rules

Rules Engine

This project implements a flexible and extensible rules engine using the Common Expression Language (CEL) for policy and rule evaluation. It provides a NATS-based API for managing policies and rules, and integrates with NATS JetStream for event-driven policy evaluation.

Features

• Define and manage policies and rules using CEL expressions
• NATS JetStream-based API for policy management (set, list, get, delete)
• Protocol Buffers for message serialization
• protovalidate for request validation
• NATS JetStream integration for event-driven policy evaluation
• Flexible configuration using environment variables
• Comprehensive test coverage

Getting Started

Prerequisites

• Go 1.16 or later
• NATS server with JetStream enabled
• Protocol Buffers compiler (protoc)
• buf (for managing Protocol Buffers)

Installation

1. Clone the repository:

   git clone https://github.com/sandrolain/rules.git
   cd rules
   

2. Install dependencies:

   go mod download
   

3. Generate Protocol Buffer code:

   make proto
   

Configuration

The application can be configured using environment variables:

• NATS_URL: NATS server URL (default: "nats://localhost:4222")
• NATS_INPUT_SUBJECT: NATS subject for input messages (default: "rules.engine.input")
• NATS_OUTPUT_SUBJECT: NATS subject for output messages (default: "rules.engine.output")
• NATS_INPUT_STREAM: NATS JetStream name for input (default: "RULES_INPUT")
• NATS_OUTPUT_STREAM: NATS JetStream name for output (default: "RULES_OUTPUT")
• LOG_LEVEL: Logging level (debug, info, warn, error; default: info)

Running the Application