# Turbine

A modular service framework.

## Registrar

The Registrar is the service discovery system of the DysonNetwork.
Here are a port to the Golang in order to support other Golang services.

To use the system, try build with these API:

```go
package main

import (
	"log"
	"os"
	"os/signal"
	"syscall"

	"yourmodule/registry"
)

func main() {
	endpoints := []string{"localhost:2379"}

	registrar, err := registry.NewServiceRegistrar(endpoints)
	if err != nil {
		log.Fatalf("Error creating registrar: %v", err)
	}

	serviceName := "orders"
	host := "10.0.0.5"
	port := 5000
	ttl := int64(30)

	err = registrar.Register(serviceName, "http", "instance-1", host, port, ttl)
	if err != nil {
		log.Fatalf("Register error: %v", err)
	}
	log.Println("Service registered")

	// Wait for termination
	stop := make(chan os.Signal, 1)
	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
	<-stop

	err = registrar.Deregister()
	if err != nil {
		log.Printf("Deregister error: %v", err)
	} else {
		log.Println("Service deregistered")
	}
}
```

## Gateway

The gateway is the entry point for all requests. It uses the `registrar` to discover services in real-time from etcd and forwards requests to the appropriate service instances.

### Features
- **Service Discovery**: Automatically discovers `http` services from etcd.
- **Dynamic Routing**: Maintains an in-memory routing table that is automatically updated when services are added or removed.
- **Request Proxying**: Forwards incoming requests to the correct service instance based on the URL path (`/<service-name>/...`).
- **Load Balancing**: Implements round-robin load balancing across service instances.
- **Route Overrides**: Allows for custom routing rules to be defined in the configuration file.

### Configuration

The gateway is configured via a `settings.toml` file located in the same directory.

```toml
# The address the gateway will listen on
listen = ":8080"

# ETCD configuration for service discovery
[etcd]
endpoints = ["127.0.0.1:2379"]
# Set to true if your etcd server does not use TLS
insecure = true

# Custom route overrides
# The key is the incoming path prefix.
# The value is the destination in the format "/<service_name>/<path_prefix>"
[routes]
"/websocket" = "/chatter/ws"
```

## Config Service

The config service provides a centralized location for other services to fetch their configuration. This is useful for managing connection strings, feature flags, and other shared parameters without hardcoding them into each service.

### Usage
The config service reads a `shared_config.toml` file from its own directory (`pkg/config`) and serves it as a JSON object over a simple HTTP endpoint.

To retrieve the configuration, other services can make a GET request to the gateway at `/config`. The gateway will route the request to an available instance of the config service.

**Example with curl:**
```bash
curl http://localhost:8080/config
```

**Expected Response (JSON):**
```json
{
  "database": {
    "connection_string": "postgres://user:password@db-host:5432/mydatabase?sslmode=require"
  },
  "redis": {
    "address": "redis-host:6379"
  }
}
```