feature: add support for SageMaker workflow tuning step

src/sagemaker/session.py

@@ -2033,6 +2033,45 @@ def create_tuning_job(
                 "Only one of training_config and training_config_list should be provided."
             )
 
+        tune_request = self._get_tuning_request(
+            job_name=job_name,
+            tuning_config=tuning_config,
+            training_config=training_config,
+            training_config_list=training_config_list,
+            warm_start_config=warm_start_config,
+            tags=tags,
+        )
+
+        LOGGER.info("Creating hyperparameter tuning job with name: %s", job_name)
+        LOGGER.debug("tune request: %s", json.dumps(tune_request, indent=4))
+        self.sagemaker_client.create_hyper_parameter_tuning_job(**tune_request)
+
+    def _get_tuning_request(
+        self,
+        job_name,
+        tuning_config,
+        training_config=None,
+        training_config_list=None,
+        warm_start_config=None,
+        tags=None,
+    ):
+        """Construct CreateHyperParameterTuningJob request
+
+        Args:
+            job_name (str): Name of the tuning job being created.
+            tuning_config (dict): Configuration to launch the tuning job.
+            training_config (dict): Configuration to launch training jobs under the tuning job
+                using a single algorithm.
+            training_config_list (list[dict]): A list of configurations to launch training jobs
+                under the tuning job using one or multiple algorithms. Either training_config
+                or training_config_list should be provided, but not both.
+            warm_start_config (dict): Configuration defining the type of warm start and
+                other required configurations.
+            tags (list[dict]): List of tags for labeling the tuning job. For more, see
+                https://docs.aws.amazon.com/sagemaker/latest/dg/API_Tag.html.
+        Returns:
+            dict: A dictionary for CreateHyperParameterTuningJob request
+        """
         tune_request = {
             "HyperParameterTuningJobName": job_name,
             "HyperParameterTuningJobConfig": self._map_tuning_config(**tuning_config),
@@ -2053,9 +2092,7 @@ def create_tuning_job(
         if tags is not None:
             tune_request["Tags"] = tags
 
-        LOGGER.info("Creating hyperparameter tuning job with name: %s", job_name)
-        LOGGER.debug("tune request: %s", json.dumps(tune_request, indent=4))
-        self.sagemaker_client.create_hyper_parameter_tuning_job(**tune_request)
+        return tune_request
 
     def describe_tuning_job(self, job_name):
         """Calls DescribeHyperParameterTuningJob API for the given job name, returns the response.

src/sagemaker/tuner.py

@@ -346,7 +346,9 @@ def _prepare_static_hyperparameters_for_tuning(self, include_cls_metadata=False)
                 estimator_name: self._prepare_static_hyperparameters(
                     estimator,
                     self._hyperparameter_ranges_dict[estimator_name],
-                    include_cls_metadata.get(estimator_name, False),
+                    include_cls_metadata.get(estimator_name, False)
+                    if isinstance(include_cls_metadata, dict)
+                    else include_cls_metadata,
                 )
                 for (estimator_name, estimator) in self.estimator_dict.items()
             }
@@ -1460,6 +1462,23 @@ def start_new(cls, tuner, inputs):
             sagemaker.tuner._TuningJob: Constructed object that captures all
             information about the started job.
         """
+        tuner_args = cls._get_tuner_args(tuner, inputs)
+        tuner.sagemaker_session.create_tuning_job(**tuner_args)
+
+        return cls(tuner.sagemaker_session, tuner._current_job_name)
+
+    @classmethod
+    def _get_tuner_args(cls, tuner, inputs):
+        """Gets a dict of arguments for a new Amazon SageMaker tuning job from the tuner
+
+        Args:
+            tuner (:class:`~sagemaker.tuner.HyperparameterTuner`):
+                The ``HyperparameterTuner`` instance that started the job.
+            inputs: Information about the training data. Please refer to the
+            ``fit()`` method of the associated estimator.
+        Returns:
+            Dict: dict for `sagemaker.session.Session.tune` method
+        """
         warm_start_config_req = None
         if tuner.warm_start_config:
             warm_start_config_req = tuner.warm_start_config.to_input_req()
@@ -1506,8 +1525,7 @@ def start_new(cls, tuner, inputs):
                 for estimator_name in sorted(tuner.estimator_dict.keys())
             ]
 
-        tuner.sagemaker_session.create_tuning_job(**tuner_args)
-        return cls(tuner.sagemaker_session, tuner._current_job_name)
+        return tuner_args
 
     @staticmethod
     def _prepare_training_config(

src/sagemaker/workflow/properties.py

@@ -13,7 +13,7 @@
 """The properties definitions for workflow."""
 from __future__ import absolute_import
 
-from typing import Dict, Union
+from typing import Dict, Union, List
 
 import attr
 
@@ -40,27 +40,35 @@ def __new__(mcs, *args, **kwargs):
 class Properties(metaclass=PropertiesMeta):
     """Properties for use in workflow expressions."""
 
-    def __init__(self, path: str, shape_name: str = None):
+    def __init__(
+        self,
+        path: str,
+        shape_name: str = None,
+        shape_names: List[str] = None,
+    ):
         """Create a Properties instance representing the given shape.
 
         Args:
             path (str): The parent path of the Properties instance.
             shape_name (str): The botocore sagemaker service model shape name.
+            shape_names (str): A List of the botocore sagemaker service model shape name.
         """
         self._path = path
-        self._shape_name = shape_name
-
-        shape = Properties._shapes.get(self._shape_name, {})
-        shape_type = shape.get("type")
-        if shape_type in Properties._primitive_types:
-            self.__str__ = shape_name
-        elif shape_type == "structure":
-            members = shape["members"]
-            for key, info in members.items():
-                if Properties._shapes.get(info["shape"], {}).get("type") == "list":
-                    self.__dict__[key] = PropertiesList(f"{path}.{key}", info["shape"])
-                else:
-                    self.__dict__[key] = Properties(f"{path}.{key}", info["shape"])
+        shape_names = [] if shape_names is None else shape_names
+        self._shape_names = shape_names if shape_name is None else [shape_name] + shape_names
+
+        for name in self._shape_names:
+            shape = Properties._shapes.get(name, {})
+            shape_type = shape.get("type")
+            if shape_type in Properties._primitive_types:
+                self.__str__ = name
+            elif shape_type == "structure":
+                members = shape["members"]
+                for key, info in members.items():
+                    if Properties._shapes.get(info["shape"], {}).get("type") == "list":
+                        self.__dict__[key] = PropertiesList(f"{path}.{key}", info["shape"])
+                    else:
+                        self.__dict__[key] = Properties(f"{path}.{key}", info["shape"])
 
     @property
     def expr(self):
@@ -77,8 +85,10 @@ def __init__(self, path: str, shape_name: str = None):
         Args:
             path (str): The parent path of the PropertiesList instance.
             shape_name (str): The botocore sagemaker service model shape name.
+            root_shape_name (str): The botocore sagemaker service model shape name.
         """
         super(PropertiesList, self).__init__(path, shape_name)
+        self.shape_name = shape_name
         self._items: Dict[Union[int, str], Properties] = dict()
 
     def __getitem__(self, item: Union[int, str]):
@@ -88,7 +98,7 @@ def __getitem__(self, item: Union[int, str]):
             item (Union[int, str]): The index of the item in sequence.
         """
         if item not in self._items.keys():
-            shape = Properties._shapes.get(self._shape_name)
+            shape = Properties._shapes.get(self.shape_name)
             member = shape["member"]["shape"]
             if isinstance(item, str):
                 property_item = Properties(f"{self._path}['{item}']", member)

src/sagemaker/workflow/steps.py

@@ -30,6 +30,7 @@
     Processor,
 )
 from sagemaker.transformer import Transformer, _TransformJob
+from sagemaker.tuner import HyperparameterTuner, _TuningJob
 from sagemaker.workflow.entities import (
     DefaultEnumMeta,
     Entity,
@@ -39,6 +40,7 @@
     PropertyFile,
     Properties,
 )
+from sagemaker.workflow.functions import Join
 
 
 class StepTypeEnum(Enum, metaclass=DefaultEnumMeta):
@@ -51,6 +53,7 @@ class StepTypeEnum(Enum, metaclass=DefaultEnumMeta):
     TRAINING = "Training"
     TRANSFORM = "Transform"
     CALLBACK = "Callback"
+    TUNING = "Tuning"
 
 
 @attr.s
@@ -92,6 +95,7 @@ def add_depends_on(self, step_names: List[str]):
         """Add step names to the current step depends on list"""
         if not step_names:
             return
+
         if not self.depends_on:
             self.depends_on = []
         self.depends_on.extend(step_names)
@@ -429,3 +433,132 @@ def to_request(self) -> RequestType:
                 property_file.expr for property_file in self.property_files
             ]
         return request_dict
+
+
+class TuningStep(Step):
+    """Tuning step for workflow."""
+
+    def __init__(
+        self,
+        name: str,
+        tuner: HyperparameterTuner,
+        inputs=None,
+        job_arguments: List[str] = None,
+        cache_config: CacheConfig = None,
+        depends_on: List[str] = None,
+    ):
+        """Construct a TuningStep, given a `HyperparameterTuner` instance.
+
+        In addition to the tuner instance, the other arguments are those that are supplied to
+        the `fit` method of the `sagemaker.tuner.HyperparameterTuner`.
+
+        Args:
+            name (str): The name of the tuning step.
+            tuner (HyperparameterTuner): A `sagemaker.tuner.HyperparameterTuner` instance.
+            inputs: Information about the training data. Please refer to the
+                ``fit()`` method of the associated estimator, as this can take
+                any of the following forms:
+
+                * (str) - The S3 location where training data is saved.
+                * (dict[str, str] or dict[str, sagemaker.inputs.TrainingInput]) -
+                    If using multiple channels for training data, you can specify
+                    a dict mapping channel names to strings or
+                    :func:`~sagemaker.inputs.TrainingInput` objects.
+                * (sagemaker.inputs.TrainingInput) - Channel configuration for S3 data sources
+                    that can provide additional information about the training dataset.
+                    See :func:`sagemaker.inputs.TrainingInput` for full details.
+                * (sagemaker.session.FileSystemInput) - channel configuration for
+                    a file system data source that can provide additional information as well as
+                    the path to the training dataset.
+                * (sagemaker.amazon.amazon_estimator.RecordSet) - A collection of
+                    Amazon :class:~`Record` objects serialized and stored in S3.
+                    For use with an estimator for an Amazon algorithm.
+                * (sagemaker.amazon.amazon_estimator.FileSystemRecordSet) -
+                    Amazon SageMaker channel configuration for a file system data source for
+                    Amazon algorithms.
+                * (list[sagemaker.amazon.amazon_estimator.RecordSet]) - A list of
+                    :class:~`sagemaker.amazon.amazon_estimator.RecordSet` objects,
+                    where each instance is a different channel of training data.
+                * (list[sagemaker.amazon.amazon_estimator.FileSystemRecordSet]) - A list of
+                    :class:~`sagemaker.amazon.amazon_estimator.FileSystemRecordSet` objects,
+                    where each instance is a different channel of training data.
+            job_arguments (List[str]): A list of strings to be passed into the processing job.
+                Defaults to `None`.
+            cache_config (CacheConfig):  A `sagemaker.workflow.steps.CacheConfig` instance.
+            depends_on (List[str]): A list of step names this `sagemaker.workflow.steps.ProcessingStep`
+                depends on
+        """
+        super(TuningStep, self).__init__(name, StepTypeEnum.TUNING, depends_on)
+        self.tuner = tuner
+        self.inputs = inputs
+        self.job_arguments = job_arguments
+        self._properties = Properties(
+            path=f"Steps.{name}",
+            shape_names=[
+                "DescribeHyperParameterTuningJobResponse",
+                "ListTrainingJobsForHyperParameterTuningJobResponse",
+            ],
+        )
+        self.cache_config = cache_config
+
+    @property
+    def arguments(self) -> RequestType:
+        """The arguments dict that is used to call `create_hyper_parameter_tuning_job`.
+
+        NOTE: The CreateHyperParameterTuningJob request is not quite the
+            args list that workflow needs.
+        The HyperParameterTuningJobName attribute cannot be included.
+        """
+        if self.tuner.estimator is not None:
+            self.tuner.estimator._prepare_for_training()
+        else:
+            for _, estimator in self.tuner.estimator_dict.items():
+                estimator._prepare_for_training()
+
+        self.tuner._prepare_for_tuning()
+        tuner_args = _TuningJob._get_tuner_args(self.tuner, self.inputs)
+        request_dict = self.tuner.sagemaker_session._get_tuning_request(**tuner_args)
+        request_dict.pop("HyperParameterTuningJobName")
+
+        return request_dict
+
+    @property
+    def properties(self):
+        """A Properties object representing
+
+        `DescribeHyperParameterTuningJobResponse` and
+        `ListTrainingJobsForHyperParameterTuningJobResponse` data model.
+        """
+        return self._properties
+
+    def to_request(self) -> RequestType:
+        """Updates the dictionary with cache configuration."""
+        request_dict = super().to_request()
+        if self.cache_config:
+            request_dict.update(self.cache_config.config)
+
+        return request_dict
+
+    def get_top_model_s3_uri(self, top_k: int, s3_bucket: str, prefix: str = ""):
+        """Get the model artifact s3 uri from the top performing training jobs.
+
+        Args:
+            top_k (int): the index of the top performing training job
+                tuning step stores up to 50 top performing training jobs, hence
+                a valid top_k value is from 0 to 49. The best training job
+                model is at index 0
+            s3_bucket (str): the s3 bucket to store the training job output artifact
+            prefix (str): the s3 key prefix to store the training job output artifact
+        """
+        values = ["s3:/", s3_bucket]
+        if prefix != "" and prefix is not None:
+            values.append(prefix)
+
+        return Join(
+            on="/",
+            values=values
+            + [
+                self.properties.TrainingJobSummaries[top_k].TrainingJobName,
+                "output/model.tar.gz",
+            ],
+        )

tests/data/pytorch_mnist/mnist.py

@@ -182,7 +182,7 @@ def train(args):
         accuracy = test(model, test_loader, device)
     save_model(model, args.model_dir)
 
-    logger.debug("Overall test accuracy: {}".format(accuracy))
+    logger.debug("Overall test accuracy: {};".format(accuracy))
 
 
 def test(model, test_loader, device):