pkgs.vmTools.fillDiskWithRPMs

The following is the current implementation of this function.

fillDiskWithRPMs =
    {
      size ? 4096,
      rpms,
      name,
      fullName,
      preInstall ? "",
      postInstall ? "",
      runScripts ? true,
      createRootFS ? defaultCreateRootFS,
      QEMU_OPTS ? "",
      memSize ? 512,
      unifiedSystemDir ? false,
    }:

    runInLinuxVM (
      stdenv.mkDerivation {
        inherit
          name
          preInstall
          postInstall
          rpms
          QEMU_OPTS
          memSize
          ;
        preVM = createEmptyImage { inherit size fullName; };

        buildCommand = ''
          ${createRootFS}

          chroot=$(type -tP chroot)

          # Make the Nix store available in /mnt, because that's where the RPMs live.
          mkdir -p /mnt${storeDir}
          ${util-linux}/bin/mount -o bind ${storeDir} /mnt${storeDir}
          # Some programs may require devices in /dev to be available (e.g. /dev/random)
          ${util-linux}/bin/mount -o bind /dev /mnt/dev

          # Newer distributions like Fedora 18 require /lib etc. to be
          # symlinked to /usr.
          ${lib.optionalString unifiedSystemDir ''
            mkdir -p /mnt/usr/bin /mnt/usr/sbin /mnt/usr/lib /mnt/usr/lib64
            ln -s /usr/bin /mnt/bin
            ln -s /usr/sbin /mnt/sbin
            ln -s /usr/lib /mnt/lib
            ln -s /usr/lib64 /mnt/lib64
            ${util-linux}/bin/mount -t proc none /mnt/proc
          ''}

          echo "unpacking RPMs..."
          set +o pipefail
          for i in $rpms; do
              echo "$i..."
              ${rpm}/bin/rpm2cpio "$i" | chroot /mnt ${cpio}/bin/cpio -i --make-directories --unconditional
          done

          eval "$preInstall"

          echo "initialising RPM DB..."
          PATH=/usr/bin:/bin:/usr/sbin:/sbin $chroot /mnt \
            ldconfig -v || true
          PATH=/usr/bin:/bin:/usr/sbin:/sbin $chroot /mnt \
            rpm --initdb

          ${util-linux}/bin/mount -o bind /tmp /mnt/tmp

          echo "installing RPMs..."
          PATH=/usr/bin:/bin:/usr/sbin:/sbin $chroot /mnt \
            rpm -iv --nosignature ${lib.optionalString (!runScripts) "--noscripts"} $rpms

          echo "running post-install script..."
          eval "$postInstall"

          rm /mnt/.debug

          ${util-linux}/bin/umount /mnt${storeDir} /mnt/tmp /mnt/dev ${lib.optionalString unifiedSystemDir "/mnt/proc"}
          ${util-linux}/bin/umount /mnt
        '';

        passthru = { inherit fullName; };
      }
    );