# API Logger Middleware with MongoDB And Kafka.

A lightweight logging library for Express applications that supports both MongoDB and Kafka for log storage and streaming. Automatically logs API requests and provides functionality for manual logging.

## Features
- Logs incoming API requests and outgoing responses
- Captures request/response bodies and headers
- Saves logs to MongoDB
- Custom logger function for manual log entries
- Optional Kafka integration for log streaming
- Automatic Kafka topic creation and consumption



## Installation
```bash
npm install @shivamjha1288/logs-manager
```

## Usage

### 1. Initialize the Logging System
```js
import { logsInit } from "./your-log-file.js";

await logsInit({
  appName: "your-app-name",
  mongoUrl: "mongodb://localhost:27017/logsdb",
  enableKafka: true,
  kafkaConfig: {
    clientId: "your-app",
    brokers: ["localhost:9092"],
    groupId: "logs-group",
    topicConfig: {
      topicName: "logs-topic",
      numPartitions: 1,
      replicationFactor: 1,
    },
  },
});

```

### 2.  Use as Middleware in Express
```js
import express from "express";
import { apiRequestLogger } from "./your-log-file.js";

const app = express();
app.use(express.json());
app.use(apiRequestLogger());

```

### 3. Manually Log Data
```js
import { logData } from "./your-log-file.js";

await logData("error", "Something went wrong", {
  error: { message: "Example error" },
});

```

### 4. Full Example
```js
import express from "express";
import { logsInit, apiRequestLogger, logData } from "@shivamjha1288/logs-manager";

const app = express();
const port = 3000;
const mongoUrl = "mongodb://admin:admin@localhost:27017/logs?authSource=admin";
const appName = "test-logs";
const kafkaConfig={
  clientId:"logsapp",
  brokers:["localhost:9092"],
  topicConfig:{
    topicName:"logs-topic",
    partition:1,
    replicationFactor:1
  },
  groupId:"logs-group"
}

logsInit({
  appName,
  mongoUrl,
  enableKafka: true,
  kafkaConfig
});

app.use(express.json());
app.use(apiRequestLogger(mongoUrl));

app.get("/", (req, res) => {
  res.send("Hello from test app!");
});
app.get("/error", (req, res) => {
  res.status(500).json({ staus: 500, error: "Internal server error" });
});

app.post("/log", async (req, res) => {
  await logData(mongoUrl, "info", "Manually logged from /log route", {
    body: req.body,
  });
  res.send("Custom log saved.");
});

app.listen(port, () => {
  console.log(`http://localhost:${port}`);
});
```

## Log Schema Fields
- `appName`: Application identifier (string, required)
- `level`: Log level (`info`, `error`, etc.)
- `message`: Log message
- `timestamp`: Date and time
- `method`: HTTP method (GET, POST, etc.)
- `url`: Request URL
- `statusCode`: HTTP status code
- `responseTime`: Time taken for response (ms)
- `requestBody`: Body of the request
- `requestHeaders`: Request headers
- `responseBody`: Body of the response
- `responseHeaders`: Response headers
- `error`: Error object if any


## Dependencies
- [mongoose](https://www.npmjs.com/package/mongoose)
- [kafkajs](https://www.npmjs.com/package/kafkajs)

## License
ISC