Logs Data Platform - Getting started with Node.js

Objective

This guide allows you to send logs from a Node.js application to Logs Data Platform (LDP). We will use the Pino logger, a fast and low-overhead logger for Node.js, combined with a GELF (Graylog Extended Log Format) transport. It's also possible to use Winston logger with a GELF transport, instructions are provided at the end of this guide.

Requirements

• A Logs Data Platform account.
• A Stream created and its Token (X-OVH-TOKEN).
• The address of your LDP cluster (e.g., gra1.logs.ovh.com) and the GELF port (usually 12202 for TLS).
• Node.js installed on your environment (version >= 20 recommended).

Instructions for logging with Pino

Install Dependencies

We need two packages:

• pino: Encodes logs to JSON.
• @alex-michaud/pino-graylog-transport: Sends the logs to the LDP endpoint using GELF.

Install them via npm:

npm install pino @alex-michaud/pino-graylog-transport

Configure the Logger

Create a file named logger.js (or index.js) and configure the logger.

You need to:

1. Configure the transport to point to your LDP cluster.
2. Add your X-OVH-TOKEN to every log message so LDP accepts and routes them. In GELF, custom fields generally start with an underscore _.

import { pino } from 'pino'
import { PinoGraylogTransport } from '@alex-michaud/pino-graylog-transport'

// Replace these values with your specific configuration
const LDP_CLUSTER = 'gra1.logs.ovh.com'; // Your cluster address
const LDP_PORT = 12202;                  // GELF TLS port
const LDP_TOKEN = 'your-data-stream-write-token';   // X-OVH-TOKEN

// Create a promise to wait for the transport to be ready
let resolveReady, rejectReady;
const isReady = new Promise((resolve, reject) => {
    resolveReady = resolve;
    rejectReady = reject;
});

const pinoGraylogTransportOptions = {
    host: LDP_CLUSTER,
    port: LDP_PORT,
    protocol: 'tls',
    staticMeta: { 'X-OVH-TOKEN': LDP_TOKEN, }, // Note: no underscore - GELF formatter adds it
    onReady: (success, err) => {
        if (success) {
            console.log('Graylog transport connected successfully');
            resolveReady();
            return;
        }
        console.error('Graylog transport failed to connect:', err);
        rejectReady(err);
    },
}

const pinoGraylogTransport = new PinoGraylogTransport(pinoGraylogTransportOptions);

const logger = pino({ level: 'info' }, pinoGraylogTransport);

(async () => {
    try {
        // Wait until the logger is ready
        await isReady;
        console.log('Logger is ready to send logs');

        // Usage examples
        logger.info('Hello! This is a test log from Node.js');
        logger.warn({ user_id: 42 }, 'User performed a restricted action');
        logger.error(new Error('Something went wrong'), 'An error occurred');

        await pinoGraylogTransport.flush();

        console.log('Logger has terminated');
    } catch (err) {
        console.error('Logger error:', err);
        process.exit(1);
    }
})();

Run and Verify

Run your application:

node logger.js

Then, go to your Graylog interface (access via the OVHcloud Control Panel]) and define a relative search time (e.g., "Last 5 minutes"). You should see your messages appearing in the stream.

Go further

• Pino Documentation
• @alex-michaud/pino-graylog-transport Documentation
• Graylog Extended Log Format (GELF)

Instructions for logging with Winston

Install Dependencies

We need two packages:

• winston: A versatile logging library for Node.js.
• winston-log2gelf: A transport for Winston to send logs in GELF format.

Install them via npm:

npm install winston winston-log2gelf

Configure the Logger

Create a file named logger.js (or index.js) and configure the logger.

You need to:

1. Configure the transport to point to your LDP cluster.
2. Add your X-OVH-TOKEN to every log message so LDP accepts and routes them. In GELF, custom fields generally start with an underscore _.
3. Set the log level as needed.

import { createLogger } from 'winston';
import Log2gelf from 'winston-log2gelf';

// Replace these values with your specific configuration
const LDP_CLUSTER = 'gra1.logs.ovh.com'; // Your cluster address
const LDP_PORT = 12202;                  // GELF TLS port
const LDP_TOKEN = 'your-data-stream-write-token';   // X-OVH-TOKEN

const gelfTransport = new Log2gelf({
    level: "info",
    host: LDP_CLUSTER,
    port: LDP_PORT,
    protocol: "tls",
});

const logger = createLogger({
    exitOnError: false,
    level: 'info',
    transports: [
        gelfTransport
    ],
    defaultMeta: { 'X-OVH-TOKEN': LDP_TOKEN },
});

// Listen for errors
logger.on('error', (error) => {
    console.error('Logger error event:', error);
});

(async () => {
    try {
        console.log('Sending logs...');

        // Usage examples
        logger.info('Hello! This is a test log from Node.js with Winston');
        logger.warn('User performed a restricted action', { user_id: 42 });
        logger.error('An error occurred', new Error('Something went wrong'));

        // Wait for logs to be sent - Log2gelf needs time to process
        await new Promise(resolve => setTimeout(resolve, 1000));

        console.log('All logs sent successfully');
        process.exit(0);
    } catch (err) {
        console.error('Logger error:', err);
        process.exit(1);
    }
})();

Run and Verify

Run your application:

node logger.js

Then, go to your Graylog interface (access via the OVHcloud Control Panel) and define a relative search time (e.g., "Last 5 minutes"). You should see your messages appearing in the stream.

• Winston Documentation
• Winston-log2gelf Documentation
• Graylog Extended Log Format (GELF)

Go further

• Getting Started: Quick Start
• Documentation: Guides
• Create an account: Try it!

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