initial try at adding zfs and uefi

2021-03-10 16:01:32 +09:00 · 2021-03-10 16:01:32 +09:00 · 5b7249c6e3
commit 5b7249c6e3
parent 5134fc83e8
1 changed files with 337 additions and 0 deletions
--- a/hosters/hetzner-dedicated/zfs-uefi-nvme-nixos.sh
+++ b/hosters/hetzner-dedicated/zfs-uefi-nvme-nixos.sh
@ -0,0 +1,337 @@
+#!/usr/bin/env bash
+
+# Installs NixOS on a Hetzner server, wiping the server.
+#
+# This is for a specific server configuration; adjust where needed.
+#
+# Prerequisites:
+#   * install a distribution on your server (for example ubuntu)
+#   * boot in rescue mode
+#   * Update the script to put in your SSH pubkey, adjust hostname, NixOS version etc.
+#   * have the following packages installed
+#   * - zfs-initramfs
+#   * - parted
+#   * - sudo
+apt-get install -y sudo parted zfs-initramfs grub-efi-amd64-bin
+#
+# Usage:
+#     ssh root@YOUR_SERVERS_IP bash -s < hetzner-dedicated-wipe-and-install-nixos.sh
+#
+# When the script is done, make sure to boot the server from HD, not rescue mode again.
+
+# Explanations:
+#
+# * Following largely https://nixos.org/nixos/manual/index.html#sec-installing-from-other-distro.
+# * and https://nixos.wiki/wiki/NixOS_on_ZFS
+# * **Important:** First you need to boot in legacy-BIOS mode. Then ask for
+# hetzner support to enable UEFI for you.
+# * 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 SSDs.
+#   We put everything on RAIDZ.
+# * 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.
+
+set -eu
+set -o pipefail
+
+set -x
+
+# Inspect existing disks
+# Should give you something like
+# NAME        MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
+# nvme0n1     259:0    0 476.9G  0 disk
+# ├─nvme0n1p1 259:2    0    32G  0 part
+# │ └─md0       9:0    0    32G  0 raid1 [SWAP]
+# ├─nvme0n1p2 259:3    0   512M  0 part
+# │ └─md1       9:1    0   511M  0 raid1 /boot
+# └─nvme0n1p3 259:4    0 444.4G  0 part
+#   └─md2       9:2    0 444.3G  0 raid1 /
+# nvme1n1     259:1    0 476.9G  0 disk
+# ├─nvme1n1p1 259:5    0    32G  0 part
+# │ └─md0       9:0    0    32G  0 raid1 [SWAP]
+# ├─nvme1n1p2 259:6    0   512M  0 part
+# │ └─md1       9:1    0   511M  0 raid1 /boot
+# └─nvme1n1p3 259:7    0 444.4G  0 part
+#   └─md2       9:2    0 444.3G  0 raid1 /
+lsblk
+
+# check the disks that you have available
+# should give you something like this
+# md-name-rescue:0                             nvme-eui.0025388a01051b58-part1
+# md-name-rescue:1                             nvme-eui.0025388a01051b58-part2
+# md-name-rescue:2                             nvme-eui.0025388a01051b58-part3
+# md-uuid-15391820:32e070f6:ecbfb99e:e983e018  nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00424
+# md-uuid-48379d14:3c44fe11:e6528eec:ad784ade  nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00424-part1
+# md-uuid-f2a894fc:9e90e3af:9af81d28:b120ae1f  nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00424-part2
+# nvme-eui.0025388a01051b55                    nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00424-part3
+# nvme-eui.0025388a01051b55-part1              nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00427
+# nvme-eui.0025388a01051b55-part2              nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00427-part1
+# nvme-eui.0025388a01051b55-part3              nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00427-part2
+# nvme-eui.0025388a01051b58                    nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00427-part3
+#
+# we will use the two disks
+# nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00424
+# nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00427
+ls /dev/disk/by-id
+
+DISK1=/dev/disk/by-id/nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00424
+DISK2=/dev/disk/by-id/nvme-SAMSUNG_MZVLB512HBJQ-00000_S4GENA0NA00427
+MY_HOSTNAME=hetzner-AX41-UEFI-ZFS-NVME
+
+# 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
+umount /mnt
+vgchange -an
+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 $DISK1 mklabel gpt
+parted --script $DISK2 mklabel gpt
+
+# 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 $DISK1 -- mklabel gpt \
+    mkpart 'BIOS-boot-partition' 1MB 2MB set 1 bios_grub on \
+    mkpart "EFI system partition" fat32 2MB 512MB set 2 esp on \
+    mkpart 'data-partition' 512MB '100%'
+
+parted --script --align optimal $DISK2 -- mklabel gpt \
+    mkpart 'BIOS-boot-partition' 1MB 2MB set 1 bios_grub on \
+    mkpart "EFI system partition" fat32 2MB 512MB set 2 esp on \
+    mkpart 'data-partition' 512MB '100%'
+
+# Reload partitions
+partprobe
+
+# Wait for all devices to exist
+udevadm settle --timeout=5 --exit-if-exists=$DISK1-part1
+udevadm settle --timeout=5 --exit-if-exists=$DISK1-part2
+udevadm settle --timeout=5 --exit-if-exists=$DISK1-part3
+udevadm settle --timeout=5 --exit-if-exists=$DISK2-part1
+udevadm settle --timeout=5 --exit-if-exists=$DISK2-part2
+udevadm settle --timeout=5 --exit-if-exists=$DISK2-part3
+
+# Wipe any previous RAID signatures
+mdadm --zero-superblock --force $DISK1
+mdadm --zero-superblock --force $DISK2
+
+# 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.
+# See https://github.com/NixOS/nixpkgs/issues/62444
+udevadm trigger
+
+# taken from https://nixos.wiki/wiki/NixOS_on_ZFS
+zpool create -O mountpoint=none \
+    -O atime=off \
+    -O compression=lz4 \
+    -O xattr=sa \
+    -O acltype=posixacl \
+    -o ashift=12 \
+    rpool mirror $DISK1-part3 $DISK2-part3
+
+# Create the filesystems. This layout is designed so that /home is separate from the root
+# filesystem, as you'll likely want to snapshot it differently for backup purposes. It also
+# makes a "nixos" filesystem underneath the root, to support installing multiple OSes if
+# that's something you choose to do in future.
+zfs create -o mountpoint=legacy rpool/root
+zfs create -o mountpoint=legacy rpool/root/nixos
+zfs create -o mountpoint=legacy rpool/home
+# this creates a special volume for db data see https://wiki.archlinux.org/index.php/ZFS#Databases
+zfs create -o mountpoint=legacy \
+    -o recordsize=8K \
+    -o primarycache=metadata \
+    -o logbias=throughput \
+    rpool/postgres
+
+# NixOS pre-installation mounts
+#
+# Mount the filesystems manually. The nixos installer will detect these mountpoints
+# and save them to /mnt/nixos/hardware-configuration.nix during the install process.
+mount -t zfs rpool/root/nixos /mnt
+mkdir /mnt/home
+mount -t zfs rpool/home /mnt/home
+mkdir /mnt/var/lib/postgres
+mount -t zfs rpool/postgres /mnt/var/lib/postgres
+
+# Create a raid mirror of the first partitions for /boot (GRUB)
+mdadm --create --run --verbose /dev/md127 \
+    --metadata=0.90 \
+    --level=1 \
+    --raid-devices=2 \
+    --homehost=$MY_HOSTNAME \
+    --name=boot_grub \
+    $DISK1-part1 $DISK2-part1
+mkfs.ext4 -m 0 -L boot -j /dev/md127
+mkdir -p /mnt/boot/efi
+mount /dev/md127 /mnt/boot
+
+# Create a raid mirror for the efi boot
+# see https://docs.hetzner.com/robot/dedicated-server/operating-systems/efi-system-partition/
+mdadm --create --run --verbose /dev/md100 \
+    --level 1 \
+    --raid-disks 2 \
+    --metadata 1.0 \
+    --homehost=$MY_HOSTNAME \
+    --name=boot_efi \
+    $DISK1-part2 $DISK2-part2
+mkfs.vfat -F 32 /dev/md100
+mount /dev/md100 /mnt/boot/efi
+PARTITION_UUID=blkid -o value -s UUID /dev/md100
+UUID=$PARTITION_UUID /boot/efi vfat umask=0077 0 1
+grub-install \
+    --target=x86_64-efi \
+    --efi-directory=/boot/efi \
+    --no-floppy \
+    --no-nvram \
+    --removable
+
+# Installing nix
+
+# Allow installing nix as root, see
+#   https://github.com/NixOS/nix/issues/936#issuecomment-475795730
+mkdir -p /etc/nix
+echo "build-users-group =" > /etc/nix/nix.conf
+
+curl -L https://nixos.org/nix/install | sh
+set +u +x # sourcing this may refer to unset variables that we have no control over
+. $HOME/.nix-profile/etc/profile.d/nix.sh
+set -u -x
+
+# Keep in sync with `system.stateVersion` set below!
+nix-channel --add https://nixos.org/channels/nixos-20.09 nixpkgs
+nix-channel --update
+
+# Getting NixOS installation tools
+nix-env -iE "_: with import <nixpkgs/nixos> { configuration = {}; }; with config.system.build; [ nixos-generate-config nixos-install nixos-enter manual.manpages ]"
+
+nixos-generate-config --root /mnt
+
+# Find the name of the network interface that connects us to the Internet.
+# Inspired by https://unix.stackexchange.com/questions/14961/how-to-find-out-which-interface-am-i-using-for-connecting-to-the-internet/302613#302613
+RESCUE_INTERFACE=$(ip route get 8.8.8.8 | grep -Po '(?<=dev )(\S+)')
+
+# Find what its name will be under NixOS, which uses stable interface names.
+# See https://major.io/2015/08/21/understanding-systemds-predictable-network-device-names/#comment-545626
+# NICs for most Hetzner servers are not onboard, which is why we use
+# `ID_NET_NAME_PATH`otherwise it would be `ID_NET_NAME_ONBOARD`.
+INTERFACE_DEVICE_PATH=$(udevadm info -e | grep -Po "(?<=^P: )(.*${RESCUE_INTERFACE})")
+UDEVADM_PROPERTIES_FOR_INTERFACE=$(udevadm info --query=property "--path=$INTERFACE_DEVICE_PATH")
+NIXOS_INTERFACE=$(echo "$UDEVADM_PROPERTIES_FOR_INTERFACE" | grep -o -E 'ID_NET_NAME_PATH=\w+' | cut -d= -f2)
+echo "Determined NIXOS_INTERFACE as '$NIXOS_INTERFACE'"
+
+IP_V4=$(ip route get 8.8.8.8 | grep -Po '(?<=src )(\S+)')
+echo "Determined IP_V4 as $IP_V4"
+
+# Determine Internet IPv6 by checking route, and using ::1
+# (because Hetzner rescue mode uses ::2 by default).
+# The `ip -6 route get` output on Hetzner looks like:
+#   # ip -6 route get 2001:4860:4860:0:0:0:0:8888
+#   2001:4860:4860::8888 via fe80::1 dev eth0 src 2a01:4f8:151:62aa::2 metric 1024  pref medium
+IP_V6="$(ip route get 2001:4860:4860:0:0:0:0:8888 | head -1 | cut -d' ' -f7 | cut -d: -f1-4)::1"
+echo "Determined IP_V6 as $IP_V6"
+
+
+# From https://stackoverflow.com/questions/1204629/how-do-i-get-the-default-gateway-in-linux-given-the-destination/15973156#15973156
+read _ _ DEFAULT_GATEWAY _ < <(ip route list match 0/0); echo "$DEFAULT_GATEWAY"
+echo "Determined DEFAULT_GATEWAY as $DEFAULT_GATEWAY"
+
+
+# Generate `configuration.nix`. Note that we splice in shell variables.
+cat > /mnt/etc/nixos/configuration.nix <<EOF
+{ config, pkgs, ... }:
+
+{
+  imports =
+    [ # Include the results of the hardware scan.
+      ./hardware-configuration.nix
+    ];
+
+  # Use GRUB2 as the boot loader.
+  # We don't use systemd-boot because Hetzner uses BIOS legacy boot.
+  boot.loader.systemd-boot.enable = false;
+  boot.loader.grub = {
+    enable = true;
+    efiSupport = false;
+    devices = [ "$DISK1" "$DISK2" ];
+  };
+
+  networking.hostName = "$MY_HOSTNAME";
+
+  # Network (Hetzner uses static IP assignments, and we don't use DHCP here)
+  networking.useDHCP = false;
+  networking.interfaces."$NIXOS_INTERFACE".ipv4.addresses = [
+    {
+      address = "$IP_V4";
+      prefixLength = 24;
+    }
+  ];
+  networking.interfaces."$NIXOS_INTERFACE".ipv6.addresses = [
+    {
+      address = "$IP_V6";
+      prefixLength = 64;
+    }
+  ];
+  networking.defaultGateway = "$DEFAULT_GATEWAY";
+  networking.defaultGateway6 = { address = "fe80::1"; interface = "$NIXOS_INTERFACE"; };
+  networking.nameservers = [ "8.8.8.8" ];
+
+  # Initial empty root password for easy login:
+  users.users.root.initialHashedPassword = "";
+  services.openssh.permitRootLogin = "prohibit-password";
+
+  users.users.root.openssh.authorizedKeys.keys = [
+    # Replace this by your SSH pubkey!
+    "ssh-rsa "
+  ];
+
+  services.openssh.enable = true;
+
+  # This value determines the NixOS release with which your system is to be
+  # compatible, in order to avoid breaking some software such as database
+  # servers. You should change this only after NixOS release notes say you
+  # should.
+  system.stateVersion = "20.09"; # Did you read the comment?
+
+}
+EOF
+
+# Install NixOS
+PATH="$PATH" NIX_PATH="$NIX_PATH" `which nixos-install` --no-root-passwd --root /mnt --max-jobs 40
+
+# umount /mnt
+
+# reboot