Kubeflow Pipelines SDK for Tekton

The Kubeflow Pipelines SDK allows data scientists to define end-to-end machine learning and data pipelines. The output of the Kubeflow Pipelines SDK compiler is YAML for Argo.

The kfp-tekton SDK is extending the Compiler and the Client of the Kubeflow Pipelines SDK to generate Tekton YAML and to subsequently upload and run the pipeline with the Kubeflow Pipelines engine backed by Tekton.

Table of Contents

• SDK Packages Overview
• Project Prerequisites
• Installation
• Compiling a Kubeflow Pipelines DSL Script
• Big data passing workspace configuration
• Running the Compiled Pipeline on a Tekton Cluster
• List of Available Features
• List of Helper Functions for Python Kubernetes Client
• Tested Pipelines
• Troubleshooting

SDK Packages Overview

The kfp-tekton SDK is an extension to the Kubeflow Pipelines SDK adding the TektonCompiler and the TektonClient:

• kfp_tekton.compiler includes classes and methods for compiling pipeline Python DSL into a Tekton PipelineRun YAML spec. The methods in this package include, but are not limited to, the following:

  • kfp_tekton.compiler.TektonCompiler.compile compiles your Python DSL code into a single static configuration (in YAML format) that the Kubeflow Pipelines service can process. The Kubeflow Pipelines service converts the static configuration into a set of Kubernetes resources for execution.

• kfp_tekton.TektonClient contains the Python client libraries for the Kubeflow Pipelines API. Methods in this package include, but are not limited to, the following:

  • kfp_tekton.TektonClient.upload_pipeline uploads a local file to create a new pipeline in Kubeflow Pipelines.
  • kfp_tekton.TektonClient.create_experiment creates a pipeline experiment and returns an experiment object.
  • kfp_tekton.TektonClient.run_pipeline runs a pipeline and returns a run object.
  • kfp_tekton.TektonClient.create_run_from_pipeline_func compiles a pipeline function and submits it for execution on Kubeflow Pipelines.
  • kfp_tekton.TektonClient.create_run_from_pipeline_package runs a local pipeline package on Kubeflow Pipelines.

Project Prerequisites

• Python: 3.7 or later
• Tekton: v0.36.0 or later
• Tekton CLI: 0.23.1
• Kubeflow Pipelines: KFP with Tekton backend

Follow the instructions for installing project prerequisites and take note of some important caveats.

Installation

You can install the latest release of the kfp-tekton compiler from PyPi. We recommend to create a Python virtual environment first:

python3 -m venv .venv
source .venv/bin/activate

pip install kfp-tekton

Alternatively you can install the latest version of the kfp-tekton compiler from the source by cloning the repository https://github.com/kubeflow/kfp-tekton:

1. Clone the kfp-tekton repo:

   git clone https://github.com/kubeflow/kfp-tekton.git
   cd kfp-tekton
   

2. Setup Python environment with Conda or a Python virtual environment:

   python3 -m venv .venv
   source .venv/bin/activate
   

3. Build the compiler:

   pip install -e sdk/python
   

4. Run the compiler tests (optional):

   pip install pytest
   make test
   

Compiling a Kubeflow Pipelines DSL Script

The kfp-tekton Python package comes with the dsl-compile-tekton command line executable, which should be available in your terminal shell environment after installing the kfp-tekton Python package.

If you cloned the kfp-tekton project, you can find example pipelines in the samples folder or under sdk/python/tests/compiler/testdata folder.

dsl-compile-tekton \
    --py sdk/python/tests/compiler/testdata/parallel_join.py \
    --output pipeline.yaml

Note: If the KFP DSL script contains a __main__ method calling the kfp_tekton.compiler.TektonCompiler.compile() function:

if __name__ == "__main__":
    from kfp_tekton.compiler import TektonCompiler
    TektonCompiler().compile(pipeline_func, "pipeline.yaml")

... then the pipeline can be compiled by running the DSL script with python3 executable from a command line shell, producing a Tekton YAML file pipeline.yaml in the same directory:

python3 pipeline.py

Big data passing workspace configuration

When big data files are defined in KFP. Tekton will create a workspace to share these big data files among tasks that run in the same pipeline. By default, the workspace is a Read Write Many PVC with 2Gi storage using the kfp-csi-s3 storage class to push artifacts to S3. But you can change these configuration using the environment variables below:

export DEFAULT_ACCESSMODES=ReadWriteMany
export DEFAULT_STORAGE_SIZE=2Gi
export DEFAULT_STORAGE_CLASS=kfp-csi-s3

To pass big data using cloud provider volumes, it's recommended to use the volume_based_data_passing_method for both Tekton and Argo runtime.

Running the Compiled Pipeline on a Tekton Cluster

After compiling the sdk/python/tests/compiler/testdata/parallel_join.py DSL script in the step above, we need to deploy the generated Tekton YAML to Kubeflow Pipeline engine.

You can run the pipeline directly using a pre-compiled file and KFP-Tekton SDK. For more details, please look at the KFP-Tekton user guide SDK documentation

experiment = kfp_tekton.TektonClient.create_experiment(name=EXPERIMENT_NAME, namespace=KUBEFLOW_PROFILE_NAME)
run = client.run_pipeline(experiment.id, 'parallal-join-pipeline', 'pipeline.yaml')

You can also deploy directly on Tekton cluster with kubectl. The Tekton server will automatically start a pipeline run. We can then follow the logs using the tkn CLI.

kubectl apply -f pipeline.yaml

tkn pipelinerun logs --last --follow

Once the Tekton Pipeline is running, the logs should start streaming:

Waiting for logs to be available...

[gcs-download : main] With which he yoketh your rebellious necks Razeth your cities and subverts your towns And in a moment makes them desolate

[gcs-download-2 : main] I find thou art no less than fame hath bruited And more than may be gatherd by thy shape Let my presumption not provoke thy wrath

[echo : main] Text 1: With which he yoketh your rebellious necks Razeth your cities and subverts your towns And in a moment makes them desolate
[echo : main]
[echo : main] Text 2: I find thou art no less than fame hath bruited And more than may be gatherd by thy shape Let my presumption not provoke thy wrath
[echo : main]

List of Available Features

To understand how each feature is implemented and its current status, please visit the FEATURES doc.

List of Helper Functions for Python Kubernetes Client

KFP Tekton provides a list of common Kubernetes client helper functions to simplify the process of creating certain Kubernetes resources. please visit the K8S_CLIENT_HELPER doc for more details.

Tested Pipelines

We are testing the compiler on more than 80 pipelines found in the Kubeflow Pipelines repository, specifically the pipelines in KFP compiler testdata folder, the KFP core samples and the samples contributed by third parties.

A report card of Kubeflow Pipelines samples that are currently supported by the kfp-tekton compiler can be found here. If you work on a PR that enables another of the missing features please ensure that your code changes are improving the number of successfully compiled KFP pipeline samples.

Troubleshooting

• When you encounter ServiceAccount related permission issues, refer to the "Service Account and RBAC" doc

• If you run into the error bad interpreter: No such file or director when trying to use Python's venv, remove the current virtual environment in the .venv directory and create a new one using virtualenv .venv