Commit 246d09fe authored by Linus Heckemann's avatar Linus Heckemann
Browse files

qemu-vm: use nixos module patterns for filesystems

parent bf41254a

nixos/modules/virtualisation/qemu-vm.nix

+22 −27
Original line number Diff line number Diff line
@@ -1006,14 +1006,15 @@ in 
      }) cfg.emptyDiskImages)

    ];



    fileSystems = mkVMOverride cfg.fileSystems;



    # Mount the host filesystem via 9P, and bind-mount the Nix store

    # of the host into our own filesystem.  We use mkVMOverride to

    # allow this module to be applied to "normal" NixOS system

    # configuration, where the regular value for the `fileSystems'

    # attribute should be disregarded for the purpose of building a VM

    # test image (since those filesystems don't exist in the VM).

    fileSystems =

    let

    virtualisation.fileSystems = let

      mkSharedDir = tag: share:

        {

          name =
@@ -1027,48 +1028,42 @@ in 
            [ "trans=virtio" "version=9p2000.L"  "msize=${toString cfg.msize}" ]

            ++ lib.optional (tag == "nix-store") "cache=loose";

        };

    in

      mkVMOverride (cfg.fileSystems //

      optionalAttrs cfg.useDefaultFilesystems {

        "/".device = cfg.bootDevice;

        "/".fsType = "ext4";

        "/".autoFormat = true;

      } //

      optionalAttrs (cfg.diskImage == null) {

        "/".device = "tmpfs";

        "/".fsType = "tmpfs";

      } //

      optionalAttrs config.boot.tmpOnTmpfs {

        "/tmp" = {

    in lib.mkMerge [

      (lib.mapAttrs' mkSharedDir cfg.sharedDirectories)

      {

        "/" = lib.mkIf cfg.useDefaultFilesystems (if cfg.diskImage == null then {

          device = "tmpfs";

          fsType = "tmpfs";

        } else {

          device = cfg.bootDevice;

          fsType = "ext4";

          autoFormat = true;

        });

        "/tmp" = lib.mkIf config.boot.tmpOnTmpfs {

          device = "tmpfs";

          fsType = "tmpfs";

          neededForBoot = true;

          # Sync with systemd's tmp.mount;

          options = [ "mode=1777" "strictatime" "nosuid" "nodev" "size=${toString config.boot.tmpOnTmpfsSize}" ];

        };

      } //

      optionalAttrs cfg.useNixStoreImage {

        "/nix/${if cfg.writableStore then ".ro-store" else "store"}" = {

        "/nix/${if cfg.writableStore then ".ro-store" else "store"}" = lib.mkIf cfg.useNixStoreImage {

          device = "${lookupDriveDeviceName "nix-store" cfg.qemu.drives}";

          neededForBoot = true;

          options = [ "ro" ];

        };

      } //

      optionalAttrs (cfg.writableStore && cfg.writableStoreUseTmpfs) {

        "/nix/.rw-store" = {

        "/nix/.rw-store" = lib.mkIf (cfg.writableStore && cfg.writableStoreUseTmpfs) {

          fsType = "tmpfs";

          options = [ "mode=0755" ];

          neededForBoot = true;

        };

      } //

      optionalAttrs cfg.useBootLoader {

        # see note [Disk layout with `useBootLoader`]

        "/boot" = {

        "/boot" = lib.mkIf cfg.useBootLoader {

          device = "${lookupDriveDeviceName "boot" cfg.qemu.drives}2"; # 2 for e.g. `vdb2`, as created in `bootDisk`

          fsType = "vfat";

          noCheck = true; # fsck fails on a r/o filesystem

        };

      } // lib.mapAttrs' mkSharedDir cfg.sharedDirectories);

      }

    ];



    boot.initrd.systemd = lib.mkIf (config.boot.initrd.systemd.enable && cfg.writableStore) {

      mounts = [{