Node-RED S3 Context Storage

A Node-RED context storage implementation that uses AWS S3 as the backend storage for persistent context data.

Overview

This module provides a context storage implementation for Node-RED that stores context data in AWS S3 buckets. It implements the Node-RED context API and allows you to persist context data across Node-RED restarts using Amazon S3 as the storage backend.

Features

• Persistent Storage: Context data is stored in AWS S3, ensuring data persistence
• Scope Support: Supports different context scopes (global, flow, node)
• JSON Storage: Data is stored as JSON objects in S3
• AWS SDK Integration: Uses the official AWS SDK for JavaScript v3
• Error Handling: Proper error handling for S3 operations

Installation

npm install node-red-context-s3

Configuration

To use this context storage in your Node-RED application, add the following to your settings.js file:

module.exports = {
    // ... other settings ...
    
    contextStorage: {
        s3: {
            module: "node-red-context-s3",
            config: {
                bucket: "your-s3-bucket-name",
                prefix: "node-red", // optional prefix for S3 keys
                flushInterval: 5,    // optional flush interval in seconds
                // AWS credentials configuration
                region: "us-east-1",
                credentials: {
                    accessKeyId: "your-access-key",
                    secretAccessKey: "your-secret-key"
                }
            }
        }
    },
    
    // Set S3 as the default context storage
    defaultContextStorage: "s3"
};

AWS Credentials

The module uses the AWS SDK for JavaScript v3. You can provide credentials in several ways:

1. Direct configuration (as shown above)
2. Environment variables: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION
3. AWS credentials file: ~/.aws/credentials
4. IAM roles (when running on EC2 or ECS)

API Methods

This module implements the standard Node-RED context API:

get(scope, keys, callback)

Retrieves context values for the specified scope and keys.

set(scope, keys, values, callback)

Sets context values for the specified scope and keys.

keys(scope, callback)

Returns all keys available in the specified scope.

delete(scope)

Deletes all context data for the specified scope.

clean(scopes)

Cleans context data for multiple scopes.

S3 Storage Structure

Context data is stored in S3 with the following key structure:

{prefix}/context/{scope}.json

Example:

• node-red/context/global.json
• node-red/context/flow:abc123.json
• node-red/context/node:xyz789.json

Each scope is stored as a separate JSON object in the S3 bucket.

Testing

To run the tests:

npm test

Make sure to set up your AWS credentials and configure a test S3 bucket before running tests.

Dependencies

• @aws-sdk/client-s3: AWS SDK for S3 operations
• jest: Testing framework
• dotenv: Environment variable management for tests

License

MIT License - see LICENSE file for details

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.