about summary refs log tree commit diff
path: root/nixos/modules/virtualisation/google-compute-image.nix
blob: d55b742024367eb82ca3797e3c46a9cf57b756b2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
{ config, lib, pkgs, ... }:

with lib;
let
  diskSize = "100G";
in
{
  imports = [ ../profiles/headless.nix ../profiles/qemu-guest.nix ];

  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

          # 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 /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" ];

  # 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";

  # 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
  '';

  systemd.services.fetch-root-authorized-keys =
    { description = "Fetch authorized_keys for root user";

      wantedBy = [ "multi-user.target" ];
      before = [ "sshd.service" ];
      after = [ "network.target" ];

      path  = [ pkgs.curl ];
      script =
        ''
          # Don't download the SSH key if it has already been downloaded
          if ! [ -e /root/.ssh/authorized_keys ]; then
                echo "obtaining SSH key..."
                mkdir -p /root/.ssh
                curl -o /root/authorized-keys-metadata http://metadata/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
                    rm -f /root/key.pub /root/authorized-keys-metadata
                fi
          fi
        '';
      serviceConfig.Type = "oneshot";
      serviceConfig.RemainAfterExit = true;
     };


}