is not a `part-type`, but the GPT partition name:
# ... part-type is one of 'primary', 'extended' or 'logical', and may be specified only with 'msdos' or 'dvh' partition tables.
# A name must be specified for a 'gpt' partition table.
# GPT partition names are limited to 36 UTF-16 chars, see https://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_entries_(LBA_2-33).
#parted --script --align optimal /dev/sda -- mklabel gpt mkpart 'BIOS-boot-partition' 1MB 2MB set 1 bios_grub on mkpart 'data-partition' 2MB '100%'
#parted --script --align optimal /dev/sdb -- mklabel gpt mkpart 'BIOS-boot-partition' 1MB 2MB set 1 bios_grub on mkpart 'data-partition' 2MB '100%'
# Relaod partitions
#partprobe
partprobe
# Wait for all devices to exist
udevadm settle --timeout=5 --exit-if-exists=/dev/sda1
@ -126,31 +114,6 @@ udevadm settle --timeout=5 --exit-if-exists=/dev/sdb1
udevadm settle --timeout=5 --exit-if-exists=/dev/sdb2
udevadm settle --timeout=5 --exit-if-exists=/dev/sdb3
# Wipe any previous RAID signatures
#mdadm --zero-superblock --force /dev/sda2
#mdadm --zero-superblock --force /dev/sdb2
# Create RAIDs
# Note that during creating and boot-time assembly, mdadm cares about the
# host name, and the existence and contents of `mdadm.conf`!
# This also affects the names appearing in /dev/md/ being different
# before and after reboot in general (but we take extra care here
# to pass explicit names, and set HOMEHOST for the rebooting system further
# down, so that the names appear the same).
# Almost all details of this are explained in
# https://bugzilla.redhat.com/show_bug.cgi?id=606481#c14
# and the followup comments by Doug Ledford.
#mdadm --create --run --verbose /dev/md0 --level=1 --raid-devices=2 --homehost=hetzner --name=root0 /dev/sda2 /dev/sdb2
# Assembling the RAID can result in auto-activation of previously-existing LVM
# groups, preventing the RAID block device wiping below with
# `Device or resource busy`. So disable all VGs first.
#vgchange -an
# Wipe filesystem signatures that might be on the RAID from some
# possibly existing older use of the disks (RAID creation does not do that).
# See https://serverfault.com/questions/911370/why-does-mdadm-zero-superblock-preserve-file-system-information
#wipefs -a /dev/md0
# Disable RAID recovery. We don't want this to slow down machine provisioning
# in the rescue mode. It can run in normal operation after reboot.
@ -170,32 +133,31 @@ encrypt /dev/sdb "b"
# /boot partitions
# ----------------
mkfs.fat -F 32 -n boot /dev/sda2
mkfs.fat -F 32 -n boot /dev/sdb2
# PVs
#pvcreate /dev/md0
pvcreate /dev/mapper/a_encrypted
pvcreate /dev/mapper/b_encrypted
# VGs
vgcreate vg /dev/mapper/a_encrypted /dev/mapper/b_encrypted
#vgcreate vg0 /dev/md0
# LVs (--yes to automatically wipe detected file system signatures)
# the root partition should be raid1
#lvcreate --mirrors 1 --type raid1 -L 150G --nosync -n root vg
lvcreate --mirrors 1 --type raid1 -L 150G -n root vg
# Filesystems (-F to not ask on preexisting FS)
mkfs.ext4 -F -L root /dev/mapper/vg-root
#mkfs.ext4 -F -L boot /dev/sda2
mkfs.fat -F 32 -n boot /dev/sda2
#mkfs.vfat -n boot /dev/sda2
#mkfs.ext4 -F -L boot /dev/sdb2
mkfs.fat -F 32 -n boot /dev/sdb2
#mkfs.vfat -n boot /dev/sdb2
# Creating file systems changes their UUIDs.
# Trigger udev so that the entries in /dev/disk/by-uuid get refreshed.
# `nixos-generate-config` depends on those being up-to-date.
@ -206,6 +168,7 @@ udevadm trigger
udevadm settle --timeout=5 --exit-if-exists=/dev/disk/by-label/root
# NixOS pre-installation mounts
# -----------------------------
# Mount target root partition
mount /dev/disk/by-label/root /mnt
@ -215,6 +178,7 @@ mount /dev/sda2 /mnt/boot-1
mount /dev/sdb2 /mnt/boot-2
# Installing nix
# --------------
# Installing nix requires `sudo`; the Hetzner rescue mode doesn't have it.
apt-get install -y sudo
@ -238,6 +202,9 @@ nix-env -iE "_: with import <nixpkgs/nixos> { configuration = {}; }; with config
nixos-generate-config --root /mnt
# Detect
# ------
# Find the name of the network interface that connects us to the Internet.
# Inspired by https://unix.stackexchange.com/questions/14961/how-to-find-out-which-interface-am-i-using-for-connecting-to-the-internet/302613#302613
RESCUE_INTERFACE=$(ip route get 8.8.8.8 | grep -Po '(?<=dev )(\S+)')
@ -274,6 +241,7 @@ cat > /mnt/etc/nixos/configuration.nix <<EOF
{ config, pkgs, modulesPath, lib, ... }:
let
hostName = "hetzner";
# FIXME configure network driver
# in rescue
# apt install -y lshw
# lshw -C network | grep -Poh 'driver=[[:alnum:]]+'
@ -291,34 +259,20 @@ let
gateway = "fe80::1"; # the ipv6 gateway
prefixLength = 64; # shown in the control panel
};
in
{
imports =
[ # Include the results of the hardware scan.
# ./hardware-configuration.nix
# hardware-configuration content
{
imports =
[ (modulesPath + "/installer/scan/not-detected.nix")
./hardware-configuration.nix
];
boot.initrd.availableKernelModules = [ "ahci" "sd_mod" ];
# needed lvm for raid
boot.initrd.kernelModules = [
"dm-snapshot"
"dm_mirror"
"dm_raid"
"dm_region_hash"
];
boot.kernelModules = [ "kvm-intel" ];
boot.extraModulePackages = [ ];
swapDevices = [ ];
powerManagement.cpuFreqGovernor = lib.mkDefault "ondemand";
}
];
# Use GRUB2 as the boot loader.
# We don't use systemd-boot because Hetzner uses BIOS legacy boot.
@ -336,9 +290,9 @@ in
{ path = "/boot-2"; devices = [ "/dev/sdb" ]; }
];
# add later
# fileSystems."/boot-1".options = [ "nofail" ];
# fileSystems."/boot-2".options = [ "nofail" ];
# We want to still be able to boot without one of these
fileSystems."/boot-1".options = [ "nofail" ];
fileSystems."/boot-2".options = [ "nofail" ];
boot.initrd.luks.reusePassphrases = true;
boot.initrd.luks.devices = {
@ -352,14 +306,6 @@ in
};
};
# root
# ----
fileSystems."/" = {
options = [ "noatime" "nodiratime" "discard" ];
device = "/dev/vg/root";
fsType = "ext4";
};
networking.hostName = hostName;
# Network configuration (Hetzner uses static IP assignments, and we don't use DHCP here)
@ -404,7 +350,6 @@ in
/etc/secrets/initrd/ssh_host_rsa_key
/etc/secrets/initrd/ssh_host_ed25519_key
];
};
}