README.md

Dagster Data Workflows Project

This repository contains various data processing workflows implemented using Dagster, designed to run in a Kubernetes environment.

Project Structure

my_dagster_project/
├── Dockerfile
├── pyproject.toml
└── my_dagster_project/
    ├── __init__.py
    ├── assets/
    │   ├── __init__.py
    │   ├── pandas_workflow.py
    │   ├── polars_workflow.py
    │   ├── duckdb_workflow.py
    │   ├── postgres_workflow.py
    │   └── sales_workflow.py
    └── resources/
        ├── __init__.py
        └── database.py

Current Workflows

1. Pandas Workflow: Stock market data analysis
2. Polars Workflow: Weather data analysis
3. DuckDB Workflow: Analytics using DuckDB
4. Postgres Workflow: Database operations
5. Sales Workflow: Synthetic data analysis

Adding New Workflows

1. Create New Asset File

# my_dagster_project/assets/new_workflow.py

from dagster import asset, Output, MetadataValue

@asset
def my_new_asset():
    """
    Description of what this asset does
    """
    # Your asset logic here
    return Output(
        result,
        metadata={
            "rows": len(result),
            "preview": MetadataValue.md(result.head().to_markdown())
        }
    )

2. Adding Resources (if needed)

# my_dagster_project/resources/new_resource.py

from dagster import resource

@resource(config_schema={"param": str})
def my_new_resource(context):
    return MyResourceClass(context.resource_config["param"])

3. Register Resource (if added)

Update my_dagster_project/__init__.py:

from dagster import Definitions
from .resources.new_resource import my_new_resource

defs = Definitions(
    assets=[],  # Assets are auto-discovered
    resources={
        "my_new_resource": my_new_resource,
        # ... other resources
    }
)

Docker Image Generation

The CI/CD pipeline automatically builds and pushes Docker images based on git actions:

1. Branch Builds:

   • Format: your-username/my-dagster-project:branch-name
   • Example: your-username/my-dagster-project:feature-new-workflow

2. Pull Request Builds:

   • Format: your-username/my-dagster-project:pr-{number}
   • Example: your-username/my-dagster-project:pr-123

3. Release Tags:

   • Format: your-username/my-dagster-project:{version}
   • Example: your-username/my-dagster-project:1.0.0

4. Main Branch:

   • Tag: your-username/my-dagster-project:latest

5. Commit SHA:

   • Format: your-username/my-dagster-project:sha-{hash}
   • Example: your-username/my-dagster-project:sha-a1b2c3d

Deploying to Kubernetes

1. Create Deployment File

# kubernetes/my-workflow-deployment.yaml
apiVersion: dagster.io/v1alpha1
kind: UserDeployment
metadata:
  name: my-new-workflow
spec:
  deployment:
    image:
      repository: your-username/my-dagster-project
      tag: latest  # or specific version
    dagsterApiGrpcArgs:
      - "--module-name"
      - "my_dagster_project"

2. Deploy to Kubernetes

# Deploy new version
kubectl apply -f kubernetes/my-workflow-deployment.yaml

# Check deployment status
kubectl get userdeployments

3. Update Existing Deployment

# Update image version
kubectl patch userdeployment my-new-workflow --type=json \
  -p='[{"op": "replace", "path": "/spec/deployment/image/tag", "value": "1.0.1"}]'

Development Guidelines

1. Code Style

• Use Black for code formatting
• Add type hints where possible
• Include docstrings for all assets and resources

2. Testing

# Run tests
pytest tests/

# Format code
black .
isort .

3. Version Control

• Create feature branches from main
• Use conventional commits:
  • feat: New feature
  • fix: Bug fix
  • docs: Documentation
  • chore: Maintenance

4. Creating Releases

# Tag new version
git tag -a v1.0.0 -m "Release version 1.0.0"
git push origin v1.0.0

Troubleshooting

Common Issues

1. Asset Not Found:

   • Check asset file naming
   • Verify module is in correct directory

2. Resource Configuration:

   • Verify resource config in deployment
   • Check Kubernetes secrets if needed

3. Docker Build Fails:

   • Check dependency versions
   • Verify system requirements

Logs

# Get dagster logs
kubectl logs -l app=dagster-user-deployments

# Check deployment status
kubectl describe userdeployment my-workflow

Contributing

Contributions Welcome

License

MIT License - See LICENSE file for details