Send logs from Node.js

Rootprint accepts OpenTelemetry logs over OTLP HTTP. Node apps can use the plain OTEL SDK, or plug OTLP into Pino or Winston. All three routes ship records through the same endpoint and land in the OTEL logs index pinned by your ingest API key (otel-logs-v0_9 in these examples).

Prerequisites

A running Rootprint instance and its base URL — you’ll substitute it for <your-rootprint>.
Node.js 18+ with npm (the SDK needs native fetch and top-level await).
An ingest API key scoped to your target index. In Settings → API keys, click Create ingest key, give it a name, and pick the index (otel-logs-v0_9 for the examples here). See API keys.

Setup

Install

OTEL 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

Node.js 18+ is required (for native fetch and top-level await).

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-token>

The %20 after Bearer is required. OTEL expects URL-encoded header values.

Minimal working example

OTEL 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(new OTLPLogExporter())]
});

logs.setGlobalLoggerProvider(provider);

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

await provider.forceFlush();
await provider.shutdown(); // optional — flushes and stops the processor cleanly

import pino from 'pino';

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

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

// Short-lived scripts must wait for the worker transport to flush,
// otherwise the record never leaves the process.
await new Promise((resolve) => transport.on('close', resolve));
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(new OTLPLogExporter())]
});

logs.setGlobalLoggerProvider(provider);

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

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

// Short-lived scripts should shut down the provider before exit so the
// batch processor can flush buffered records.
await provider.shutdown();

Verify in Rootprint

Open Search, filter on service_name:my-node-service, and your record should appear within ~2 seconds.

Structured logging

Attributes become log-record attributes on the OTEL side: searchable and filterable 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

Initialise the SDK once at process start, then log from anywhere. Keep the setup in a separate module (e.g. otel.js) and import it before your Express app.

// otel.js
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';

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

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

logs.setGlobalLoggerProvider(provider);

export const logger = logs.getLogger('express-app');

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

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 / 403: the Bearer token is missing, malformed, or the %20 separator is not URL-encoded. Re-check OTEL_EXPORTER_OTLP_LOGS_HEADERS.
Nothing in Search: the batch processor buffers records. For short-lived scripts call await provider.forceFlush() (or await provider.shutdown()) before exit.
fetch is not defined: upgrade to Node.js 18+ or pass a polyfilled fetch to the exporter.
Pino transport not emitting: pino-opentelemetry-transport reads the OTEL_* env vars itself; make sure they are set in the process that spawns the transport worker.
TLS errors against a self-signed endpoint: set NODE_EXTRA_CA_CERTS=/path/to/ca.pem.

​Prerequisites

​Setup

​Structured logging

​Framework recipe: Express

​Troubleshooting

​Related

Prerequisites

Setup

Structured logging

Framework recipe: Express

Troubleshooting

Related