Real-time logging with Grafana in Node.js applications

01 Oct 2023

Introduction

Logging is an essential aspect of any application as it allows developers to track and analyze the behavior of their code in real-time. In this blog post, we will explore how to implement real-time logging in Node.js applications using Grafana, a popular open-source logging and monitoring solution.

Prerequisites

To follow along with this tutorial, you will need:

Node.js installed on your machine
Grafana configured and running

Setting up the environment

First, let’s set up our Node.js environment and install the necessary dependencies. Open your terminal and create a new project directory by executing the following command:

mkdir realtime-logging
cd realtime-logging

Initialize a new Node.js project by running:

npm init -y

Next, install the required dependencies by executing:

npm install express morgan grafana-datasource-kit

Implementing real-time logging

To implement real-time logging in a Node.js application, we need to use the Grafana Data Source Kit (DSK) library, which provides an interface to interact with Grafana’s backend.

First, let’s create a new file called index.js and add the following code:

const express = require('express');
const morgan = require('morgan');
const { GrafanaDataSource } = require('grafana-datasource-kit');

const app = express();
const port = 3000;

// Enable logging middleware
app.use(morgan('combined'));

// Initialize the GrafanaDataSource
const dataSource = new GrafanaDataSource({
  url: 'http://localhost:3000/grafana/api',
  username: 'admin',
  password: 'password',
  dataSourceId: 1,
});

// Define an API endpoint for logging
app.get('/log', async (req, res) => {
  const { level, message } = req.query;

  try {
    // Send the log message to Grafana
    await dataSource.writeLog(level, message);
    res.sendStatus(200);
  } catch (error) {
    console.error('Error writing log:', error);
    res.sendStatus(500);
  }
});

// Start the server
app.listen(port, () => {
  console.log(`Server running on port ${port}`);
});

In the code above, we import the necessary packages (express, morgan, and grafana-datasource-kit) and initialize an Express.js application. We also configure the logging middleware using morgan.

We create an instance of GrafanaDataSource and provide the Grafana URL, username, password, and the ID of the data source we want to use. Modify these values according to your Grafana setup.

We define an API endpoint /log that accepts level and message query parameters. Inside the endpoint, we use the writeLog method of GrafanaDataSource to send the log message to Grafana.

Finally, we start the server and listen on port 3000.

Conclusion

In this tutorial, we explored how to implement real-time logging in Node.js applications using Grafana. By logging events and messages in real-time, you can gain valuable insights into your application’s behavior and quickly identify and fix issues. Incorporating Grafana’s powerful monitoring capabilities ensures that you have a robust and efficient logging solution for your Node.js applications.

#grafana #logging