libvirt: Allow control over boot image configuration

nix/libvirtd-image.nix

@@ -1,91 +1,214 @@
-{ system ? builtins.currentSystem, size ? "10" }:
 let
- pkgs = import <nixpkgs> {};
- config = (import <nixpkgs/nixos/lib/eval-config.nix> {
- inherit system;
- modules = [ {
- fileSystems."/".device = "/dev/disk/by-label/nixos";
-
- boot.loader.grub.version = 2;
- boot.loader.grub.device = "/dev/sda";
- boot.loader.timeout = 0;
-
- services.openssh.enable = true;
- services.openssh.startWhenNeeded = false;
- services.openssh.extraConfig = "UseDNS no";
- } ];
- }).config;
-
-in pkgs.vmTools.runInLinuxVM (
- pkgs.runCommand "libvirtd-image"
- { memSize = 768;
- preVM =
+ makeconfig = { system, config }:
+ (import <nixpkgs/nixos/lib/eval-config.nix> {
+ inherit system;
+ modules = [ config ];
+ }).config;
+
+in rec {
+ base_image_config = {
+ fileSystems."/".device = "/dev/disk/by-label/nixos";
+
+ boot.loader.grub.version = 2;
+ boot.loader.grub.device = "/dev/sda";
+ boot.loader.timeout = 0;
+ };
+
+
+ create_nixos_image = {
+ system ? builtins.currentSystem,
+ pkgs ? import <nixpkgs> {},
+ size ? "10",
+ config ? base_image_config
+ }:
+ let
+ cfg = makeconfig { inherit system config; };
+
+ in pkgs.vmTools.runInLinuxVM (
+ # TODO: Use <nixpkgs/nixos/lib/make-disk-image.nix> when
+ # https://github.com/NixOS/nixpkgs/issues/20471 is fixed
+ pkgs.runCommand "libvirtd-image"
+ { memSize = 768;
+ preVM =
+ ''
+ mkdir $out
+ diskImage=$out/image
+ ${pkgs.vmTools.qemu}/bin/qemu-img create -f qcow2 $diskImage "${size}G"
+ mv closure xchg/
+ '';
+ postVM =
+ ''
+ mv $diskImage $out/disk.qcow2
+ '';
+ buildInputs = [ pkgs.utillinux pkgs.perl ];
+ exportReferencesGraph =
+ [ "closure" cfg.system.build.toplevel ];
+ }
+ ''
+ # 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
+ ${pkgs.e2fsprogs}/sbin/tune2fs -c 0 -i 0 /dev/vda1
+ mkdir /mnt
+ mount /dev/vda1 /mnt
+
+ # The initrd expects these directories to exist.
+ mkdir /mnt/dev /mnt/proc /mnt/sys
+ mount --bind /proc /mnt/proc
+ mount --bind /dev /mnt/dev
+ mount --bind /sys /mnt/sys
+
+ # Copy all paths in the closure to the filesystem.
+ storePaths=$(perl ${pkgs.pathsFromGraph} /tmp/xchg/closure)
+
+ echo "filling Nix store..."
+ mkdir -p /mnt/nix/store
+ set -f
+ cp -prd $storePaths /mnt/nix/store/
+
+ mkdir -p /mnt/etc/nix
+ echo 'build-users-group = ' > /mnt/etc/nix/nix.conf
+
+ # Register the paths in the Nix database.
+ printRegistration=1 perl ${pkgs.pathsFromGraph} /tmp/xchg/closure | \
+ chroot /mnt ${cfg.nix.package.out}/bin/nix-store --load-db
+
+ # Create the system profile to allow nixos-rebuild to work.
+ chroot /mnt ${cfg.nix.package.out}/bin/nix-env \
+ -p /nix/var/nix/profiles/system --set ${cfg.system.build.toplevel}
+
+ # `nixos-rebuild' requires an /etc/NIXOS.
+ mkdir -p /mnt/etc/nixos
+ touch /mnt/etc/NIXOS
+
+ # `switch-to-configuration' requires a /bin/sh
+ mkdir -p /mnt/bin
+ ln -s ${cfg.system.build.binsh}/bin/sh /mnt/bin/sh
+
+ # Generate the GRUB menu.
+ ln -s vda /dev/sda
+ chroot /mnt ${cfg.system.build.toplevel}/bin/switch-to-configuration boot
+
+ umount /mnt/proc /mnt/dev /mnt/sys
+ umount /mnt
+ ''
+ );
+
+
+ edit_image = {
+ pkgs ? import <nixpkgs> {},
+ base_image,
+ cmd
+ }:
+ pkgs.vmTools.runInLinuxVM (
+ pkgs.runCommand "libvirtd-edit-image"
+ { memSize = 768;
+ preVM =
+ ''
+ mkdir $out
+ diskImage=$out/image
+ ${pkgs.vmTools.qemu}/bin/qemu-img create -f qcow2 -b ${base_image}/disk.qcow2 $diskImage
+ '';
+ buildInputs = [ pkgs.utillinux ];
+ postVM =
+ ''
+ mv $diskImage $out/disk.qcow2
+ '';
+ }
  ''
- mkdir $out
- diskImage=$out/image
- ${pkgs.vmTools.qemu}/bin/qemu-img create -f qcow2 $diskImage "${size}G"
- mv closure xchg/
- '';
- postVM =
+ . /sys/class/block/vda1/uevent
+ mknod /dev/vda1 b $MAJOR $MINOR
+ mkdir /mnt
+ mount /dev/vda1 /mnt
+
+ ${cmd}
+
+ umount /mnt
  ''
- mv $diskImage $out/disk.qcow2
- '';
- buildInputs = [ pkgs.utillinux pkgs.perl ];
- exportReferencesGraph =
- [ "closure" config.system.build.toplevel ];
- }
- ''
- # 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
- ${pkgs.e2fsprogs}/sbin/tune2fs -c 0 -i 0 /dev/vda1
- mkdir /mnt
- mount /dev/vda1 /mnt
-
- # The initrd expects these directories to exist.
- mkdir /mnt/dev /mnt/proc /mnt/sys
- mount --bind /proc /mnt/proc
- mount --bind /dev /mnt/dev
- mount --bind /sys /mnt/sys
-
- # Copy all paths in the closure to the filesystem.
- storePaths=$(perl ${pkgs.pathsFromGraph} /tmp/xchg/closure)
-
- echo "filling Nix store..."
- mkdir -p /mnt/nix/store
- set -f
- cp -prd $storePaths /mnt/nix/store/
-
- mkdir -p /mnt/etc/nix
- echo 'build-users-group = ' > /mnt/etc/nix/nix.conf
-
- # Register the paths in the Nix database.
- printRegistration=1 perl ${pkgs.pathsFromGraph} /tmp/xchg/closure | \
- chroot /mnt ${config.nix.package.out}/bin/nix-store --load-db
-
- # Create the system profile to allow nixos-rebuild to work.
- chroot /mnt ${config.nix.package.out}/bin/nix-env \
- -p /nix/var/nix/profiles/system --set ${config.system.build.toplevel}
-
- # `nixos-rebuild' requires an /etc/NIXOS.
- mkdir -p /mnt/etc/nixos
- 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
-
- # 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
- ''
-)
+ );
+
+
+ deploy_in_nixos_image = {
+ system ? builtins.currentSystem,
+ pkgs ? import <nixpkgs> {},
+ base_image,
+ config
+ }:
+ let
+ cfg = makeconfig { inherit system config; };
+
+ in pkgs.vmTools.runInLinuxVM (
+ pkgs.runCommand "libvirtd-deploy-in-nixos-image"
+ { memSize = 768;
+ preVM =
+ ''
+ mkdir $out
+ diskImage=$out/image
+ ${pkgs.vmTools.qemu}/bin/qemu-img create -f qcow2 -b ${base_image}/disk.qcow2 $diskImage
+ mv closure xchg/
+ '';
+ postVM =
+ ''
+ mv $diskImage $out/disk.qcow2
+ '';
+ buildInputs = [ pkgs.utillinux pkgs.perl ];
+ exportReferencesGraph =
+ [ "closure" cfg.system.build.toplevel ];
+ }
+ ''
+ . /sys/class/block/vda1/uevent
+ mknod /dev/vda1 b $MAJOR $MINOR
+ mkdir /mnt
+ mount /dev/vda1 /mnt
+
+ # The initrd expects these directories to exist.
+ mount --bind /proc /mnt/proc
+ mount --bind /dev /mnt/dev
+ mount --bind /sys /mnt/sys
+
+ # Avoid "groups does not exist" warnings
+ mkdir -p /etc/nix
+ echo 'build-users-group = ' > /etc/nix/nix.conf
+ mkdir -p /mnt/etc/nix
+ echo 'build-users-group = ' > /mnt/etc/nix/nix.conf
+
+ sourceStore='${pkgs.nix}/bin/nix-store'
+ targetStore='chroot /mnt ${cfg.nix.package.out}/bin/nix-store'
 
+ echo "filling Nix store..."
+ set -f
+
+ # Copy missing paths in the closure to the target nix store.
+ storePaths=$(perl ${pkgs.pathsFromGraph} /tmp/xchg/closure)
+ missing=$(NIX_DB_DIR=/mnt/nix/var/nix/db $sourceStore --check-validity --print-invalid $storePaths)
+ for path in $missing; do
+ ${pkgs.rsync}/bin/rsync -a $path /mnt/nix/store/
+ done
+
+ # Register the paths in the Nix database.
+ $targetStore --register-validity < /tmp/xchg/closure
+
+ # TODO: Replace with the following
+ # when https://github.com/NixOS/nix/issues/1134 is fixed
+ #printRegistration=1 perl ${pkgs.pathsFromGraph} /tmp/xchg/closure | $sourceStore --load-db
+ #$sourceStore --export $missing | $targetStore --import
+
+
+ # Create the system profile to allow nixos-rebuild to work.
+ chroot /mnt ${cfg.nix.package.out}/bin/nix-env \
+ -p /nix/var/nix/profiles/system --set ${cfg.system.build.toplevel}
+
+ # Generate the GRUB menu.
+ ln -s vda /dev/sda
+ chroot /mnt ${cfg.system.build.toplevel}/bin/switch-to-configuration boot
+
+ umount /mnt/proc /mnt/dev /mnt/sys
+ umount /mnt
+ ''
+ );
+}