nixpkgs/nixos/modules/virtualisation/amazon-image.nix
Rob Vermaas 3da94435c0 Add option ec2.hvm, to set some boot configuration specific for EC2 HVM instances.
(cherry picked from commit 35c76d917307b7ac405486855cfe63021810dba5)

Conflicts:
	nixos/modules/virtualisation/amazon-image.nix
2014-05-21 16:37:53 +02:00

184 lines
6.6 KiB
Nix
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

{ 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 "4G"
mv closure xchg/
'';
buildInputs = [ pkgs.utillinux pkgs.perl ];
exportReferencesGraph =
[ "closure" config.system.build.toplevel ];
}
''
# Create an empty filesystem and mount it.
${pkgs.e2fsprogs}/sbin/mkfs.ext4 -L nixos /dev/vda
${pkgs.e2fsprogs}/sbin/tune2fs -c 0 -i 0 /dev/vda
mkdir /mnt
mount /dev/vda /mnt
# The initrd expects these directories to exist.
mkdir /mnt/dev /mnt/proc /mnt/sys
mount -o bind /proc /mnt/proc
# Copy all paths in the closure to the filesystem.
storePaths=$(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.
chroot /mnt ${config.system.build.toplevel}/bin/switch-to-configuration boot
umount /mnt/proc
umount /mnt
''
);
fileSystems."/".device = "/dev/disk/by-label/nixos";
boot.initrd.kernelModules = [ "xen-blkfront" ];
boot.kernelModules = [ "xen-netfront" ];
# Generate a GRUB menu. Amazon's pv-grub uses this to boot our kernel/initrd.
boot.loader.grub.version = 1;
boot.loader.grub.device = if cfg.hvm then "/dev/xvda" else "nodev";
boot.loader.grub.timeout = 0;
boot.loader.grub.extraPerEntryConfig = "root (hd0${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 ${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 "!";
};
}