GraphXR Spanner Graph Connector

A FastAPI-based service that enables GraphXR to connect and visualize graph data stored in Google Cloud Spanner Graph. This API service acts as a bridge between GraphXR and Spanner Graph, allowing interactive graph data exploration and visualization.

Prerequisites

• Google Cloud Platform account
• Google Cloud Spanner instance
• Google Cloud credentials (credentials.json)

Project Setup

1. Clone the repository
2. Place your credentials.json file in the project root directory
3. Create a .env file with the following variables or set them in the docker-compose.yml file:

ENVIRONMENT=development
SPANNER_INSTANCE=transit
SPANNER_DATABASE=transitdb
GOOGLE_CLOUD_PROJECT=code4demo
GRAPH_NAME=TransitGraph

Running the Application

Using Docker Compose (Recommended)

1. Build and start the container:

docker-compose up --build

The API will be available at http://localhost:8000

Manual Setup

1. Create a virtual environment:

python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

2. Install dependencies:

pip install -r requirements.txt

3. Run the application:

uvicorn main:app --host 0.0.0.0 --port 8000 

Connect Spanner Graph with GraphXR Grove

To connect the API with GraphXR Grove, follow these steps:

1. Access GraphXR Grove through one of these options:

   • Use the shared demo link: Spanner Graph Transit Demo

   Notice: The demo link uses a trial database which may not always be accessible. If you encounter connection issues, please set up your own project following the instructions below.

   • Create your own project in GraphXR Grove

2. If creating your own project:

   • Open GraphXR
   • Create a new project
   • In the Grove panel:
     • Import spanner-graph.grove
     • Connect to http://localhost:8000 using the Grove

3. You should see a UI like this:

API Endpoints

• GET /api/v1/spanner/schema: Retrieve database schema information
• POST /api/v1/spanner/execute: Execute graph queries
• GET /api/v1/spanner/samples: Get predefined query samples

Environment Variables

Variable	Description	Default
ENVIRONMENT	Application environment	development
SPANNER_INSTANCE	Google Cloud Spanner instance name	transit
SPANNER_DATABASE	Spanner database name	transitdb
GOOGLE_CLOUD_PROJECT	Google Cloud project ID	-
GRAPH_NAME	Name of the graph in Spanner	TransitGraph

Project Structure

.
├── main.py              # FastAPI application entry point
├── routes/              # API route handlers
├── models/              # Pydantic models
├── docker-compose.yml   # Docker compose configuration
├── Dockerfile          # Docker build instructions
├── requirements.txt    # Python dependencies
└── samples.yaml        # Sample queries configuration

Data Source

The demo data used in this project is sourced from TransitFraudDemo, which provides sample transit data for demonstration purposes.

Security Notes

• The application currently allows all CORS origins (*)
• Ensure your credentials.json is properly secured and not committed to version control
• Review the .gitignore file to ensure sensitive files are not tracked