{ config, pkgs, ... }: with pkgs.lib; { system.build.amazonImage = pkgs.vmTools.runInLinuxVM ( pkgs.runCommand "amazon-image" { preVM = '' mkdir $out diskImage=$out/nixos.img ${pkgs.vmTools.kvm}/bin/qemu-img create -f raw $diskImage "4G" ''; buildInputs = [ pkgs.utillinux pkgs.perl ]; exportReferencesGraph = [ "closure" config.system.build.toplevel ]; } '' # Create an empty filesystem and mount it. ${pkgs.e2fsprogs}/sbin/mkfs.ext3 -L nixos /dev/vda ${pkgs.e2fsprogs}/sbin/tune2fs -c 0 -i 0 /dev/vda mkdir /mnt mount /dev/vda /mnt # The initrd expects these directories to exist. mkdir /mnt/dev /mnt/proc /mnt/sys # Copy all paths in the closure to the filesystem. storePaths=$(perl ${pkgs.pathsFromGraph} $ORIG_TMPDIR/closure) mkdir -p /mnt/nix/store cp -prvd $storePaths /mnt/nix/store/ # Register the paths in the Nix database. printRegistration=1 perl ${pkgs.pathsFromGraph} $ORIG_TMPDIR/closure | \ chroot /mnt ${config.environment.nix}/bin/nix-store --load-db # Create the system profile to allow nixos-rebuild to work. chroot /mnt ${config.environment.nix}/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 # 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 '' ); fileSystems = [ { mountPoint = "/"; device = "/dev/disk/by-label/nixos"; } { mountPoint = "/ephemeral0"; device = "/dev/xvdc"; neededForBoot = true; } ]; swapDevices = [ { device = "/dev/xvdb"; } ]; boot.initrd.kernelModules = [ "xen-blkfront" "aufs" ]; boot.kernelModules = [ "xen-netfront" ]; boot.extraModulePackages = [ config.boot.kernelPackages.aufs2 ]; # Generate a GRUB menu. Amazon's pv-grub uses this to boot our kernel/initrd. boot.loader.grub.device = "nodev"; boot.loader.grub.timeout = 0; boot.loader.grub.extraPerEntryConfig = "root (hd0)"; # Put /tmp and /var on /ephemeral0, which has a lot more space. # Unfortunately we can't do this with the `fileSystems' option # because it has no support for creating the source of a bind # mount. Also, "move" /nix to /ephemeral0 by layering an AUFS # on top of it so we have a lot more space for Nix operations. boot.initrd.postMountCommands = '' mkdir -m 1777 -p $targetRoot/ephemeral0/tmp mkdir -m 1777 -p $targetRoot/tmp mount --bind $targetRoot/ephemeral0/tmp $targetRoot/tmp mkdir -m 755 -p $targetRoot/ephemeral0/var mkdir -m 755 -p $targetRoot/var mount --bind $targetRoot/ephemeral0/var $targetRoot/var mkdir -m 755 -p $targetRoot/ephemeral0/nix mount -t aufs -o dirs=$targetRoot/ephemeral0/nix=rw:$targetRoot/nix=rr none $targetRoot/nix ''; # There are no virtual consoles. services.mingetty.ttys = [ ]; # 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"; # Obtain the SSH key and host name at startup time. jobs.fetchEC2Data = { name = "fetch-ec2-data"; startOn = "ip-up"; task = true; script = '' echo "obtaining SSH key..." mkdir -p /root/.ssh ${pkgs.curl}/bin/curl --retry 3 --retry-delay 0 --fail \ -o /root/key.pub \ http://169.254.169.254/1.0/meta-data/public-keys/0/openssh-key if [ $? -eq 0 -a -e /root/key.pub ]; then 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 rm -f /root/key.pub fi # Print the host public key on the console so that the user # can obtain it securely by parsing the output of # ec2-get-console-output. echo "-----BEGIN SSH HOST KEY FINGERPRINTS-----" > /dev/console ${pkgs.openssh}/bin/ssh-keygen -l -f /etc/ssh/ssh_host_dsa_key.pub > /dev/console echo "-----END SSH HOST KEY FINGERPRINTS-----" > /dev/console echo "setting host name..." ${pkgs.nettools}/bin/hostname $(${pkgs.curl}/bin/curl http://169.254.169.254/1.0/meta-data/hostname) ''; }; }