enable parameterization of container images

This change allows component base images to be parameterized using runtime pipeline parameters. The container images can be specified within an @pipeline decorated function, and takes precedence over the @component(base_image=..) argument.

This change also adds logic to resolve these runtime parameters in the argo driver logic. It also includes resolution steps for resolving the accelerator type which functions the same way but was missing the resolution logic. The resolution logic is a generic workaround solution for any run time pod spec input parameters that cannot be resolved because they cannot be added dynamically in the argo pod spec container template.

Signed-off-by: Humair Khan <[email protected]>

backend/src/v2/driver/driver.go

@@ -11,6 +11,7 @@
 // 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.
+
 package driver
 
 import (
@@ -448,19 +449,28 @@ func initPodSpecPatch(
 	accelerator := container.GetResources().GetAccelerator()
 	if accelerator != nil {
 		if accelerator.GetType() != "" && accelerator.GetCount() > 0 {
-			q, err := k8sres.ParseQuantity(fmt.Sprintf("%v", accelerator.GetCount()))
-			if err != nil {
-				return nil, fmt.Errorf("failed to init podSpecPatch: %w", err)
+			acceleratorType, err1 := resolvePodSpecRuntimeParameter(accelerator.GetType(), executorInput)
+			if err1 != nil {
+				return nil, err1
 			}
-			res.Limits[k8score.ResourceName(accelerator.GetType())] = q
+			q, err1 := k8sres.ParseQuantity(fmt.Sprintf("%v", accelerator.GetCount()))
+			if err1 != nil {
+				return nil, fmt.Errorf("failed to init podSpecPatch: %w", err1)
+			}
+			res.Limits[k8score.ResourceName(acceleratorType)] = q
 		}
 	}
+
+	containerImage, err := resolvePodSpecRuntimeParameter(container.Image, executorInput)
+	if err != nil {
+		return nil, err
+	}
 	podSpec := &k8score.PodSpec{
 		Containers: []k8score.Container{{
 			Name:      "main", // argo task user container is always called "main"
 			Command:   launcherCmd,
 			Args:      userCmdArgs,
-			Image:     container.Image,
+			Image:     containerImage,
 			Resources: res,
 			Env:       userEnvVar,
 		}},

backend/src/v2/driver/util.go

@@ -0,0 +1,78 @@
+// Copyright 2021-2024 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
+//
+//	https://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.
+
+package driver
+
+import (
+	"fmt"
+	"github.com/kubeflow/pipelines/api/v2alpha1/go/pipelinespec"
+	"regexp"
+)
+
+// InputPipelineChannelPattern define a regex pattern to match the content within single quotes
+// example input channel looks like "{{$.inputs.parameters['pipelinechannel--val']}}"
+const InputPipelineChannelPattern = `\$.inputs.parameters\['(.+?)'\]`
+
+func isInputParameterChannel(inputChannel string) bool {
+	re := regexp.MustCompile(InputPipelineChannelPattern)
+	match := re.FindStringSubmatch(inputChannel)
+	if len(match) == 2 {
+		return true
+	} else {
+		// if len(match) > 2, then this is still incorrect because
+		// inputChannel should contain only one parameter channel input
+		return false
+	}
+}
+
+// extractInputParameterFromChannel takes an inputChannel that adheres to
+// InputPipelineChannelPattern and extracts the channel parameter name.
+// For example given an input channel of the form "{{$.inputs.parameters['pipelinechannel--val']}}"
+// the channel parameter name "pipelinechannel--val" is returned.
+func extractInputParameterFromChannel(inputChannel string) (string, error) {
+	re := regexp.MustCompile(InputPipelineChannelPattern)
+	match := re.FindStringSubmatch(inputChannel)
+	if len(match) > 1 {
+		extractedValue := match[1]
+		return extractedValue, nil
+	} else {
+		return "", fmt.Errorf("failed to extract input parameter from channel: %s", inputChannel)
+	}
+}
+
+// resolvePodSpecRuntimeParameter resolves runtime value that is intended to be
+// utilized within the Pod Spec. parameterValue takes the form of:
+// "{{$.inputs.parameters['pipelinechannel--someParameterName']}}"
+//
+// parameterValue is a runtime parameter value that has been resolved and included within
+// the executor input. Since the pod spec patch cannot dynamically update the underlying
+// container template's inputs in an Argo Workflow, this is a workaround for resolving
+// such parameters.
+//
+// If parameter value is not a parameter channel, then a constant value is assumed and
+// returned as is.
+func resolvePodSpecRuntimeParameter(parameterValue string, executorInput *pipelinespec.ExecutorInput) (string, error) {
+	if isInputParameterChannel(parameterValue) {
+		inputImage, err1 := extractInputParameterFromChannel(parameterValue)
+		if err1 != nil {
+			return "", err1
+		}
+		if val, ok := executorInput.Inputs.ParameterValues[inputImage]; ok {
+			return val.GetStringValue(), nil
+		} else {
+			return "", fmt.Errorf("executorInput did not contain container Image input parameter")
+		}
+	}
+	return parameterValue, nil
+}

sdk/python/kfp/compiler/compiler_test.py

@@ -909,6 +909,70 @@ def my_pipeline() -> NamedTuple('Outputs', [
             ]):
                 task = print_and_return(text='Hello')
 
+    def test_pipeline_with_parameterized_container_image(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+
+            @dsl.component(base_image='docker.io/python:3.9.17')
+            def empty_component():
+                pass
+
+            @dsl.pipeline()
+            def simple_pipeline(img: str):
+                task = empty_component()
+                # overwrite base_image="docker.io/python:3.9.17"
+                task.set_container_image(img)
+
+            output_yaml = os.path.join(tmpdir, 'result.yaml')
+            compiler.Compiler().compile(
+                pipeline_func=simple_pipeline,
+                package_path=output_yaml,
+                pipeline_parameters={'img': 'someimage'})
+            self.assertTrue(os.path.exists(output_yaml))
+
+            with open(output_yaml, 'r') as f:
+                pipeline_spec = yaml.safe_load(f)
+                container = pipeline_spec['deploymentSpec']['executors'][
+                    'exec-empty-component']['container']
+                self.assertEqual(
+                    container['image'],
+                    "{{$.inputs.parameters['pipelinechannel--img']}}")
+                # A parameter value should result in 2 input parameters
+                # One for storing pipeline channel template to be resolved during runtime.
+                # Two for holding the key to the resolved input.
+                input_parameters = pipeline_spec['root']['dag']['tasks'][
+                    'empty-component']['inputs']['parameters']
+                self.assertTrue('base_image' in input_parameters)
+                self.assertTrue('pipelinechannel--img' in input_parameters)
+
+    def test_pipeline_with_constant_container_image(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+
+            @dsl.component(base_image='docker.io/python:3.9.17')
+            def empty_component():
+                pass
+
+            @dsl.pipeline()
+            def simple_pipeline():
+                task = empty_component()
+                # overwrite base_image="docker.io/python:3.9.17"
+                task.set_container_image('constant-value')
+
+            output_yaml = os.path.join(tmpdir, 'result.yaml')
+            compiler.Compiler().compile(
+                pipeline_func=simple_pipeline, package_path=output_yaml)
+
+            self.assertTrue(os.path.exists(output_yaml))
+
+            with open(output_yaml, 'r') as f:
+                pipeline_spec = yaml.safe_load(f)
+                container = pipeline_spec['deploymentSpec']['executors'][
+                    'exec-empty-component']['container']
+                self.assertEqual(container['image'], 'constant-value')
+                # A constant value should yield no parameters
+                dag_task = pipeline_spec['root']['dag']['tasks'][
+                    'empty-component']
+                self.assertTrue('inputs' not in dag_task)
+
 
 class TestCompilePipelineCaching(unittest.TestCase):
 

sdk/python/kfp/compiler/pipeline_spec_builder.py

@@ -135,6 +135,11 @@ def build_task_spec_for_task(
             if val and pipeline_channel.extract_pipeline_channels_from_any(val):
                 task.inputs[key] = val
 
+    if task.container_spec and task.container_spec.image:
+        val = task.container_spec.image
+        if val and pipeline_channel.extract_pipeline_channels_from_any(val):
+            task.inputs['base_image'] = val
+
     for input_name, input_value in task.inputs.items():
         # Since LoopParameterArgument and LoopArtifactArgument and LoopArgumentVariable are narrower
         # types than PipelineParameterChannel, start with them.
@@ -634,7 +639,7 @@ def convert_to_placeholder(input_value: str) -> str:
 
     container_spec = (
         pipeline_spec_pb2.PipelineDeploymentConfig.PipelineContainerSpec(
-            image=task.container_spec.image,
+            image=convert_to_placeholder(task.container_spec.image),
             command=task.container_spec.command,
             args=task.container_spec.args,
             env=[

sdk/python/kfp/dsl/pipeline_task.py

@@ -631,6 +631,17 @@ def set_env_variable(self, name: str, value: str) -> 'PipelineTask':
             self.container_spec.env = {name: value}
         return self
 
+    @block_if_final()
+    def set_container_image(
+            self,
+            name: Union[str,
+                        pipeline_channel.PipelineChannel]) -> 'PipelineTask':
+        self._ensure_container_spec_exists()
+        if isinstance(name, pipeline_channel.PipelineChannel):
+            name = str(name)
+        self.container_spec.image = name
+        return self
+
     @block_if_final()
     def after(self, *tasks) -> 'PipelineTask':
         """Specifies an explicit dependency on other tasks by requiring this