Send logs from Node.js

Send Node.js logs to Rootprint over OTLP HTTP with the OpenTelemetry SDK, Pino, or Winston.

Prerequisites

A running Rootprint instance. Substitute its host for <your-rootprint>.
Node.js 22+ with npm. The examples are ES modules with top-level await: save them as .mjs, or set "type": "module" in package.json.
An ingest API key scoped to an OpenTelemetry logs index such as otel-logs-v0_9. In Settings → API keys, click Create ingest key and pick the index. See API keys.

Setup

Install

OpenTelemetry SDK
Pino
Winston

npm install @opentelemetry/api-logs @opentelemetry/sdk-logs @opentelemetry/exporter-logs-otlp-proto @opentelemetry/resources

npm install pino pino-opentelemetry-transport

npm install winston @opentelemetry/api-logs @opentelemetry/sdk-logs @opentelemetry/exporter-logs-otlp-proto @opentelemetry/winston-transport @opentelemetry/resources

Set environment variables

export OTEL_SERVICE_NAME=my-node-service
export OTEL_EXPORTER_OTLP_LOGS_ENDPOINT='https://<your-rootprint>/v1/logs'
export OTEL_EXPORTER_OTLP_LOGS_HEADERS='Authorization=Bearer%20<your-ingest-api-key>'

The %20 after Bearer is required: OpenTelemetry SDKs expect URL-encoded values in OTEL_EXPORTER_OTLP_LOGS_HEADERS.

Minimal working example

OpenTelemetry SDK
Pino
Winston

import { logs } from '@opentelemetry/api-logs';
import { LoggerProvider, BatchLogRecordProcessor } from '@opentelemetry/sdk-logs';
import { OTLPLogExporter } from '@opentelemetry/exporter-logs-otlp-proto';
import { defaultResource, detectResources, envDetector } from '@opentelemetry/resources';

// Pick up service.name (and anything in OTEL_RESOURCE_ATTRIBUTES) from the environment
const resource = defaultResource().merge(
    detectResources({ detectors: [envDetector] })
);

const provider = new LoggerProvider({
    resource,
    processors: [new BatchLogRecordProcessor({ exporter: new OTLPLogExporter() })]
});

logs.setGlobalLoggerProvider(provider);

logs.getLogger('hello').emit({ severityText: 'INFO', body: 'Hello from Node to Rootprint' });

// Flush buffered records before a short-lived script exits.
await provider.shutdown();

import pino from 'pino';

const transport = pino.transport({
    target: 'pino-opentelemetry-transport'
});

const log = pino(transport);
log.info('Hello from Pino to Rootprint');

// Flush buffered records before a short-lived script exits.
transport.end();

import { logs } from '@opentelemetry/api-logs';
import { LoggerProvider, BatchLogRecordProcessor } from '@opentelemetry/sdk-logs';
import { OTLPLogExporter } from '@opentelemetry/exporter-logs-otlp-proto';
import { defaultResource, detectResources, envDetector } from '@opentelemetry/resources';
import { OpenTelemetryTransportV3 } from '@opentelemetry/winston-transport';
import winston from 'winston';

const resource = defaultResource().merge(
    detectResources({ detectors: [envDetector] })
);

const provider = new LoggerProvider({
    resource,
    processors: [new BatchLogRecordProcessor({ exporter: new OTLPLogExporter() })]
});

logs.setGlobalLoggerProvider(provider);

const logger = winston.createLogger({
    level: 'info',
    transports: [new OpenTelemetryTransportV3()]
});

logger.info('Hello from Winston to Rootprint');

// Flush buffered records before a short-lived script exits.
await provider.shutdown();

Verify in Rootprint

Open Logs, filter on service_name:my-node-service, and your record should appear within a few seconds.

Structured logging

Pass attributes with the record. You can search and filter on them in Rootprint.

logs.getLogger('app').emit({
	severityText: 'INFO',
	body: 'user signed up',
	attributes: { user_id: 'alice', plan: 'pro' }
});

With Pino, pass an object as the first argument:

log.info({ user_id: 'alice', plan: 'pro' }, 'user signed up');

Framework recipe: Express

Initialize the SDK once at process start. Move the provider setup from the OpenTelemetry SDK example, from the imports through logs.setGlobalLoggerProvider(provider), into otel.js, and export a logger from it:

// otel.js (after the provider setup)
export const logger = logs.getLogger('express-app');

Import it before your Express app:

// server.js
import { logger } from './otel.js';
import express from 'express';

const app = express();

app.use((req, _res, next) => {
	logger.emit({
		severityText: 'INFO',
		body: 'request',
		attributes: { method: req.method, path: req.path }
	});
	next();
});

app.get('/', (_req, res) => res.json({ ok: true }));
app.listen(3000);

Troubleshooting

401 or 403: the ingest API key is missing or wrong, or the space after Bearer isn’t written as %20. Check OTEL_EXPORTER_OTLP_LOGS_HEADERS. See Response codes.
200 but no records in Logs: the ingest API key is scoped to an index without the OpenTelemetry logs schema, so the records are discarded. See Index target.
Nothing in Logs from a short-lived script: the batch processor buffers records. Shut down the logger provider before exit, as the minimal example does.
Every Winston line stored twice: the app also runs under the auto-instrumentation register hook from Send traces, which adds its own Winston transport. Set OTEL_NODE_DISABLED_INSTRUMENTATIONS=winston for that process.
Pino transport not emitting: pino-opentelemetry-transport reads the OTEL_* env vars itself. Set them in the process that spawns the transport worker.
TLS errors against a self-signed endpoint: set NODE_EXTRA_CA_CERTS=/path/to/ca.pem.

Get Started

Send Logs

Traces

Search Logs

Manage Rootprint

Send logs from Node.js

Prerequisites

Setup

Structured logging

Framework recipe: Express

Troubleshooting

​Prerequisites

​Setup

​Structured logging

​Framework recipe: Express

​Troubleshooting

​Related

Prerequisites

Setup

Structured logging

Framework recipe: Express

Troubleshooting

Related