Kessel SDK for Python

A Python gRPC library for connecting to Project Kessel services. This provides the foundational gRPC client library for Kessel Inventory API, with plans for a higher-level SDK with fluent APIs, OAuth support, and advanced features in future releases.

Installation

Install the package using pip:

pip install kessel-sdk

Usage

This library provides direct access to Kessel Inventory API gRPC services. All generated classes are available under the kessel.inventory module.

Basic Example - Check Permissions

import grpc
from kessel.inventory.v1beta2 import (
    inventory_service_pb2_grpc,
    check_request_pb2,
    resource_reference_pb2,
    reporter_reference_pb2,
    subject_reference_pb2,
)

# Create gRPC client (insecure for development)
stub = inventory_service_pb2_grpc.KesselInventoryServiceStub(
    grpc.insecure_channel("localhost:9000")
)

# Create subject reference
subject = subject_reference_pb2.SubjectReference(
    resource=resource_reference_pb2.ResourceReference(
        reporter=reporter_reference_pb2.ReporterReference(type="rbac"),
        resource_id="alice",
        resource_type="principal"
    )
)

# Create resource reference
resource_ref = resource_reference_pb2.ResourceReference(
    resource_id="alice_club",
    resource_type="group",
    reporter=reporter_reference_pb2.ReporterReference(type="rbac"),
)

# Check permissions
try:
    response = stub.Check(
        check_request_pb2.CheckRequest(
            subject=subject,
            relation="member",
            object=resource_ref,
        )
    )
    print(f"Permission check result: {response.allowed}")
except grpc.RpcError as e:
    print(f"Error: {e.details()}")

Report Resource Example

import grpc
from google.protobuf import struct_pb2
from kessel.inventory.v1beta2 import (
    inventory_service_pb2_grpc,
    report_resource_request_pb2,
    resource_representations_pb2,
    representation_metadata_pb2,
)

stub = inventory_service_pb2_grpc.KesselInventoryServiceStub(
    grpc.insecure_channel("localhost:9000")
)

# Build protobuf Struct for common metadata
common_struct = struct_pb2.Struct()
common_struct.update({"workspace_id": "6eb10953-4ec9-4feb-838f-ba43a60880bf"})

# Build protobuf Struct for reporter-specific data  
reporter_struct = struct_pb2.Struct()
reporter_struct.update({
    "satellite_id": "ca234d8f-9861-4659-a033-e80460b2801c",
    "sub_manager_id": "e9b7d65f-3f81-4c26-b86c-2db663376eed",
    "insights_inventory_id": "c4b9b5e7-a82a-467a-b382-024a2f18c129",
    "ansible_host": "host-1",
})

# Create metadata for the resource representation
metadata = representation_metadata_pb2.RepresentationMetadata(
    local_resource_id="854589f0-3be7-4cad-8bcd-45e18f33cb81",
    api_href="https://apiHref.com/",
    console_href="https://www.consoleHref.com/",
    reporter_version="0.2.11",
)

# Build the resource representations
representations = resource_representations_pb2.ResourceRepresentations(
    metadata=metadata,
    common=common_struct,
    reporter=reporter_struct
)

# Create the report request
request = report_resource_request_pb2.ReportResourceRequest(
    type="host",
    reporter_type="hbi",
    reporter_instance_id="0a2a430e-1ad9-4304-8e75-cc6fd3b5441a",
    representations=representations,
)

try:
    response = stub.ReportResource(request)
    print("Resource reported successfully")
except grpc.RpcError as e:
    print(f"Error reporting resource: {e.details()}")

Available Services

The library includes the following gRPC services:

• KesselInventoryService: Main inventory service
  • Check(CheckRequest) - Check permissions
  • CheckForUpdate(CheckForUpdateRequest) - Check for resource updates
  • ReportResource(ReportResourceRequest) - Report resource state
  • DeleteResource(DeleteResourceRequest) - Delete a resource
  • StreamedListObjects(StreamedListObjectsRequest) - Stream resource listings

Generated Classes

All protobuf message classes are generated and available. Key classes include:

• CheckRequest, CheckResponse
• ReportResourceRequest, ReportResourceResponse
• DeleteResourceRequest, DeleteResourceResponse
• ResourceReference, SubjectReference
• ResourceRepresentations, RepresentationMetadata

See the examples/ directory for complete working examples.

Authentication

The SDK supports OAuth 2.0 Client Credentials flow for authentication with Kessel services. The OAuth2ClientCredentials class provides automatic token management with built-in refreshing.

Note: To use authentication features, install the SDK with auth dependencies: pip install "kessel-sdk[auth]"

Development

Prerequisites

• Python 3.11 or higher
• buf for protobuf/gRPC code generation

Install buf:

# On macOS
brew install bufbuild/buf/buf

# On Linux
curl -sSL "https://github.com/bufbuild/buf/releases/latest/download/buf-$(uname -s)-$(uname -m)" -o "/usr/local/bin/buf" && chmod +x "/usr/local/bin/buf"

# Or see https://docs.buf.build/installation for other options

Setup

# Install additional development dependencies
pip install "kessel-sdk[dev]"

# Generate gRPC code from Kessel Inventory API
buf generate

Code Generation

This library uses buf to generate Python gRPC code from the official Kessel Inventory API protobuf definitions hosted at buf.build/project-kessel/inventory-api.

The generation is configured in buf.gen.yaml.

To regenerate the code:

buf generate

This will download the latest protobuf definitions and generate fresh Python classes in the src/ directory.

Building and Installing Locally

# Build and install the package locally
pip install -e .

Code Quality

Format and lint excluding generated gRPC files (*_pb2.py and *_pb2_grpc.py):

# Auto-format source & examples
black --exclude '.*_pb2(_grpc)?\.py' src/ examples/

# Lint source & examples
flake8 --exclude '*_pb2.py,*_pb2_grpc.py' src/ examples/

Testing

Run tests using pytest:

# Run all tests
pytest

Examples

The examples/ directory contains working examples:

• auth.py - OAuth 2.0 authentication via a secure connection
• auth_insecure.py - OAuth 2.0 authentication via an insecure connection
• check.py - Permission checking
• report_resource.py - Reporting resource state
• delete_resource.py - Deleting resources
• check_for_update.py - Checking for updates
• streamed_list_objects.py - Streaming resource lists

Run examples:

python -m examples.check

Error Handling

The SDK uses standard gRPC status codes:

try:
    resp = stub.Check(request)
except grpc.RpcError as err:
    if err.code() == grpc.StatusCode.PERMISSION_DENIED:
        print("Permission denied")
    elif err.code() == grpc.StatusCode.UNAVAILABLE:
        print("Service unavailable")
    else:
        print(f"Error: {err.details()}")

Roadmap

This is the foundational gRPC library. Future releases will include:

• High-level SDK: Fluent client builder API
• Convenience Methods: Simplified APIs for common operations

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -am 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Release Instructions

This section provides step-by-step instructions for maintainers to release a new version of the Kessel SDK for Python.

Version Management

This project follows Semantic Versioning 2.0.0. Version numbers use the format MAJOR.MINOR.PATCH:

• MAJOR: Increment for incompatible API changes
• MINOR: Increment for backward-compatible functionality additions
• PATCH: Increment for backward-compatible bug fixes

Note: SDK versions across different languages (Ruby, Python, Go, etc.) do not need to be synchronized. Each language SDK can evolve independently based on its specific requirements and release schedule.

Prerequisites for Release

• Write access to the GitHub repository
• PyPI account with publish access to the kessel-sdk package
• Ensure quality checks are passing
• Review and update CHANGELOG or release notes as needed
• Python 3.11 or higher
• Required tools installed:

  pip install build twine
  pip install "kessel-sdk[dev]"

• buf for protobuf/gRPC code generation:

  # On macOS
  brew install bufbuild/buf/buf
  
  # On Linux
  curl -sSL "https://github.com/bufbuild/buf/releases/latest/download/buf-$(uname -s)-$(uname -m)" -o "/usr/local/bin/buf" && chmod +x "/usr/local/bin/buf"

Release Process

1. Update the Version

# Edit pyproject.toml
# Update the version field to the new version number
vim pyproject.toml

2. Update Dependencies (if needed)

# Regenerate gRPC code if there are updates to the Kessel Inventory API
buf generate

3. Run Quality Checks

# Format code (excluding generated files)
black --exclude '.*_pb2(_grpc)?\.py' src/ examples/

# Run linting (excluding generated files)
flake8 --exclude '*_pb2.py,*_pb2_grpc.py' src/ examples/

# Test that examples can be imported without errors
python -c "import examples.check"
python -c "import examples.auth"

# Build the project
python -m build

4. Commit and Push Changes

# Commit the version bump and any related changes
git add pyproject.toml
git commit -m "chore: bump version to X.Y.Z"
git push origin main # or git push upstream main

5. Build and Publish the Package

# Clean any previous build artifacts
rm -rf dist/ build/

# Build the package
python -m build

# Publish to PyPI (requires PyPI account and package access)
twine upload dist/*

6. Tag the Release

# Create and push a git tag
git tag -a vX.Y.Z -m "Release version X.Y.Z"
git push origin vX.Y.Z

7. Create GitHub Release

• Go to the GitHub Releases page
• Click "Create a new release"
• Select the tag you just created
• Add release notes describing the changes
• Publish the release

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.