def main()

in src/markov/training_worker.py [0:0]


def main():
    screen.set_use_colors(False)

    parser = argparse.ArgumentParser()
    parser.add_argument('-pk', '--preset_s3_key',
                        help="(string) Name of a preset to download from S3",
                        type=str,
                        required=False)
    parser.add_argument('-ek', '--environment_s3_key',
                        help="(string) Name of an environment file to download from S3",
                        type=str,
                        required=False)
    parser.add_argument('--model_metadata_s3_key',
                        help="(string) Model Metadata File S3 Key",
                        type=str)
    parser.add_argument('-c', '--checkpoint_dir',
                        help='(string) Path to a folder containing a checkpoint to write the model to.',
                        type=str,
                        default='./checkpoint_sagemaker')
    parser.add_argument('--pretrained_checkpoint_dir',
                        help='(string) Path to a folder for downloading a pre-trained model',
                        type=str,
                        default=PRETRAINED_MODEL_DIR)
    parser.add_argument('--s3_bucket',
                        help='(string) S3 bucket',
                        type=str,
                        default=os.environ.get("SAGEMAKER_SHARED_S3_BUCKET", "sagemaker-s3"))
    parser.add_argument('--s3_prefix',
                        help='(string) S3 prefix',
                        type=str,
                        default='sagemaker')
    parser.add_argument('--framework',
                        help='(string) tensorflow or mxnet',
                        type=str,
                        default='tensorflow')
    parser.add_argument('--pretrained_s3_bucket',
                        help='(string) S3 bucket for pre-trained model',
                        type=str)
    parser.add_argument('--pretrained_s3_prefix',
                        help='(string) S3 prefix for pre-trained model',
                        type=str,
                        default='sagemaker')
    parser.add_argument('--aws_region',
                        help='(string) AWS region',
                        type=str,
                        default=os.environ.get("AWS_REGION", "us-east-1"))

    args, _ = parser.parse_known_args()
    logger.info("Training Worker Args: %s" % args)

    s3_client = S3Client(region_name=args.aws_region, max_retry_attempts=0)

    # download model metadata
    # TODO: replace 'agent' with name of each agent
    model_metadata_download = ModelMetadata(bucket=args.s3_bucket,
                                            s3_key=args.model_metadata_s3_key,
                                            region_name=args.aws_region,
                                            local_path=MODEL_METADATA_LOCAL_PATH_FORMAT.format('agent'))
    model_metadata_info = model_metadata_download.get_model_metadata_info()
    network_type = model_metadata_info[ModelMetadataKeys.NEURAL_NETWORK.value]
    version = model_metadata_info[ModelMetadataKeys.VERSION.value]

    # upload model metadata
    model_metadata_upload = ModelMetadata(bucket=args.s3_bucket,
                                          s3_key=get_s3_key(args.s3_prefix, MODEL_METADATA_S3_POSTFIX),
                                          region_name=args.aws_region,
                                          local_path=MODEL_METADATA_LOCAL_PATH_FORMAT.format('agent'))
    model_metadata_upload.persist(s3_kms_extra_args=utils.get_s3_kms_extra_args())

    shutil.copy2(model_metadata_download.local_path, SM_MODEL_OUTPUT_DIR)

    success_custom_preset = False
    if args.preset_s3_key:
        preset_local_path = "./markov/presets/preset.py"
        try:
            s3_client.download_file(bucket=args.s3_bucket,
                                    s3_key=args.preset_s3_key,
                                    local_path=preset_local_path)
            success_custom_preset = True
        except botocore.exceptions.ClientError:
            pass
        if not success_custom_preset:
            logger.info("Could not download the preset file. Using the default DeepRacer preset.")
        else:
            preset_location = "markov.presets.preset:graph_manager"
            graph_manager = short_dynamic_import(preset_location, ignore_module_case=True)
            s3_client.upload_file(bucket=args.s3_bucket,
                                  s3_key=os.path.normpath("%s/presets/preset.py" % args.s3_prefix),
                                  local_path=preset_local_path,
                                  s3_kms_extra_args=utils.get_s3_kms_extra_args())
            if success_custom_preset:
                logger.info("Using preset: %s" % args.preset_s3_key)

    if not success_custom_preset:
        params_blob = os.environ.get('SM_TRAINING_ENV', '')
        if params_blob:
            params = json.loads(params_blob)
            sm_hyperparams_dict = params["hyperparameters"]
        else:
            sm_hyperparams_dict = {}

        #! TODO each agent should have own config
        agent_config = {'model_metadata': model_metadata_download,
                        ConfigParams.CAR_CTRL_CONFIG.value: {ConfigParams.LINK_NAME_LIST.value: [],
                                                             ConfigParams.VELOCITY_LIST.value: {},
                                                             ConfigParams.STEERING_LIST.value: {},
                                                             ConfigParams.CHANGE_START.value: None,
                                                             ConfigParams.ALT_DIR.value: None,
                                                             ConfigParams.MODEL_METADATA.value : model_metadata_download,
                                                             ConfigParams.REWARD.value: None,
                                                             ConfigParams.AGENT_NAME.value: 'racecar'}}

        agent_list = list()
        agent_list.append(create_training_agent(agent_config))

        graph_manager, robomaker_hyperparams_json = get_graph_manager(hp_dict=sm_hyperparams_dict,
                                                                      agent_list=agent_list,
                                                                      run_phase_subject=None,
                                                                      run_type=str(RunType.TRAINER))

        # Upload hyperparameters to SageMaker shared s3 bucket
        hyperparameters = Hyperparameters(bucket=args.s3_bucket,
                                          s3_key=get_s3_key(args.s3_prefix, HYPERPARAMETER_S3_POSTFIX),
                                          region_name=args.aws_region)
        hyperparameters.persist(hyperparams_json=robomaker_hyperparams_json,
                                s3_kms_extra_args=utils.get_s3_kms_extra_args())

        # Attach sample collector to graph_manager only if sample count > 0
        max_sample_count = int(sm_hyperparams_dict.get("max_sample_count", 0))
        if max_sample_count > 0:
            sample_collector = SampleCollector(bucket=args.s3_bucket,
                                               s3_prefix=args.s3_prefix,
                                               region_name=args.aws_region,
                                               max_sample_count=max_sample_count,
                                               sampling_frequency=int(sm_hyperparams_dict.get("sampling_frequency", 1)))
            graph_manager.sample_collector = sample_collector

    # persist IP config from sagemaker to s3
    ip_config = IpConfig(bucket=args.s3_bucket,
                         s3_prefix=args.s3_prefix,
                         region_name=args.aws_region)
    ip_config.persist(s3_kms_extra_args=utils.get_s3_kms_extra_args())

    training_algorithm = model_metadata_download.training_algorithm
    output_head_format = FROZEN_HEAD_OUTPUT_GRAPH_FORMAT_MAPPING[training_algorithm]

    use_pretrained_model = args.pretrained_s3_bucket and args.pretrained_s3_prefix
    # Handle backward compatibility
    if use_pretrained_model:
        # checkpoint s3 instance for pretrained model
        # TODO: replace 'agent' for multiagent training
        checkpoint = Checkpoint(bucket=args.pretrained_s3_bucket,
                                s3_prefix=args.pretrained_s3_prefix,
                                region_name=args.aws_region,
                                agent_name='agent',
                                checkpoint_dir=args.pretrained_checkpoint_dir,
                                output_head_format=output_head_format)
        # make coach checkpoint compatible
        if version < SIMAPP_VERSION_2 and not checkpoint.rl_coach_checkpoint.is_compatible():
            checkpoint.rl_coach_checkpoint.make_compatible(checkpoint.syncfile_ready)
        # get best model checkpoint string
        model_checkpoint_name = checkpoint.deepracer_checkpoint_json.get_deepracer_best_checkpoint()
        # Select the best checkpoint model by uploading rl coach .coach_checkpoint file
        checkpoint.rl_coach_checkpoint.update(
            model_checkpoint_name=model_checkpoint_name,
            s3_kms_extra_args=utils.get_s3_kms_extra_args())
        # add checkpoint into checkpoint_dict
        checkpoint_dict = {'agent': checkpoint}
        # load pretrained model
        ds_params_instance_pretrained = S3BotoDataStoreParameters(checkpoint_dict=checkpoint_dict)
        data_store_pretrained = S3BotoDataStore(ds_params_instance_pretrained, graph_manager, True)
        data_store_pretrained.load_from_store()

    memory_backend_params = DeepRacerRedisPubSubMemoryBackendParameters(redis_address="localhost",
                                                                        redis_port=6379,
                                                                        run_type=str(RunType.TRAINER),
                                                                        channel=args.s3_prefix,
                                                                        network_type=network_type)

    graph_manager.memory_backend_params = memory_backend_params

    # checkpoint s3 instance for training model
    checkpoint = Checkpoint(bucket=args.s3_bucket,
                            s3_prefix=args.s3_prefix,
                            region_name=args.aws_region,
                            agent_name='agent',
                            checkpoint_dir=args.checkpoint_dir,
                            output_head_format=output_head_format)
    checkpoint_dict = {'agent': checkpoint}
    ds_params_instance = S3BotoDataStoreParameters(checkpoint_dict=checkpoint_dict)

    graph_manager.data_store_params = ds_params_instance

    graph_manager.data_store = S3BotoDataStore(ds_params_instance, graph_manager)

    task_parameters = TaskParameters()
    task_parameters.experiment_path = SM_MODEL_OUTPUT_DIR
    task_parameters.checkpoint_save_secs = 20
    if use_pretrained_model:
        task_parameters.checkpoint_restore_path = args.pretrained_checkpoint_dir
    task_parameters.checkpoint_save_dir = args.checkpoint_dir

    training_worker(
        graph_manager=graph_manager,
        task_parameters=task_parameters,
        user_batch_size=json.loads(robomaker_hyperparams_json)["batch_size"],
        user_episode_per_rollout=json.loads(robomaker_hyperparams_json)["num_episodes_between_training"],
        training_algorithm=training_algorithm
    )