Continuous Integration for Machine Learning Pipelines on GitHub

Question

Pulumi · Accepted Answer

Continuous Integration (CI) is a development practice where developers integrate code into a shared repository frequently, preferably several times a day. Each integration can then be verified by an automated build and automated testing. Although not specific to machine learning (ML) workflows, CI can certainly be applied to them.

In the context of a machine learning pipeline, Continuous Integration might involve the following steps:

1. **Automated Testing**: Upon each commit, machine learning code is tested for correctness. This can include unit tests for functions, integration tests for machine learning pipelines, and data validation tests to ensure that the data used for training meets certain criteria.

2. **Training Models**: After the tests pass, the ML model is trained with the current dataset. This can be done on every commit, daily, or with some other frequency.

3. **Evaluation**: Once the model is trained, it's important to evaluate its performance to see if it meets the required performance criteria. This is usually done through a set of evaluation metrics specific to the problem that the model is trying to solve.

4. **Versioning**: Keep track of the code, data, and model versions so that you can roll back to a previous model if necessary.

To implement Continuous Integration for ML pipelines on GitHub, you'll typically use GitHub Actions – GitHub's own automation tool that can run workflows based on GitHub events like push, pull requests, etc.

Below is a program written in Python using Pulumi with GitHub provider. This program will set up a basic Continuous Integration workflow using GitHub Actions for a machine learning project. This is a high-level overview; details such as the specific machine learning tests and model training steps will be unique to your project.

```python
import pulumi
import pulumi_github as github

# Configuration variables for the GitHub repository
repo_name = "ml-project"
owner = "your-github-username"

# Instantiate a GitHub repository
repo = github.Repository(repo_name,
    name=repo_name,
    description="Machine Learning project repository",
    visibility="public"  # can be "private" for private repositories
)

# Define the content of the GitHub Actions workflow
ci_workflow_content = """
name: ML CI Pipeline

on: [push]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Set up Python
      uses: actions/setup-python@v2
      with:
        python-version: '3.8'
    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip
        pip install -r requirements.txt
    - name: Run tests
      run: |
        pytest tests/
    # Add more steps for training and evaluating machine learning model here
"""

# Define a GitHub Actions Workflow (.github/workflows/ml-ci.yml) inside the repository
ci_workflow = github.Workflow("ml-ci-workflow",
    repository=repo.name,
    content=pulumi.Output.secret(ci_workflow_content)
)

# Export the URL of the repository
pulumi.export('repository_url', repo.html_url)
```

This Pulumi program will:

- Create a new GitHub repository named `ml-project` or use an existing one if it's already there.
- Set up a new GitHub Actions workflow inside the `.github/workflows/` directory of the repository. The workflow named `ml-ci.yml` is defined by the `ci_workflow_content` variable, which specifies the steps that run when code is pushed to the repository.
- The workflow in this example sets up a Python environment, installs dependencies, and runs tests using `pytest`. To adapt this workflow to a specific ML project, you would add steps to train and evaluate your model.

Each of these steps corresponds to the Github Actions CI pipeline which would automatically trigger every time you push the code changes to your repository.

To make this work for a real machine learning project, you would need to:

- Customize the `ci_workflow_content` with steps that are appropriate for your ML pipeline, such as installing additional dependencies, running data validation, training models, evaluating models, and possibly deploying the trained model.
- Store secret credentials and sensitive data using [GitHub Secrets](https://docs.github.com/en/actions/security-guides/encrypted-secrets) and refer to them in your Github Actions workflow if needed.

To use this program:

1. Copy the program to a Python file, for example `main.py`.
2. Ensure you have Pulumi installed and configured for your GitHub account.
3. Run `pulumi up` to preview and deploy these changes to your GitHub repository.

Remember, for a real-world machine learning project, you will have a much more complex workflow that includes data validation, complex machine learning tests, model training and evaluation, and perhaps deployment steps.