[Core feature] Flytekit should support unsafe mode for types

flytekit/core/interface.py

@@ -384,6 +384,7 @@ def transform_function_to_interface(
     fn: typing.Callable,
     docstring: Optional[Docstring] = None,
     is_reference_entity: bool = False,
+    pickle_untyped: bool = False,
 ) -> Interface:
     """
     From the annotations on a task function that the user should have provided, and the output names they want to use
@@ -395,6 +396,9 @@ def transform_function_to_interface(
     type_hints = get_type_hints(fn, include_extras=True)
     signature = inspect.signature(fn)
     return_annotation = type_hints.get("return", None)
+    # If the return annotation is None and the pickle_untyped is True, we will use it as Any
+    if return_annotation is None and pickle_untyped:
+        return_annotation = Any
 
     ctx = FlyteContextManager.current_context()
 
@@ -420,7 +424,10 @@ def transform_function_to_interface(
     for k, v in signature.parameters.items():  # type: ignore
         annotation = type_hints.get(k, None)
         if annotation is None:
-            raise FlyteMissingTypeException(fn=fn, param_name=k)
+            if not pickle_untyped:
+                raise FlyteMissingTypeException(fn=fn, param_name=k)
+            # If the pickle_untyped is True, we will use it as Any
+            annotation = Any
         default = v.default if v.default is not inspect.Parameter.empty else None
         # Inputs with default values are currently ignored, we may want to look into that in the future
         inputs[k] = (annotation, default)  # type: ignore

flytekit/core/python_function_task.py

@@ -112,6 +112,7 @@ def __init__(
         node_dependency_hints: Optional[
             Iterable[Union["PythonFunctionTask", "_annotated_launch_plan.LaunchPlan", WorkflowBase]]
         ] = None,
+        pickle_untyped: bool = False,
         **kwargs,
     ):
         """
@@ -125,10 +126,15 @@ def __init__(
         :param Optional[Iterable[Union["PythonFunctionTask", "_annotated_launch_plan.LaunchPlan", WorkflowBase]]] node_dependency_hints:
             A list of tasks, launchplans, or workflows that this task depends on. This is only
             for dynamic tasks/workflows, where flyte cannot automatically determine the dependencies prior to runtime.
+        :param bool pickle_untyped: If set to True, the task will pickle untyped outputs. This is just a convenience
+            flag to avoid having to specify the output types in the interface. This is not recommended for production
+            use.
         """
         if task_function is None:
             raise ValueError("TaskFunction is a required parameter for PythonFunctionTask")
-        self._native_interface = transform_function_to_interface(task_function, Docstring(callable_=task_function))
+        self._native_interface = transform_function_to_interface(
+            task_function, Docstring(callable_=task_function), pickle_untyped=pickle_untyped
+        )
         mutated_interface = self._native_interface.remove_inputs(ignore_input_vars)
         name, _, _, _ = extract_task_module(task_function)
         super().__init__(

flytekit/core/task.py

@@ -130,6 +130,7 @@ def task(
     pod_template: Optional["PodTemplate"] = ...,
     pod_template_name: Optional[str] = ...,
     accelerator: Optional[BaseAccelerator] = ...,
+    pickle_untyped: bool = ...,
 ) -> Callable[[Callable[..., FuncOut]], PythonFunctionTask[T]]: ...
 
 
@@ -168,6 +169,7 @@ def task(
     pod_template: Optional["PodTemplate"] = ...,
     pod_template_name: Optional[str] = ...,
     accelerator: Optional[BaseAccelerator] = ...,
+    pickle_untyped: bool = ...,
 ) -> Union[Callable[P, FuncOut], PythonFunctionTask[T]]: ...
 
 
@@ -211,6 +213,7 @@ def task(
     pod_template: Optional["PodTemplate"] = None,
     pod_template_name: Optional[str] = None,
     accelerator: Optional[BaseAccelerator] = None,
+    pickle_untyped: bool = False,
 ) -> Union[
     Callable[P, FuncOut],
     Callable[[Callable[P, FuncOut]], PythonFunctionTask[T]],
@@ -340,6 +343,7 @@ def launch_dynamically():
     :param pod_template: Custom PodTemplate for this task.
     :param pod_template_name: The name of the existing PodTemplate resource which will be used in this task.
     :param accelerator: The accelerator to use for this task.
+    :param pickle_untyped: Boolean that indicates if the task allows unspecified data types.
     """
 
     def wrapper(fn: Callable[P, Any]) -> PythonFunctionTask[T]:
@@ -375,6 +379,7 @@ def wrapper(fn: Callable[P, Any]) -> PythonFunctionTask[T]:
             pod_template=pod_template,
             pod_template_name=pod_template_name,
             accelerator=accelerator,
+            pickle_untyped=pickle_untyped,
         )
         update_wrapper(task_instance, decorated_fn)
         return task_instance

flytekit/core/type_engine.py

@@ -1285,7 +1285,12 @@ def to_literal_checks(cls, python_val: typing.Any, python_type: Type[T], expecte
                 "actual attribute that you want to use. For example, in NamedTuple('OP', x=int) then"
                 "return v.x, instead of v, even if this has a single element"
             )
-        if (python_val is None and python_type != type(None)) and expected and expected.union_type is None:
+        if (
+            (python_val is None and python_type != type(None))
+            and expected
+            and expected.union_type is None
+            and python_type is not Any
+        ):
             raise TypeTransformerFailedError(f"Python value cannot be None, expected {python_type}/{expected}")
 
     @classmethod

flytekit/core/workflow.py

@@ -668,11 +668,14 @@ def __init__(
         docstring: Optional[Docstring] = None,
         on_failure: Optional[Union[WorkflowBase, Task]] = None,
         docs: Optional[Documentation] = None,
+        pickle_untyped: bool = False,
         default_options: Optional[Options] = None,
     ):
         name, _, _, _ = extract_task_module(workflow_function)
         self._workflow_function = workflow_function
-        native_interface = transform_function_to_interface(workflow_function, docstring=docstring)
+        native_interface = transform_function_to_interface(
+            workflow_function, docstring=docstring, pickle_untyped=pickle_untyped
+        )
 
         # TODO do we need this - can this not be in launchplan only?
         #    This can be in launch plan only, but is here only so that we don't have to re-evaluate. Or
@@ -837,6 +840,7 @@ def workflow(
     interruptible: bool = ...,
     on_failure: Optional[Union[WorkflowBase, Task]] = ...,
     docs: Optional[Documentation] = ...,
+    pickle_untyped: bool = ...,
     default_options: Optional[Options] = ...,
 ) -> Callable[[Callable[..., FuncOut]], PythonFunctionWorkflow]: ...
 
@@ -848,6 +852,7 @@ def workflow(
     interruptible: bool = ...,
     on_failure: Optional[Union[WorkflowBase, Task]] = ...,
     docs: Optional[Documentation] = ...,
+    pickle_untyped: bool = ...,
     default_options: Optional[Options] = ...,
 ) -> Union[Callable[P, FuncOut], PythonFunctionWorkflow]: ...
 
@@ -858,6 +863,7 @@ def workflow(
     interruptible: bool = False,
     on_failure: Optional[Union[WorkflowBase, Task]] = None,
     docs: Optional[Documentation] = None,
+    pickle_untyped: bool = False,
     default_options: Optional[Options] = None,
 ) -> Union[Callable[P, FuncOut], Callable[[Callable[P, FuncOut]], PythonFunctionWorkflow], PythonFunctionWorkflow]:
     """
@@ -890,6 +896,8 @@ def workflow(
     :param on_failure: Invoke this workflow or task on failure. The Workflow / task has to match the signature of
          the current workflow, with an additional parameter called `error` Error
     :param docs: Description entity for the workflow
+    :param pickle_untyped: This is a flag that allows users to bypass the type-checking that Flytekit does when constructing
+         the workflow. This is not recommended for general use.
     :param default_options: Default options for the workflow when creating a default launch plan. Currently only
          the labels and annotations are allowed to be set as defaults.
     """
@@ -906,6 +914,7 @@ def wrapper(fn: Callable[P, FuncOut]) -> PythonFunctionWorkflow:
             docstring=Docstring(callable_=fn),
             on_failure=on_failure,
             docs=docs,
+            pickle_untyped=pickle_untyped,
             default_options=default_options,
         )
         update_wrapper(workflow_instance, fn)

flytekit/types/pickle/pickle.py

@@ -78,7 +78,11 @@ async def async_to_python_value(self, ctx: FlyteContext, lv: Literal, expected_p
         return await FlytePickle.from_pickle(uri)
 
     async def async_to_literal(
-        self, ctx: FlyteContext, python_val: T, python_type: Type[T], expected: LiteralType
+        self,
+        ctx: FlyteContext,
+        python_val: T,
+        python_type: Type[T],
+        expected: LiteralType,
     ) -> Literal:
         if python_val is None:
             raise AssertionError("Cannot pickle None Value.")

tests/flytekit/unit/core/test_type_hints.py

@@ -20,8 +20,7 @@
 import flytekit
 import flytekit.configuration
 from flytekit import Secret, SQLTask, dynamic, kwtypes, map_task
-from flytekit.configuration import (FastSerializationSettings, Image,
-                                    ImageConfig)
+from flytekit.configuration import FastSerializationSettings, Image, ImageConfig
 from flytekit.core import context_manager, launch_plan, promise
 from flytekit.core.condition import conditional
 from flytekit.core.constants import MESSAGEPACK
@@ -33,11 +32,18 @@
 from flytekit.core.resources import Resources
 from flytekit.core.task import TaskMetadata, task
 from flytekit.core.testing import patch, task_mock
-from flytekit.core.type_engine import (RestrictedTypeError, SimpleTransformer,
-                                       TypeEngine, TypeTransformerFailedError)
+from flytekit.core.type_engine import (
+    RestrictedTypeError,
+    SimpleTransformer,
+    TypeEngine,
+    TypeTransformerFailedError,
+)
 from flytekit.core.workflow import workflow
-from flytekit.exceptions.user import (FlyteFailureNodeInputMismatchException,
-                                      FlyteValidationException)
+from flytekit.exceptions.user import (
+    FlyteFailureNodeInputMismatchException,
+    FlyteValidationException,
+    FlyteMissingTypeException,
+)
 from flytekit.models import literals as _literal_models
 from flytekit.models.core import types as _core_types
 from flytekit.models.interface import Parameter
@@ -2207,3 +2213,105 @@ def my_wf(a: int, retries: int) -> int:
 
     with pytest.raises(AssertionError):
         my_wf(a=1, retries=1)
+
+
+def test_pickle_untyped_input_wf_and_task():
+    @task(pickle_untyped=True)
+    def t1(a) -> int:
+        if type(a) == int:
+            return a + 1
+        return 0
+
+    with pytest.raises(FlyteMissingTypeException):
+
+        @task
+        def t2_wo_pickle_untyped(a) -> int:
+            return a + 1
+
+    @workflow(pickle_untyped=True)
+    def wf1_with_pickle_untyped(a) -> int:
+        return t1(a=a)
+
+    assert wf1_with_pickle_untyped(a=1) == 2
+    assert wf1_with_pickle_untyped(a="1") == 0
+
+    with pytest.raises(FlyteMissingTypeException):
+
+        @workflow
+        def wf1_wo_pickle_untyped(a) -> int:
+            return t1(a=a)
+
+
+def test_pickle_untyped_wf_and_task():
+    @task(pickle_untyped=True)
+    def t1(a):
+        if type(a) != int:
+            return "t1"
+        return a + 1
+
+    @task(pickle_untyped=True)
+    def t2(a):
+        if type(a) != int:
+            return "t2"
+        return a + 2
+
+    @workflow(pickle_untyped=True)
+    def wf1_with_pickle_untyped(a):
+        a1 = t1(a=a)
+        return t2(a=a1)
+
+    assert wf1_with_pickle_untyped(a=1) == 4
+    assert wf1_with_pickle_untyped(a="1") == "t2"
+
+
+def test_wf_with_pickle_untyped_and_regular_tasks():
+    @task(pickle_untyped=True)
+    def t1(a):
+        if type(a) != int:
+            return "t1"
+        return a + 1
+
+    @task
+    def t2(a: typing.Any) -> typing.Any:
+        if type(a) != int:
+            return "t2"
+        return a + 2
+
+    @workflow(pickle_untyped=True)
+    def wf1_with_pickle_untyped(a):
+        a1 = t1(a=a)
+        return t2(a=a1)
+
+    assert wf1_with_pickle_untyped(a=1) == 4
+    assert wf1_with_pickle_untyped(a="1") == "t2"
+
+    @workflow(pickle_untyped=True)
+    def wf2_with_pickle_untyped(a):
+        a1 = t2(a=a)
+        return t1(a=a1)
+
+    assert wf2_with_pickle_untyped(a=1) == 4
+    assert wf2_with_pickle_untyped(a="1") == "t1"
+
+
+def test_pickle_untyped_task_with_specified_input():
+    @task(pickle_untyped=True)
+    def t1(a, b: typing.Any):
+        if type(a) != int:
+            if type(b) != int:
+                return "t1"
+            else:
+                return b
+        elif type(b) != int:
+            return a
+        return a + b
+
+    @workflow(pickle_untyped=True)
+    def wf1_with_pickle_untyped(a: typing.Any, b):
+        r = t1(a=a, b=b)
+        return r
+
+    assert wf1_with_pickle_untyped(a=1, b=2) == 3
+    assert wf1_with_pickle_untyped(a="1", b=2) == 2
+    assert wf1_with_pickle_untyped(a=1, b="2") == 1
+    assert wf1_with_pickle_untyped(a="1", b="2") == "t1"