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|
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.ec2;
in
{
imports = [ ../profiles/headless.nix ./ec2-data.nix ];
options = {
ec2 = {
hvm = mkOption {
default = false;
description = ''
Whether the EC2 instance is a HVM instance.
'';
};
};
};
config = {
system.build.amazonImage =
pkgs.vmTools.runInLinuxVM (
pkgs.runCommand "amazon-image"
{ preVM =
''
mkdir $out
diskImage=$out/nixos.img
${pkgs.vmTools.qemu}/bin/qemu-img create -f raw $diskImage "8G"
mv closure xchg/
'';
buildInputs = [ pkgs.utillinux pkgs.perl ];
exportReferencesGraph =
[ "closure" config.system.build.toplevel ];
}
''
${if cfg.hvm then ''
# Create a single / partition.
${pkgs.parted}/sbin/parted /dev/vda mklabel msdos
${pkgs.parted}/sbin/parted /dev/vda -- mkpart primary ext2 1M -1s
. /sys/class/block/vda1/uevent
mknod /dev/vda1 b $MAJOR $MINOR
# Create an empty filesystem and mount it.
${pkgs.e2fsprogs}/sbin/mkfs.ext4 -L nixos /dev/vda1
${pkgs.e2fsprogs}/sbin/tune2fs -c 0 -i 0 /dev/vda1
mkdir /mnt
mount /dev/vda1 /mnt
'' else ''
# Create an empty filesystem and mount it.
${pkgs.e2fsprogs}/sbin/mkfs.ext4 -L nixos /dev/vda
${pkgs.e2fsprogs}/sbin/tune2fs -c 0 -i 0 /dev/vda
mkdir /mnt
mount /dev/vda /mnt
''}
# The initrd expects these directories to exist.
mkdir /mnt/dev /mnt/proc /mnt/sys
mount -o bind /proc /mnt/proc
mount -o bind /dev /mnt/dev
mount -o bind /sys /mnt/sys
# Copy all paths in the closure to the filesystem.
storePaths=$(perl ${pkgs.pathsFromGraph} /tmp/xchg/closure)
mkdir -p /mnt/nix/store
echo "copying everything (will take a while)..."
cp -prd $storePaths /mnt/nix/store/
# Register the paths in the Nix database.
printRegistration=1 perl ${pkgs.pathsFromGraph} /tmp/xchg/closure | \
chroot /mnt ${config.nix.package}/bin/nix-store --load-db
# Create the system profile to allow nixos-rebuild to work.
chroot /mnt ${config.nix.package}/bin/nix-env \
-p /nix/var/nix/profiles/system --set ${config.system.build.toplevel}
# `nixos-rebuild' requires an /etc/NIXOS.
mkdir -p /mnt/etc
touch /mnt/etc/NIXOS
# `switch-to-configuration' requires a /bin/sh
mkdir -p /mnt/bin
ln -s ${config.system.build.binsh}/bin/sh /mnt/bin/sh
# Install a configuration.nix.
mkdir -p /mnt/etc/nixos
cp ${./amazon-config.nix} /mnt/etc/nixos/configuration.nix
# Generate the GRUB menu.
ln -s vda /dev/xvda
chroot /mnt ${config.system.build.toplevel}/bin/switch-to-configuration boot
umount /mnt/proc /mnt/dev /mnt/sys
umount /mnt
''
);
fileSystems."/".device = "/dev/disk/by-label/nixos";
boot.initrd.kernelModules = [ "xen-blkfront" ];
boot.kernelModules = [ "xen-netfront" ];
# Generate a GRUB menu. Amazon's pv-grub uses this to boot our kernel/initrd.
boot.loader.grub.version = if cfg.hvm then 2 else 1;
boot.loader.grub.device = if cfg.hvm then "/dev/xvda" else "nodev";
boot.loader.grub.timeout = 0;
boot.loader.grub.extraPerEntryConfig = "root (hd0${lib.optionalString cfg.hvm ",0"})";
boot.initrd.postDeviceCommands =
''
# Force udev to exit to prevent random "Device or resource busy
# while trying to open /dev/xvda" errors from fsck.
udevadm control --exit || true
kill -9 -1
'';
# Mount all formatted ephemeral disks and activate all swap devices.
# We cannot do this with the ‘fileSystems’ and ‘swapDevices’ options
# because the set of devices is dependent on the instance type
# (e.g. "m1.large" has one ephemeral filesystem and one swap device,
# while "m1.large" has two ephemeral filesystems and no swap
# devices). Also, put /tmp and /var on /disk0, since it has a lot
# more space than the root device. Similarly, "move" /nix to /disk0
# by layering a unionfs-fuse mount on top of it so we have a lot more space for
# Nix operations.
boot.initrd.postMountCommands =
''
diskNr=0
diskForUnionfs=
for device in /dev/xvd[abcde]*; do
if [ "$device" = /dev/xvda -o "$device" = /dev/xvda1 ]; then continue; fi
fsType=$(blkid -o value -s TYPE "$device" || true)
if [ "$fsType" = swap ]; then
echo "activating swap device $device..."
swapon "$device" || true
elif [ "$fsType" = ext3 ]; then
mp="/disk$diskNr"
diskNr=$((diskNr + 1))
echo "mounting $device on $mp..."
if mountFS "$device" "$mp" "" ext3; then
if [ -z "$diskForUnionfs" ]; then diskForUnionfs="$mp"; fi
fi
else
echo "skipping unknown device type $device"
fi
done
if [ -n "$diskForUnionfs" ]; then
mkdir -m 755 -p $targetRoot/$diskForUnionfs/root
mkdir -m 1777 -p $targetRoot/$diskForUnionfs/root/tmp $targetRoot/tmp
mount --bind $targetRoot/$diskForUnionfs/root/tmp $targetRoot/tmp
if [ ! -e $targetRoot/.ebs ]; then
mkdir -m 755 -p $targetRoot/$diskForUnionfs/root/var $targetRoot/var
mount --bind $targetRoot/$diskForUnionfs/root/var $targetRoot/var
mkdir -p /unionfs-chroot/ro-nix
mount --rbind $targetRoot/nix /unionfs-chroot/ro-nix
mkdir -m 755 -p $targetRoot/$diskForUnionfs/root/nix
mkdir -p /unionfs-chroot/rw-nix
mount --rbind $targetRoot/$diskForUnionfs/root/nix /unionfs-chroot/rw-nix
unionfs -o allow_other,cow,nonempty,chroot=/unionfs-chroot,max_files=32768 /rw-nix=RW:/ro-nix=RO $targetRoot/nix
fi
fi
'';
boot.initrd.extraUtilsCommands =
''
# We need swapon in the initrd.
cp --remove-destination ${pkgs.utillinux}/sbin/swapon $out/bin
'';
# Don't put old configurations in the GRUB menu. The user has no
# way to select them anyway.
boot.loader.grub.configurationLimit = 0;
# Allow root logins only using the SSH key that the user specified
# at instance creation time.
services.openssh.enable = true;
services.openssh.permitRootLogin = "without-password";
# Force getting the hostname from EC2.
networking.hostName = mkDefault "";
# Always include cryptsetup so that Charon can use it.
environment.systemPackages = [ pkgs.cryptsetup ];
boot.initrd.supportedFilesystems = [ "unionfs-fuse" ];
# Prevent logging in as root without a password. This doesn't really matter,
# since the only PAM services that allow logging in with a null
# password are local ones that are inaccessible on EC2 machines.
security.initialRootPassword = mkDefault "!";
};
}
|