message: nydus-test: restore chunk dict test
  This partly reverts to get back the chunk dict test.
diff: @@ -252,6 +252,90 @@ def test_upload_oss(
  oss.rm(b)
  +@pytest.mark.parametrize(
  + "fs_version,source,chunk_dict_arg",
  + [
  + (
  + 5,
  + "memcached:latest",
  + "bootstrap:registry:ghcr.io/dragonflyoss/image-service/nydus-build-cache:memcached-v5"
  + ),
  + (
  + 6,
  + "memcached:latest",
  + "bootstrap:registry:ghcr.io/dragonflyoss/image-service/nydus-build-cache:memcached-v6"
  + )
  + ]
  +)
  +def test_chunk_dict(
  + nydus_anchor: NydusAnchor,
  + rafs_conf: RafsConf,
  + source,
  + chunk_dict_arg,
  + local_registry,
  + nydusify_converter,
  +):
  + '''
  + only support oss backend now
  + - convert image with chunk-dict
  + - check new image
  + '''
  + converter = Nydusify(nydus_anchor)
  +
  + time.sleep(1)
  +
  + oss_prefix = "nydus_v2/"
  +
  + converter.docker_v2().backend_type(
  + "oss", oss_object_prefix=oss_prefix
  + ).build_cache_ref(
  + "localhost:5000/build_cache:000"
  + ).force_push().chunk_dict(chunk_dict_arg).convert(source, fs_version=fs_version)
  +
  + rafs_conf.set_rafs_backend(Backend.OSS, prefix=oss_prefix)
  + rafs_conf.enable_fs_prefetch()
  + rafs_conf.enable_rafs_blobcache()
  + rafs_conf.dump_rafs_conf()
  +
  + bootstrap = converter.locate_bootstrap()
  +
  + checker = Nydusify(nydus_anchor)
  + checker.backend_type(
  + "oss", oss_object_prefix=oss_prefix
  + ).with_new_work_dir(
  + nydus_anchor.nydusify_work_dir+'-check'
  + ).check(source)
  +
  + converted_layers = converter.extract_converted_layers_names()
  +
  + # With oss backend, ant useage, `layers` only has one member
  + records = converter.get_build_cache_records("localhost:5000/build_cache:000")
  + assert len(records) != 0
  + cached_layers = [c["digest"] for c in records]
  + assert cached_layers.sort() == converted_layers.sort()
  +
  + pulled_bootstrap = converter.pull_bootstrap(
  + tempfile.TemporaryDirectory(
  + dir=nydus_anchor.workspace, suffix="bootstrap"
  + ).name,
  + "pulled_bootstrap",
  + )
  +
  + # Mount source rootfs (ociv1)
  + layers, base = converter.extract_source_layers_names_and_download()
  + nydus_anchor.mount_overlayfs(layers, base)
  + # Mount rafs rootfs
  + rafs = RafsMount(nydus_anchor, None, rafs_conf)
  +
  + workload_gen = WorkloadGen(nydus_anchor.mount_point, nydus_anchor.overlayfs)
  + rafs.thread_num(6).bootstrap(pulled_bootstrap).prefetch_files("/").mount()
  +
  + assert workload_gen.verify_entire_fs()
  + workload_gen.setup_workload_generator()
  + workload_gen.torture_read(8, 12, verify=True)
  + workload_gen.finish_torture_read()
  +
  +
  @pytest.mark.parametrize(
  "source",
  [
  