nixpkgs/nixos/modules/virtualisation/google-compute-image.nix
William A. Kennington III aa5d6922c5 Revert "Set boot.loader.grub.configurationLimit to 1 for gce/azure/amazon images. Setting to 0 results in empty grub config."
The issue was that grub was not building the default entry which would
leave systems unbootable. This can now be safely reverted as the default
entry is being built once again.

This reverts commit fd1fb0403c.
2015-05-29 13:26:51 -07:00

262 lines
9.3 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
diskSize = "100G";
in
{
imports = [ ../profiles/headless.nix ../profiles/qemu-guest.nix ];
# https://cloud.google.com/compute/docs/tutorials/building-images
networking.firewall.enable = mkDefault false;
system.build.googleComputeImage =
pkgs.vmTools.runInLinuxVM (
pkgs.runCommand "google-compute-image"
{ preVM =
''
mkdir $out
diskImage=$out/$diskImageBase
truncate $diskImage --size ${diskSize}
mv closure xchg/
'';
postVM =
''
PATH=$PATH:${pkgs.gnutar}/bin:${pkgs.gzip}/bin
pushd $out
mv $diskImageBase disk.raw
tar -Szcf $diskImageBase.tar.gz disk.raw
rm $out/disk.raw
popd
'';
diskImageBase = "nixos-${config.system.nixosVersion}-${pkgs.stdenv.system}.raw";
buildInputs = [ pkgs.utillinux pkgs.perl ];
exportReferencesGraph =
[ "closure" config.system.build.toplevel ];
}
''
# Create partition table
${pkgs.parted}/sbin/parted /dev/vda mklabel msdos
${pkgs.parted}/sbin/parted /dev/vda mkpart primary ext4 1 ${diskSize}
${pkgs.parted}/sbin/parted /dev/vda print
. /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
${pkgs.e2fsprogs}/sbin/tune2fs -c 0 -i 0 /dev/vda1
mkdir /mnt
mount /dev/vda1 /mnt
# The initrd expects these directories to exist.
mkdir /mnt/dev /mnt/proc /mnt/sys
mount --bind /proc /mnt/proc
mount --bind /dev /mnt/dev
mount --bind /sys /mnt/sys
# Copy all paths in the closure to the filesystem.
storePaths=$(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 --option build-users-group ""
# 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} \
--option build-users-group ""
# `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 /mnt/boot/grub
cp ${./google-compute-config.nix} /mnt/etc/nixos/configuration.nix
# Generate the GRUB menu.
ln -s vda /dev/sda
chroot /mnt ${config.system.build.toplevel}/bin/switch-to-configuration boot
umount /mnt/proc /mnt/dev /mnt/sys
umount /mnt
''
);
fileSystems."/".label = "nixos";
boot.kernelParams = [ "console=ttyS0" "panic=1" "boot.panic_on_fail" ];
boot.initrd.kernelModules = [ "virtio_scsi" ];
boot.kernelModules = [ "virtio_pci" "virtio_net" ];
# Generate a GRUB menu. Amazon's pv-grub uses this to boot our kernel/initrd.
boot.loader.grub.device = "/dev/sda";
boot.loader.grub.timeout = 0;
# Don't put old configurations in the GRUB menu. The user has no
# way to select them anyway.
boot.loader.grub.configurationLimit = 0;
# Allow root logins only using the SSH key that the user specified
# at instance creation time.
services.openssh.enable = true;
services.openssh.permitRootLogin = "without-password";
services.openssh.passwordAuthentication = mkDefault false;
# Force getting the hostname from Google Compute.
networking.hostName = mkDefault "";
# Always include cryptsetup so that NixOps can use it.
environment.systemPackages = [ pkgs.cryptsetup ];
# Configure default metadata hostnames
networking.extraHosts = ''
169.254.169.254 metadata.google.internal metadata
'';
services.ntp.servers = [ "metadata.google.internal" ];
networking.usePredictableInterfaceNames = false;
systemd.services.fetch-ssh-keys =
{ description = "Fetch host keys and authorized_keys for root user";
wantedBy = [ "sshd.service" ];
before = [ "sshd.service" ];
after = [ "network-online.target" "ip-up.target" ];
wants = [ "network-online.target" "ip-up.target" ];
script = let wget = "${pkgs.wget}/bin/wget --retry-connrefused -t 15 --waitretry=10 --header='Metadata-Flavor: Google'"; in
''
# When dealing with cryptographic keys, we want to keep things private.
umask 077
# Don't download the SSH key if it has already been downloaded
if ! [ -e /root/.ssh/authorized_keys ]; then
echo "obtaining SSH key..."
mkdir -m 0700 -p /root/.ssh
${wget} -O /root/authorized-keys-metadata http://metadata.google.internal/0.1/meta-data/authorized-keys
if [ $? -eq 0 -a -e /root/authorized-keys-metadata ]; then
cat /root/authorized-keys-metadata | cut -d: -f2- > /root/key.pub
if ! grep -q -f /root/key.pub /root/.ssh/authorized_keys; then
cat /root/key.pub >> /root/.ssh/authorized_keys
echo "new key added to authorized_keys"
fi
chmod 600 /root/.ssh/authorized_keys
fi
rm -f /root/key.pub /root/authorized-keys-metadata
fi
countKeys=0
${flip concatMapStrings config.services.openssh.hostKeys (k :
let kName = baseNameOf k.path; in ''
echo "trying to obtain SSH private host key ${kName}"
${wget} -O /root/${kName} http://metadata.google.internal/0.1/meta-data/attributes/${kName} && :
if [ $? -eq 0 -a -e /root/${kName} ]; then
countKeys=$((countKeys+1))
mv -f /root/${kName} ${k.path}
echo "downloaded ${k.path}"
chmod 600 ${k.path}
${config.programs.ssh.package}/bin/ssh-keygen -y -f ${k.path} > ${k.path}.pub
chmod 644 ${k.path}.pub
fi
rm -f /root/${kName}
''
)}
if [[ $countKeys -le 0 ]]; then
echo "failed to obtain any SSH private host keys."
false
fi
'';
serviceConfig.Type = "oneshot";
serviceConfig.RemainAfterExit = true;
serviceConfig.StandardError = "journal+console";
serviceConfig.StandardOutput = "journal+console";
};
# Setings taken from https://cloud.google.com/compute/docs/tutorials/building-images#providedkernel
boot.kernel.sysctl = {
# enables syn flood protection
"net.ipv4.tcp_syncookies" = mkDefault "1";
# ignores source-routed packets
"net.ipv4.conf.all.accept_source_route" = mkDefault "0";
# ignores source-routed packets
"net.ipv4.conf.default.accept_source_route" = mkDefault "0";
# ignores ICMP redirects
"net.ipv4.conf.all.accept_redirects" = mkDefault "0";
# ignores ICMP redirects
"net.ipv4.conf.default.accept_redirects" = mkDefault "0";
# ignores ICMP redirects from non-GW hosts
"net.ipv4.conf.all.secure_redirects" = mkDefault "1";
# ignores ICMP redirects from non-GW hosts
"net.ipv4.conf.default.secure_redirects" = mkDefault "1";
# don't allow traffic between networks or act as a router
"net.ipv4.ip_forward" = mkDefault "0";
# don't allow traffic between networks or act as a router
"net.ipv4.conf.all.send_redirects" = mkDefault "0";
# don't allow traffic between networks or act as a router
"net.ipv4.conf.default.send_redirects" = mkDefault "0";
# reverse path filtering - IP spoofing protection
"net.ipv4.conf.all.rp_filter" = mkDefault "1";
# reverse path filtering - IP spoofing protection
"net.ipv4.conf.default.rp_filter" = mkDefault "1";
# ignores ICMP broadcasts to avoid participating in Smurf attacks
"net.ipv4.icmp_echo_ignore_broadcasts" = mkDefault "1";
# ignores bad ICMP errors
"net.ipv4.icmp_ignore_bogus_error_responses" = mkDefault "1";
# logs spoofed, source-routed, and redirect packets
"net.ipv4.conf.all.log_martians" = mkDefault "1";
# log spoofed, source-routed, and redirect packets
"net.ipv4.conf.default.log_martians" = mkDefault "1";
# implements RFC 1337 fix
"net.ipv4.tcp_rfc1337" = mkDefault "1";
# randomizes addresses of mmap base, heap, stack and VDSO page
"kernel.randomize_va_space" = mkDefault "2";
# provides protection from ToCToU races
"fs.protected_hardlinks" = mkDefault "1";
# provides protection from ToCToU races
"fs.protected_symlinks" = mkDefault "1";
# makes locating kernel addresses more difficult
"kernel.kptr_restrict" = mkDefault "1";
# set ptrace protections
"kernel.yama.ptrace_scope" = mkDefault "1";
# set perf only available to root
"kernel.perf_event_paranoid" = mkDefault "2";
};
}