feat(sdk): support optional artifact inputs (#8623)

* add compiler tests

* support optional artifact inputs

* update executor test

* update existing golden snapshot

* add new compiler test/snapshot

* add release note

* bump kfp-pipeline-spec dependency

sdk/RELEASE.md

@@ -8,6 +8,7 @@
 
 ## Bug fixes and other changes
 * Fully support optional parameter inputs by witing `isOptional` field to IR [\#8612](https://github.com/kubeflow/pipelines/pull/8612)
+* Add support for optional artifact inputs (toward feature parity with KFP SDK v1) [\#8623](https://github.com/kubeflow/pipelines/pull/8623)
 
 ## Documentation updates
 # 2.0.0-beta.9

sdk/python/kfp/compiler/compiler_test.py

@@ -30,6 +30,7 @@ from kfp import dsl
 from kfp.cli import cli
 from kfp.compiler import compiler
 from kfp.components.types import type_utils
+from kfp.dsl import Artifact
 from kfp.dsl import ContainerSpec
 from kfp.dsl import Input
 from kfp.dsl import Model
@@ -2443,6 +2444,213 @@ class TestCompileThenLoadThenUseWithOptionalInputs(unittest.TestCase):
             my_pipeline.pipeline_spec.components['comp-inner-pipeline']
             .input_definitions.parameters['x'].is_optional)
 
+    def test__component__artifact(self):
+
+        @dsl.component
+        def comp(x: Optional[Input[Artifact]] = None):
+            print(x)
+
+        @dsl.pipeline
+        def my_pipeline():
+            comp()
+
+        self.assertTrue(my_pipeline.pipeline_spec.components['comp-comp']
+                        .input_definitions.artifacts['x'].is_optional)
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = os.path.join(tmpdir, 'comp.yaml')
+            compiler.Compiler().compile(comp, path)
+            loaded_comp = components.load_component_from_file(path)
+
+        @dsl.pipeline
+        def my_pipeline():
+            loaded_comp()
+
+        self.assertTrue(my_pipeline.pipeline_spec.components['comp-comp']
+                        .input_definitions.artifacts['x'].is_optional)
+
+    def test__pipeline__artifact(self):
+
+        @dsl.component
+        def comp(x: Optional[Input[Artifact]] = None):
+            print(x)
+
+        @dsl.pipeline
+        def inner_pipeline(x: Optional[Input[Artifact]] = None):
+            comp(x=x)
+
+        @dsl.pipeline
+        def my_pipeline():
+            inner_pipeline()
+
+        self.assertTrue(my_pipeline.pipeline_spec.components['comp-comp']
+                        .input_definitions.artifacts['x'].is_optional)
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = os.path.join(tmpdir, 'comp.yaml')
+            compiler.Compiler().compile(comp, path)
+            loaded_comp = components.load_component_from_file(path)
+
+        @dsl.pipeline
+        def my_pipeline():
+            loaded_comp()
+
+        self.assertTrue(my_pipeline.pipeline_spec.components['comp-comp']
+                        .input_definitions.artifacts['x'].is_optional)
+
+
+class TestCompileOptionalArtifacts(unittest.TestCase):
+
+    def test_python_comp(self):
+
+        @dsl.component
+        def comp(x: Optional[Input[Artifact]] = None):
+            print(x)
+
+        artifact_spec_from_root = comp.pipeline_spec.root.input_definitions.artifacts[
+            'x']
+        self.assertTrue(artifact_spec_from_root.is_optional)
+
+        artifact_spec_from_comp = comp.pipeline_spec.components[
+            'comp-comp'].input_definitions.artifacts['x']
+        self.assertTrue(artifact_spec_from_comp.is_optional)
+
+    def test_python_comp_with_model(self):
+
+        @dsl.component
+        def comp(x: Optional[Input[Model]] = None):
+            print(x)
+
+        artifact_spec_from_root = comp.pipeline_spec.root.input_definitions.artifacts[
+            'x']
+        self.assertTrue(artifact_spec_from_root.is_optional)
+
+        artifact_spec_from_comp = comp.pipeline_spec.components[
+            'comp-comp'].input_definitions.artifacts['x']
+        self.assertTrue(artifact_spec_from_comp.is_optional)
+
+    def test_python_comp_without_optional_type_modifier(self):
+
+        @dsl.component
+        def comp(x: Input[Model] = None):
+            print(x)
+
+        artifact_spec_from_root = comp.pipeline_spec.root.input_definitions.artifacts[
+            'x']
+        self.assertTrue(artifact_spec_from_root.is_optional)
+
+        artifact_spec_from_comp = comp.pipeline_spec.components[
+            'comp-comp'].input_definitions.artifacts['x']
+        self.assertTrue(artifact_spec_from_comp.is_optional)
+
+    def test_container_comp(self):
+
+        @dsl.container_component
+        def comp(x: Optional[Input[Artifact]] = None):
+            return dsl.ContainerSpec(
+                image='alpine',
+                command=[
+                    dsl.IfPresentPlaceholder(
+                        input_name='x',
+                        then=['echo', x.uri],
+                        else_=['echo', 'No artifact provided!'])
+                ])
+
+        artifact_spec_from_root = comp.pipeline_spec.root.input_definitions.artifacts[
+            'x']
+        self.assertTrue(artifact_spec_from_root.is_optional)
+
+        artifact_spec_from_comp = comp.pipeline_spec.components[
+            'comp-comp'].input_definitions.artifacts['x']
+        self.assertTrue(artifact_spec_from_comp.is_optional)
+
+    def test_pipeline(self):
+
+        @dsl.component
+        def comp():
+            print('hello')
+
+        @dsl.pipeline
+        def my_pipeline(x: Optional[Input[Artifact]] = None):
+            comp()
+
+        artifact_spec_from_root = my_pipeline.pipeline_spec.root.input_definitions.artifacts[
+            'x']
+        self.assertTrue(artifact_spec_from_root.is_optional)
+
+    def test_pipeline_without_optional_type_modifier(self):
+
+        @dsl.component
+        def comp():
+            print('hello')
+
+        @dsl.pipeline
+        def my_pipeline(x: Input[Artifact] = None):
+            comp()
+
+        artifact_spec_from_root = my_pipeline.pipeline_spec.root.input_definitions.artifacts[
+            'x']
+        self.assertTrue(artifact_spec_from_root.is_optional)
+
+    def test_pipeline_and_inner_component_together(self):
+
+        @dsl.component
+        def comp(x: Optional[Input[Model]] = None):
+            print(x)
+
+        @dsl.pipeline
+        def my_pipeline(x: Optional[Input[Artifact]] = None):
+            comp()
+
+        artifact_spec_from_root = my_pipeline.pipeline_spec.root.input_definitions.artifacts[
+            'x']
+        self.assertTrue(artifact_spec_from_root.is_optional)
+
+        artifact_spec_from_comp = my_pipeline.pipeline_spec.components[
+            'comp-comp'].input_definitions.artifacts['x']
+        self.assertTrue(artifact_spec_from_comp.is_optional)
+
+    def test_invalid_default_comp(self):
+        with self.assertRaisesRegex(
+                ValueError,
+                'Optional Input artifacts may only have default value None'):
+
+            @dsl.component
+            def comp(x: Optional[Input[Model]] = 1):
+                print(x)
+
+        with self.assertRaisesRegex(
+                ValueError,
+                'Optional Input artifacts may only have default value None'):
+
+            @dsl.component
+            def comp(x: Optional[Input[Model]] = Model(
+                name='', uri='', metadata={})):
+                print(x)
+
+    def test_invalid_default_pipeline(self):
+
+        @dsl.component
+        def comp():
+            print('hello')
+
+        with self.assertRaisesRegex(
+                ValueError,
+                'Optional Input artifacts may only have default value None'):
+
+            @dsl.pipeline
+            def my_pipeline(x: Input[Artifact] = 1):
+                comp()
+
+        with self.assertRaisesRegex(
+                ValueError,
+                'Optional Input artifacts may only have default value None'):
+
+            @dsl.pipeline
+            def my_pipeline(x: Input[Artifact] = Artifact(
+                name='', uri='', metadata={})):
+                comp()
+
 
 if __name__ == '__main__':
     unittest.main()

sdk/python/kfp/compiler/pipeline_spec_builder.py

@@ -337,34 +337,20 @@ def build_component_spec_for_task(
                 f'PipelineTaskFinalStatus can only be used in an exit task. Parameter {input_name} of a non exit task has type PipelineTaskFinalStatus.'
             )
 
-    unprovided_artifact_inputs = []
-    for input_name, input_spec in (task.component_spec.inputs or {}).items():
-        if not type_utils.is_parameter_type(
-                input_spec.type) and input_name not in task.inputs:
-            unprovided_artifact_inputs.append(input_name)
-
     component_spec = _build_component_spec_from_component_spec_structure(
-        task.component_spec, unprovided_artifact_inputs)
+        task.component_spec)
     component_spec.executor_label = utils.sanitize_executor_label(task.name)
     return component_spec
 
 
 def _build_component_spec_from_component_spec_structure(
-    component_spec_struct: structures.ComponentSpec,
+    component_spec_struct: structures.ComponentSpec
-    unprovided_artifact_inputs: Optional[List[str]] = None,
 ) -> pipeline_spec_pb2.ComponentSpec:
     """Builds ComponentSpec proto from ComponentSpec structure."""
-    # TODO: remove unprovided_artifact_inputs from interface and all downstream logic when supporting optional artifact inputs
-    unprovided_artifact_inputs = unprovided_artifact_inputs or []
-
     component_spec = pipeline_spec_pb2.ComponentSpec()
 
     for input_name, input_spec in (component_spec_struct.inputs or {}).items():
 
-        # skip inputs not present, as a workaround to support optional inputs.
-        if input_name in unprovided_artifact_inputs and input_spec.default is None:
-            continue
-
         # Special handling for PipelineTaskFinalStatus first.
         if type_utils.is_task_final_status_type(input_spec.type):
             component_spec.input_definitions.parameters[
@@ -390,6 +376,9 @@ def _build_component_spec_from_component_spec_structure(
                 input_name].artifact_type.CopyFrom(
                     type_utils.bundled_artifact_to_artifact_proto(
                         input_spec.type))
+            if input_spec.optional:
+                component_spec.input_definitions.artifacts[
+                    input_name].is_optional = True
 
     for output_name, output_spec in (component_spec_struct.outputs or
                                      {}).items():

sdk/python/kfp/components/component_factory.py

@@ -184,9 +184,18 @@ def extract_component_interface(
                 )
 
             if parameter.default is not inspect.Parameter.empty:
-                raise ValueError(
+                if passing_style in [
-                    'Default values for Input/Output artifacts are not supported.'
+                        type_annotations.OutputAnnotation,
-                )
+                        type_annotations.OutputPath,
+                ]:
+                    raise ValueError(
+                        'Default values for Output artifacts are not supported.'
+                    )
+                elif parameter.default is not None:
+                    raise ValueError(
+                        f'Optional Input artifacts may only have default value None. Got: {parameter.default}.'
+                    )
+
         elif isinstance(
                 parameter_type,
             (type_annotations.InputPath, type_annotations.OutputPath)):
@@ -229,7 +238,8 @@ def extract_component_interface(
                 type_struct, parameter_type.schema_version
             ) if type_annotations.is_artifact_class(
                 parameter_type) else type_struct
-            default = None if parameter.default == inspect.Parameter.empty else parameter.default
+            default = None if parameter.default == inspect.Parameter.empty or type_annotations.is_artifact_class(
+                parameter_type) else parameter.default
             optional = parameter.default is not inspect.Parameter.empty or type_utils.is_task_final_status_type(
                 type_struct)
             input_spec = structures.InputSpec(

sdk/python/kfp/components/executor_test.py

@@ -849,6 +849,21 @@ class ExecutorTest(unittest.TestCase):
                 },
             })
 
+    def test_function_with_optional_input_artifact(self):
+        executor_input = """\
+        {
+          "inputs": {},
+          "outputs": {
+            "outputFile": "%(test_dir)s/output_metadata.json"
+          }
+        }
+        """
+
+        def test_func(a: Optional[Input[Artifact]] = None):
+            self.assertIsNone(a)
+
+        self.execute(test_func, executor_input)
+
     def test_function_with_pipeline_task_final_status(self):
         executor_input = """\
     {

sdk/python/kfp/components/structures.py

@@ -88,9 +88,13 @@ class InputSpec:
             type_ = ir_component_inputs_dict['artifactType']['schemaTitle']
             schema_version = ir_component_inputs_dict['artifactType'][
                 'schemaVersion']
+            # TODO: would be better to extract these fields from the proto
+            # message, as False default would be preserved
+            optional = ir_component_inputs_dict.get('isOptional', False)
             return InputSpec(
                 type=type_utils.create_bundled_artifact_type(
-                    type_, schema_version))
+                    type_, schema_version),
+                optional=optional)
 
     def __eq__(self, other: Any) -> bool:
         """Equality comparison for InputSpec. Robust to different type

sdk/python/requirements.in

@@ -16,7 +16,7 @@ google-cloud-storage>=2.2.1,<3
 # NOTE: Maintainers, please do not require google-auth>=2.x.x
 # Until this issue is closed
 # https://github.com/googleapis/google-cloud-python/issues/10566
-kfp-pipeline-spec>=0.1.16,<0.2.0
+kfp-pipeline-spec>=0.1.17,<0.2.0
 # Update the upper version whenever a new major version of the
 # kfp-server-api package is released.
 # Update the lower version when kfp sdk depends on new apis/fields in

sdk/python/requirements.txt

@@ -1,6 +1,6 @@
 #
-# This file is autogenerated by pip-compile with python 3.7
+# This file is autogenerated by pip-compile with Python 3.7
-# To update, run:
+# by the following command:
 #
 #    pip-compile --no-emit-index-url requirements.in
 #
@@ -59,7 +59,7 @@ importlib-metadata==4.12.0
     #   jsonschema
 jsonschema==3.2.0
     # via -r requirements.in
-kfp-pipeline-spec==0.1.16
+kfp-pipeline-spec==0.1.17
     # via -r requirements.in
 kfp-server-api==2.0.0a4
     # via -r requirements.in

sdk/python/test_data/pipelines/components_with_optional_artifacts.py

@@ -0,0 +1,66 @@
+# Copyright 2022 The Kubeflow Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from typing import Optional
+
+from kfp import compiler
+from kfp import dsl
+from kfp.dsl import Artifact
+from kfp.dsl import Dataset
+from kfp.dsl import Input
+
+
+@dsl.component
+def python_artifact_printer(artifact: Optional[Input[Artifact]] = None):
+    if artifact is not None:
+        print(artifact.name)
+        print(artifact.uri)
+        print(artifact.metadata)
+    else:
+        print('No artifact provided!')
+
+
+@dsl.container_component
+def custom_artifact_printer(artifact: Optional[Input[Artifact]] = None):
+    return dsl.ContainerSpec(
+        image='alpine',
+        command=[
+            dsl.IfPresentPlaceholder(
+                input_name='artifact',
+                then=['echo', artifact.uri],
+                else_=['echo', 'No artifact provided!'])
+        ])
+
+
+@dsl.pipeline
+def inner_pipeline(dataset: Optional[Input[Dataset]] = None):
+    python_artifact_printer(artifact=dataset)
+
+
+@dsl.pipeline(name='optional-artifact-pipeline')
+def pipeline(dataset1: Optional[Input[Dataset]] = None):
+
+    custom_artifact_printer(artifact=dataset1)
+    custom_artifact_printer()
+
+    dataset2 = dsl.importer(
+        artifact_uri='gs://ml-pipeline-playground/shakespeare1.txt',
+        artifact_class=Dataset,
+    )
+    inner_pipeline(dataset=dataset2.output)
+    inner_pipeline()
+
+
+if __name__ == '__main__':
+    compiler.Compiler().compile(
+        pipeline_func=pipeline, package_path=__file__.replace('.py', '.yaml'))

sdk/python/test_data/pipelines/components_with_optional_artifacts.yaml

@@ -0,0 +1,240 @@
+# PIPELINE DEFINITION
+# Name: optional-artifact-pipeline
+# Inputs:
+#    dataset1: system.Dataset
+components:
+  comp-custom-artifact-printer:
+    executorLabel: exec-custom-artifact-printer
+    inputDefinitions:
+      artifacts:
+        artifact:
+          artifactType:
+            schemaTitle: system.Artifact
+            schemaVersion: 0.0.1
+          isOptional: true
+  comp-custom-artifact-printer-2:
+    executorLabel: exec-custom-artifact-printer-2
+    inputDefinitions:
+      artifacts:
+        artifact:
+          artifactType:
+            schemaTitle: system.Artifact
+            schemaVersion: 0.0.1
+          isOptional: true
+  comp-importer:
+    executorLabel: exec-importer
+    inputDefinitions:
+      parameters:
+        uri:
+          parameterType: STRING
+    outputDefinitions:
+      artifacts:
+        artifact:
+          artifactType:
+            schemaTitle: system.Dataset
+            schemaVersion: 0.0.1
+  comp-inner-pipeline:
+    dag:
+      tasks:
+        python-artifact-printer:
+          cachingOptions:
+            enableCache: true
+          componentRef:
+            name: comp-python-artifact-printer
+          inputs:
+            artifacts:
+              artifact:
+                componentInputArtifact: dataset
+          taskInfo:
+            name: python-artifact-printer
+    inputDefinitions:
+      artifacts:
+        dataset:
+          artifactType:
+            schemaTitle: system.Dataset
+            schemaVersion: 0.0.1
+          isOptional: true
+  comp-inner-pipeline-2:
+    dag:
+      tasks:
+        python-artifact-printer:
+          cachingOptions:
+            enableCache: true
+          componentRef:
+            name: comp-python-artifact-printer-2
+          inputs:
+            artifacts:
+              artifact:
+                componentInputArtifact: dataset
+          taskInfo:
+            name: python-artifact-printer
+    inputDefinitions:
+      artifacts:
+        dataset:
+          artifactType:
+            schemaTitle: system.Dataset
+            schemaVersion: 0.0.1
+          isOptional: true
+  comp-python-artifact-printer:
+    executorLabel: exec-python-artifact-printer
+    inputDefinitions:
+      artifacts:
+        artifact:
+          artifactType:
+            schemaTitle: system.Artifact
+            schemaVersion: 0.0.1
+          isOptional: true
+  comp-python-artifact-printer-2:
+    executorLabel: exec-python-artifact-printer-2
+    inputDefinitions:
+      artifacts:
+        artifact:
+          artifactType:
+            schemaTitle: system.Artifact
+            schemaVersion: 0.0.1
+          isOptional: true
+deploymentSpec:
+  executors:
+    exec-custom-artifact-printer:
+      container:
+        command:
+        - '{"IfPresent": {"InputName": "artifact", "Then": ["echo", "{{$.inputs.artifacts[''artifact''].uri}}"],
+          "Else": ["echo", "No artifact provided!"]}}'
+        image: alpine
+    exec-custom-artifact-printer-2:
+      container:
+        command:
+        - '{"IfPresent": {"InputName": "artifact", "Then": ["echo", "{{$.inputs.artifacts[''artifact''].uri}}"],
+          "Else": ["echo", "No artifact provided!"]}}'
+        image: alpine
+    exec-importer:
+      importer:
+        artifactUri:
+          constant: gs://ml-pipeline-playground/shakespeare1.txt
+        typeSchema:
+          schemaTitle: system.Dataset
+          schemaVersion: 0.0.1
+    exec-python-artifact-printer:
+      container:
+        args:
+        - --executor_input
+        - '{{$}}'
+        - --function_to_execute
+        - python_artifact_printer
+        command:
+        - sh
+        - -c
+        - "\nif ! [ -x \"$(command -v pip)\" ]; then\n    python3 -m ensurepip ||\
+          \ python3 -m ensurepip --user || apt-get install python3-pip\nfi\n\nPIP_DISABLE_PIP_VERSION_CHECK=1\
+          \ python3 -m pip install --quiet     --no-warn-script-location 'kfp==2.0.0-beta.9'\
+          \ && \"$0\" \"$@\"\n"
+        - sh
+        - -ec
+        - 'program_path=$(mktemp -d)
+
+          printf "%s" "$0" > "$program_path/ephemeral_component.py"
+
+          python3 -m kfp.components.executor_main                         --component_module_path                         "$program_path/ephemeral_component.py"                         "$@"
+
+          '
+        - "\nimport kfp\nfrom kfp import dsl\nfrom kfp.dsl import *\nfrom typing import\
+          \ *\n\ndef python_artifact_printer(artifact: Optional[Input[Artifact]] =\
+          \ None):\n    if artifact is not None:\n        print(artifact.name)\n \
+          \       print(artifact.uri)\n        print(artifact.metadata)\n    else:\n\
+          \        print('No artifact provided!')\n\n"
+        image: python:3.7
+    exec-python-artifact-printer-2:
+      container:
+        args:
+        - --executor_input
+        - '{{$}}'
+        - --function_to_execute
+        - python_artifact_printer
+        command:
+        - sh
+        - -c
+        - "\nif ! [ -x \"$(command -v pip)\" ]; then\n    python3 -m ensurepip ||\
+          \ python3 -m ensurepip --user || apt-get install python3-pip\nfi\n\nPIP_DISABLE_PIP_VERSION_CHECK=1\
+          \ python3 -m pip install --quiet     --no-warn-script-location 'kfp==2.0.0-beta.9'\
+          \ && \"$0\" \"$@\"\n"
+        - sh
+        - -ec
+        - 'program_path=$(mktemp -d)
+
+          printf "%s" "$0" > "$program_path/ephemeral_component.py"
+
+          python3 -m kfp.components.executor_main                         --component_module_path                         "$program_path/ephemeral_component.py"                         "$@"
+
+          '
+        - "\nimport kfp\nfrom kfp import dsl\nfrom kfp.dsl import *\nfrom typing import\
+          \ *\n\ndef python_artifact_printer(artifact: Optional[Input[Artifact]] =\
+          \ None):\n    if artifact is not None:\n        print(artifact.name)\n \
+          \       print(artifact.uri)\n        print(artifact.metadata)\n    else:\n\
+          \        print('No artifact provided!')\n\n"
+        image: python:3.7
+pipelineInfo:
+  name: optional-artifact-pipeline
+root:
+  dag:
+    tasks:
+      custom-artifact-printer:
+        cachingOptions:
+          enableCache: true
+        componentRef:
+          name: comp-custom-artifact-printer
+        inputs:
+          artifacts:
+            artifact:
+              componentInputArtifact: dataset1
+        taskInfo:
+          name: custom-artifact-printer
+      custom-artifact-printer-2:
+        cachingOptions:
+          enableCache: true
+        componentRef:
+          name: comp-custom-artifact-printer-2
+        taskInfo:
+          name: custom-artifact-printer-2
+      importer:
+        cachingOptions:
+          enableCache: true
+        componentRef:
+          name: comp-importer
+        inputs:
+          parameters:
+            uri:
+              runtimeValue:
+                constant: gs://ml-pipeline-playground/shakespeare1.txt
+        taskInfo:
+          name: importer
+      inner-pipeline:
+        cachingOptions:
+          enableCache: true
+        componentRef:
+          name: comp-inner-pipeline
+        dependentTasks:
+        - importer
+        inputs:
+          artifacts:
+            dataset:
+              taskOutputArtifact:
+                outputArtifactKey: artifact
+                producerTask: importer
+        taskInfo:
+          name: inner-pipeline
+      inner-pipeline-2:
+        cachingOptions:
+          enableCache: true
+        componentRef:
+          name: comp-inner-pipeline-2
+        taskInfo:
+          name: inner-pipeline-2
+  inputDefinitions:
+    artifacts:
+      dataset1:
+        artifactType:
+          schemaTitle: system.Dataset
+          schemaVersion: 0.0.1
+        isOptional: true
+schemaVersion: 2.1.0
+sdkVersion: kfp-2.0.0-beta.9

sdk/python/test_data/pipelines/xgboost_sample_pipeline.yaml

@@ -133,6 +133,11 @@ components:
     executorLabel: exec-xgboost-train
     inputDefinitions:
       artifacts:
+        starting_model:
+          artifactType:
+            schemaTitle: system.Artifact
+            schemaVersion: 0.0.1
+          isOptional: true
         training_data:
           artifactType:
             schemaTitle: system.Artifact
@@ -183,6 +188,11 @@ components:
     executorLabel: exec-xgboost-train-2
     inputDefinitions:
       artifacts:
+        starting_model:
+          artifactType:
+            schemaTitle: system.Artifact
+            schemaVersion: 0.0.1
+          isOptional: true
         training_data:
           artifactType:
             schemaTitle: system.Artifact
@@ -914,4 +924,4 @@ root:
         taskInfo:
           name: xgboost-train-2
 schemaVersion: 2.1.0
-sdkVersion: kfp-2.0.0-beta.8
+sdkVersion: kfp-2.0.0-beta.9

sdk/python/test_data/test_data_config.yaml

@@ -141,6 +141,9 @@ pipelines:
     - module: pipeline_with_dynamic_importer_metadata
       name: my_pipeline
       execute: false
+    - module: components_with_optional_artifacts
+      name: pipeline
+      execute: false
 components:
   test_data_dir: sdk/python/test_data/components
   read: true