nixos/tests: add a test for os-prober

nixos/tests/os-prober.nix

@@ -0,0 +1,125 @@
+import ./make-test.nix ({pkgs, lib}:
+let
+  # A filesystem image with a (presumably) bootable debian
+  debianImage = pkgs.vmTools.diskImageFuns.debian9i386 {
+    # os-prober cannot detect systems installed on disks without a partition table
+    # so we create the disk ourselves
+    createRootFS = with pkgs; ''
+      ${parted}/bin/parted --script /dev/vda mklabel msdos
+      ${parted}/sbin/parted --script /dev/vda -- mkpart primary ext2 1M -1s
+      mkdir /mnt
+      ${e2fsprogs}/bin/mkfs.ext4 /dev/vda1
+      ${utillinux}/bin/mount -t ext4 /dev/vda1 /mnt
+
+      if test -e /mnt/.debug; then
+        exec ${bash}/bin/sh
+      fi
+      touch /mnt/.debug
+
+      mkdir /mnt/proc /mnt/dev /mnt/sys
+    '';
+    extraPackages = [
+      # /etc/os-release
+      "base-files"
+      # make the disk bootable-looking
+      "grub2" "linux-image-686"
+    ];
+    # install grub
+    postInstall = ''
+      ln -sf /proc/self/mounts > /etc/mtab
+      PATH=/usr/bin:/bin:/usr/sbin:/sbin $chroot /mnt \
+        grub-install /dev/vda --force
+      PATH=/usr/bin:/bin:/usr/sbin:/sbin $chroot /mnt \
+        update-grub
+    '';
+  };
+
+  # options to add the disk to the test vim
+  QEMU_OPTS = "-drive index=2,file=${debianImage}/disk-image.qcow2,read-only,if=virtio";
+
+  # a part of the configuration of the test vm
+  simpleConfig = {
+    boot.loader.grub = {
+      enable = true;
+      useOSProber = true;
+      device = "/dev/vda";
+      # vda is a filesystem without partition table
+      forceInstall = true;
+    };
+    fileSystems."/mnt" = {
+      device = "/dev/vdb1";
+      options = [ "ro" ];
+    };
+    nix.binaryCaches = lib.mkForce [ ];
+    nix.extraOptions =
+      ''
+      hashed-mirrors =
+      connect-timeout = 1
+      '';
+      services.udisks2.enable = lib.mkForce false;
+  };
+  # /etc/nixos/configuration.nix for the vm
+  configFile = pkgs.writeText "configuration.nix"  ''
+    {config, pkgs, ...}: ({
+    imports = 
+          [ ./hardware-configuration.nix
+            <nixpkgs/nixos/modules/testing/test-instrumentation.nix>
+          ];
+    }// (builtins.fromJSON (builtins.readFile ${
+      pkgs.writeText "simpleConfig.json" 
+      (builtins.toJSON simpleConfig)
+    })))
+  '';
+in {
+  name = "os-prober";
+
+  machine = { config, pkgs, ... }: (simpleConfig // {
+    imports = [ ../modules/profiles/installation-device.nix
+                ../modules/profiles/base.nix ];
+      virtualisation.memorySize = 1024;
+      # The test cannot access the network, so any packages
+      # nixos-rebuild needs must be included in the VM.
+      system.extraDependencies = with pkgs;
+        [ sudo
+          libxml2.bin
+          libxslt.bin
+          desktop-file-utils
+          docbook5
+          docbook_xsl_ns
+          unionfs-fuse
+          ntp
+          nixos-artwork.wallpapers.simple-dark-gray-bottom
+          perlPackages.XMLLibXML
+          perlPackages.ListCompare
+          shared-mime-info
+          texinfo
+          xorg.lndir
+          grub2
+
+          # add curl so that rather than seeing the test attempt to download
+          # curl's tarball, we see what it's trying to download
+          curl
+        ];
+  });
+
+  testScript = ''
+    # hack to add the secondary disk
+    $machine->{startCommand} = "QEMU_OPTS=\"\$QEMU_OPTS \"${lib.escapeShellArg QEMU_OPTS} ".$machine->{startCommand};
+
+    $machine->start;
+    $machine->succeed("udevadm settle");
+    $machine->waitForUnit("multi-user.target");
+
+    # check that os-prober works standalone
+    $machine->succeed("${pkgs.os-prober}/bin/os-prober | grep /dev/vdb1");
+
+    # rebuild and test that debian is available in the grub menu
+    $machine->succeed("nixos-generate-config");
+    $machine->copyFileFromHost(
+        "${configFile}",
+        "/etc/nixos/configuration.nix");
+    $machine->succeed("nixos-rebuild boot >&2");
+
+    $machine->succeed("egrep 'menuentry.*debian' /boot/grub/grub.cfg");
+  '';
+})

pkgs/build-support/vm/default.nix

@@ -719,7 +719,7 @@ rec {
     { name, fullName, size ? 4096, urlPrefix
     , packagesList ? "", packagesLists ? [packagesList]
     , packages, extraPackages ? [], postInstall ? ""
-    , extraDebs ? []
+    , extraDebs ? [], createRootFS ? defaultCreateRootFS
     , QEMU_OPTS ? "", memSize ? 512 }:
 
     let
@@ -729,7 +729,7 @@ rec {
       };
     in
       (fillDiskWithDebs {
-        inherit name fullName size postInstall QEMU_OPTS memSize;
+        inherit name fullName size postInstall createRootFS QEMU_OPTS memSize;
         debs = import expr {inherit fetchurl;} ++ extraDebs;
       }) // {inherit expr;};