Merge pull request #713 from nix-community/interactiveVM

add interactive VMs

README.md

@@ -41,9 +41,8 @@ recursive layouts.
 
 Disko doesn't require installation: it can be run directly from nix-community
 repository. The [Quickstart Guide](./docs/quickstart.md) documents how to run
-Disko in its simplest form when installing NixOS. Alternatively, you can
+Disko in its simplest form when installing NixOS. Alternatively, you can also
-also use the new [disko-install](./docs/disko-install.md) tool, which combines
+use the new [disko-install](./docs/disko-install.md) tool, which combines `disko` and `nixos-install` into one step.
-the `disko` and `nixos-install` into one step.
 
 For information on other use cases, including upgrading from an older version of
 **disko**, using **disko** without NixOS and downloading the module, see the

docs/interactive-vm.md

@@ -0,0 +1,17 @@
+# Running Interactive VMs with disko
+
+disko now exports its own flavor of interactive VMs (similiar to config.system.build.vm).
+Simply import the disko module and build the vm runner with:
+```
+nix build -L '.#nixosConfigurations.mymachine.config.system.build.vmWithDisko'
+```
+
+afterwards you can run the interactive VM with:
+
+```
+result/bin/disko-vm
+```
+
+extraConfig that is set in disko.tests.extraConfig is also applied to the interactive VMs.
+imageSize of the VMs will be determined by the imageSize in the disk type in your disko config.
+memorySize is set by disko.memSize

docs/quickstart.md

@@ -15,7 +15,8 @@ existing partitions. Dual booting with other operating systems is not supported.
 
 ### Step 1: Choose a Disk Configuration
 
-Real-world templates are provided in this [repository](https://github.com/nix-community/disko-templates).
+Real-world templates are provided in this
+[repository](https://github.com/nix-community/disko-templates).
 
 More disk layouts for all filesystems can be also found in the
 [example](https://github.com/nix-community/disko/tree/master/example) directory

lib/default.nix

@@ -16,6 +16,8 @@ let
     # a version of makeDiskImage which runs outside of the store
     makeDiskImagesScript = args: (import ./make-disk-image.nix ({ inherit diskoLib; } // args)).impure;
 
+    makeVMRunner = args: (import ./interactive-vm.nix ({ inherit diskoLib; } // args)).pure;
+
     testLib = import ./tests.nix { inherit lib makeTest eval-config; };
     # like lib.types.oneOf but instead of a list takes an attrset
     # uses the field "type" to find the correct type in the attrset

lib/interactive-vm.nix

@@ -0,0 +1,88 @@
+{ nixosConfig
+, diskoLib
+, pkgs ? nixosConfig.pkgs
+, name ? "${nixosConfig.config.networking.hostName}-disko-images"
+, extraConfig ? { }
+}:
+let
+  lib = pkgs.lib;
+  vm_disko = (diskoLib.testLib.prepareDiskoConfig nixosConfig.config diskoLib.testLib.devices).disko;
+  cfg_ = (lib.evalModules {
+    modules = lib.singleton {
+      # _file = toString input;
+      imports = lib.singleton { disko.devices = vm_disko.devices; };
+      options = {
+        disko.devices = lib.mkOption {
+          type = diskoLib.toplevel;
+        };
+        disko.testMode = lib.mkOption {
+          type = lib.types.bool;
+          default = true;
+        };
+      };
+    };
+  }).config;
+  disks = lib.attrValues cfg_.disko.devices.disk;
+  diskoImages = diskoLib.makeDiskImages {
+    nixosConfig = nixosConfig;
+    copyNixStore = false;
+    extraConfig = {
+      disko.devices = cfg_.disko.devices;
+    };
+    testMode = true;
+  };
+  rootDisk = {
+    name = "root";
+    file = ''"$tmp"/${(builtins.head disks).name}.qcow2'';
+    driveExtraOpts.cache = "writeback";
+    driveExtraOpts.werror = "report";
+    deviceExtraOpts.bootindex = "1";
+    deviceExtraOpts.serial = "root";
+  };
+  otherDisks = map
+    (disk: {
+      name = disk.name;
+      file = ''"$tmp"/${disk.name}.qcow2'';
+      driveExtraOpts.werror = "report";
+    })
+    (builtins.tail disks);
+  vm = (nixosConfig.extendModules {
+    modules = [
+      ({ modulesPath, ... }: {
+        imports = [
+          (modulesPath + "/virtualisation/qemu-vm.nix")
+        ];
+      })
+      {
+        virtualisation.useEFIBoot = nixosConfig.config.disko.tests.efi;
+        virtualisation.memorySize = nixosConfig.config.disko.memSize;
+        virtualisation.useDefaultFilesystems = false;
+        virtualisation.diskImage = null;
+        virtualisation.qemu.drives = [ rootDisk ] ++ otherDisks;
+        boot.zfs.devNodes = "/dev/disk/by-uuid"; # needed because /dev/disk/by-id is empty in qemu-vms
+        boot.zfs.forceImportAll = true;
+      }
+      {
+        # generated from disko config
+        virtualisation.fileSystems = cfg_.disko.devices._config.fileSystems;
+        boot = cfg_.disko.devices._config.boot or { };
+        swapDevices = cfg_.disko.devices._config.swapDevices or [ ];
+      }
+      nixosConfig.config.disko.tests.extraConfig
+    ];
+  }).config.system.build.vm;
+in
+{
+  pure = pkgs.writeDashBin "disko-vm" ''
+    set -efux
+    export tmp=$(mktemp -d)
+    trap 'rm -rf "$tmp"' EXIT
+    ${lib.concatMapStringsSep "\n" (disk: ''
+      ${pkgs.qemu}/bin/qemu-img create -f qcow2 \
+      -b ${diskoImages}/${disk.name}.raw \
+      -F raw "$tmp"/${disk.name}.qcow2
+    '') disks}
+    set +f
+    ${vm}/bin/run-*-vm
+  '';
+}

lib/make-disk-image.nix

@@ -5,6 +5,9 @@
 , name ? "${nixosConfig.config.networking.hostName}-disko-images"
 , extraPostVM ? nixosConfig.config.disko.extraPostVM
 , checked ? false
+, copyNixStore ? true
+, testMode ? false
+, extraConfig ? { }
 }:
 let
   vmTools = pkgs.vmTools.override {
@@ -16,10 +19,14 @@ let
   };
   cleanedConfig = diskoLib.testLib.prepareDiskoConfig nixosConfig.config diskoLib.testLib.devices;
   systemToInstall = nixosConfig.extendModules {
-    modules = [{
+    modules = [
+      extraConfig
+      {
+        disko.testMode = true;
         disko.devices = lib.mkForce cleanedConfig.disko.devices;
         boot.loader.grub.devices = lib.mkForce cleanedConfig.boot.loader.grub.devices;
-    }];
+      }
+    ];
   };
   dependencies = with pkgs; [
     bash
@@ -49,6 +56,7 @@ let
     rootPaths = [ systemToInstall.config.system.build.toplevel ];
   };
   partitioner = ''
+    set -efux
     # running udev, stolen from stage-1.sh
     echo "running udev..."
     ln -sfn /proc/self/fd /dev/fd
@@ -64,10 +72,13 @@ let
     udevadm trigger --action=add
     udevadm settle
 
+    ${lib.optionalString testMode ''
+      export IN_DISKO_TEST=1
+    ''}
     ${systemToInstall.config.system.build.diskoScript}
   '';
 
-  installer = ''
+  installer = lib.optionalString copyNixStore ''
     # populate nix db, so nixos-install doesn't complain
     export NIX_STATE_DIR=${systemToInstall.config.disko.rootMountPoint}/nix/var/nix
     nix-store --load-db < "${closureInfo}/registration"

lib/types/gpt.nix

@@ -45,7 +45,8 @@ in
           };
           priority = lib.mkOption {
             type = lib.types.int;
-            default = if partition.config.size or "" == "100%" then
+            default =
+              if partition.config.size or "" == "100%" then
                 9001
               else if partition.config.type == "EF02" then
               # Boot partition should be created first, because some BIOS implementations require it.

lib/types/luks.nix

@@ -114,19 +114,23 @@ in
       default = ''
         if ! blkid "${config.device}" >/dev/null || ! (blkid "${config.device}" -o export | grep -q '^TYPE='); then
           ${lib.optionalString config.askPassword ''
-            set +x
             askPassword() {
+              if [ -z ''${IN_DISKO_TEST+x} ]; then
+                set +x
                 echo "Enter password for ${config.device}: "
                 IFS= read -r -s password
                 echo "Enter password for ${config.device} again to be safe: "
                 IFS= read -r -s password_check
                 export password
                 [ "$password" = "$password_check" ]
+                set -x
+              else
+                export password=disko
+              fi
             }
             until askPassword; do
               echo "Passwords did not match, please try again."
             done
-            set -x
           ''}
           cryptsetup -q luksFormat ${config.device} ${toString config.extraFormatArgs} ${keyFileArgs}
           ${cryptsetupOpen} --persistent
@@ -147,11 +151,15 @@ in
           dev = ''
             if ! cryptsetup status ${config.name} >/dev/null 2>/dev/null; then
               ${lib.optionalString config.askPassword ''
+                if [ -z ''${IN_DISKO_TEST+x} ]; then
                   set +x
                   echo "Enter password for ${config.device}"
                   IFS= read -r -s password
                   export password
                   set -x
+                else
+                  export password=disko
+                fi
               ''}
               ${cryptsetupOpen}
             fi

lib/types/lvm_vg.nix

@@ -125,7 +125,7 @@ in
     _config = lib.mkOption {
       internal = true;
       readOnly = true;
-      default = [ { boot.initrd.kernelModules = kernelModules; } ] ++
+      default = [{ boot.initrd.kernelModules = kernelModules; }] ++
         map
           (lv: [
             (lib.optional (lv.content != null) lv.content._config)

lib/types/zfs_fs.nix

@@ -59,7 +59,8 @@
         # important to prevent accidental shadowing of mount points
         # since (create order != mount order)
         # -p creates parents automatically
-        default = let
+        default =
+          let
             createOptions = (lib.optionalAttrs (config.mountpoint != null) { mountpoint = config.mountpoint; }) // config.options;
             # All options defined as PROP_ONETIME or PROP_ONETIME_DEFAULT in https://github.com/openzfs/zfs/blob/master/module/zcommon/zfs_prop.c
             onetimeProperties = [
@@ -74,7 +75,8 @@
             ];
             updateOptions = builtins.removeAttrs config.options onetimeProperties;
             mountpoint = config.options.mountpoint or config.mountpoint;
-        in ''
+          in
+          ''
             if ! zfs get type ${config._name} >/dev/null 2>&1; then
               zfs create -up ${config._name} \
                 ${lib.concatStringsSep " " (lib.mapAttrsToList (n: v: "-o ${n}=${v}") (createOptions))}

module.nix

@@ -99,6 +99,15 @@ in
       type = lib.types.bool;
       default = false;
     };
+    testMode = lib.mkOption {
+      internal = true;
+      description = ''
+        this is true if the system is being run in test mode.
+        like a vm test or an interactive vm
+      '';
+      type = lib.types.bool;
+      default = false;
+    };
     tests = {
       efi = lib.mkOption {
         description = ''
@@ -151,6 +160,11 @@ in
         extraSystemConfig = cfg.tests.extraConfig;
         extraTestScript = cfg.tests.extraChecks;
       };
+
+      vmWithDisko = diskoLib.makeVMRunner {
+        inherit pkgs;
+        nixosConfig = args;
+      };
     };