LeoTrace.Core 1.0.36

LeoTrace

Distributed HTTP request tracing for .NET and Node.js — streams live traces to a real-time dashboard via SignalR.

✨ What is LeoTrace?

LeoTrace automatically captures every incoming and outgoing HTTP request in your services, records them to a database, and streams them live to a central dashboard — all with zero manual instrumentation.

Your Service (C#/.NET or Node.js)
    ↓  auto-captured by middleware
LeoTrace.Server (dashboard + API)
    ↓  real-time push via SignalR
Browser Dashboard → live trace timeline

🚀 Quick Start

1. Run the LeoTrace Server

docker run -d \
  -p 5050:5050 \
  -e LeoTrace__Storage__Provider=MongoDb \
  -e LeoTrace__Storage__MongoConnectionString=mongodb://mongo:27017 \
  --name leotrace-server \
  leventleo/leotrace-server:latest

Dashboard → http://localhost:5050

Or with Docker Compose:

docker compose -f docker-compose.yml up -d

2a. .NET / ASP.NET Core Integration

dotnet add package LeoTrace.Core
dotnet add package LeoTrace.Storage

// Program.cs
builder.Services.Configure<LeoTraceOptions>(builder.Configuration.GetSection("LeoTrace"));
builder.Services.AddLeoTraceStorage();
builder.Services.AddLeoTrace(opt =>
{
    opt.ServiceName = "OrderService";
    opt.ExcludedPaths = ["/health", "/metrics"];
});

var app = builder.Build();
app.UseLeoTrace(); // ← add before MapControllers
app.MapControllers();
app.Run();

// appsettings.json
{
  "LeoTrace": {
    "ServiceName": "OrderService",
    "ServerUrl": "http://localhost:5050",
    "Storage": {
      "Provider": "MongoDb",
      "MongoConnectionString": "mongodb://localhost:27017",
      "MongoDatabaseName": "leotrace"
    }
  }
}

2b. Node.js / Express Integration

npm install leotrace-node

const express = require('express');
const { createLeoTrace } = require('leotrace-node');

const app = express();
const leo = createLeoTrace({
  serverUrl:   'http://localhost:5050',
  serviceName: 'express-api',
});

app.use(leo.expressMiddleware()); // ← before your routes

app.get('/users', (req, res) => res.json([{ id: 1 }]));
app.listen(3000);

2c. Next.js Integration

App Router:

// app/api/orders/route.js
import { createLeoTrace } from 'leotrace-node';
const leo = createLeoTrace({ serverUrl: 'http://localhost:5050', serviceName: 'nextjs-app' });
export const GET = leo.withLeoTrace(async (req) => Response.json({ orders: [] }));

Pages Router:

// pages/api/products.js
import { createLeoTrace } from 'leotrace-node';
const leo = createLeoTrace({ serverUrl: 'http://localhost:5050', serviceName: 'nextjs-app' });
export default leo.withLeoTraceApi(async (req, res) => res.json({ products: [] }));

2d. Nuxt 3 Integration

// server/middleware/leotrace.js
import { createLeoTrace } from 'leotrace-node';
const leo = createLeoTrace({ serverUrl: 'http://localhost:5050', serviceName: 'nuxt-app' });
export default leo.nuxtMiddleware();

⚙️ Configuration Reference

.NET LeoTraceOptions

Node.js createLeoTrace Options

🗄️ Supported Storage Backends

Storage is auto-detected from connection strings. If none found, SQLite is used as fallback.

🔄 Distributed Trace Propagation

When requests flow through multiple services, LeoTrace links them via X-Trace-Id header:

Client → ServiceA (TraceId=abc) → ServiceB (TraceId=abc) → ServiceC (TraceId=abc)
                                     ↓ All appear as one unified flow in dashboard

This propagation is automatic in both .NET (LeoTraceHandler) and Node.js SDK.

🎯 Replay & Simulate

From the dashboard or REST API:

# Re-execute a real HTTP request
POST /api/replay/{stepId}?traceId={traceId}

# Replay without making a real request (simulated)
POST /api/replay/{stepId}/simulate?traceId={traceId}

🐳 Docker Compose (Full Stack)

docker compose up -d

See docker-compose.yml in the repository root.

📄 License

MIT © Levent Topcu