Send events to Last9 from Node.js apps

This project demonstrates how to send JSON events to Last9 using the OpenTelemetry OTLP HTTP exporter. The application runs in a continuous loop, sending events until interrupted by Ctrl-C.

Setup

Requires Node.js 24.22.1 or a later 24.x release (.nvmrc pins 24.22.1). Earlier releases accept certificate chains from the distrusted eMudhra CA.

1. Install dependencies:

npm install

2. Set up environment variables:

cp .env.example .env
# Edit .env with your Last9 credentials and endpoint

Environment Variables

Required Variables

• LAST9_ENDPOINT: Your Last9 OTLP endpoint (without /v1/logs suffix)
• LAST9_USER: Last9 Username for basic auth
• LAST9_PASSWORD: Last9 Password for basic auth

Optional Variables

• SERVICE_NAME: Service name for telemetry (defaults to 'default-service')
• EVENT_INTERVAL_MS: Time interval between events in milliseconds (defaults to 1000ms)
• MAX_EVENTS: Maximum number of events to send before stopping (defaults to unlimited, use -1 for unlimited)

Running the Example

Local Development

Basic usage (sends events every 1 second until Ctrl-C):

node last9-events-emitter.js

Custom interval (sends events every 500ms):

EVENT_INTERVAL_MS=500 node last9-events-emitter.js

Limited events (sends only 50 events):

MAX_EVENTS=50 node last9-events-emitter.js

Combined settings:

EVENT_INTERVAL_MS=2000 MAX_EVENTS=100 node last9-events-emitter.js

Using Docker

# Build the Docker image
docker build -t last9-events-dispatcher .

# Run with environment variables
docker run --env-file .env last9-events-dispatcher

# Or run with inline environment variables
docker run -e LAST9_ENDPOINT=your_last9_endpoint \
           -e LAST9_USER=your_user \
           -e LAST9_PASSWORD=your_password \
           -e SERVICE_NAME=events-nodejs-service \
           -e EVENT_INTERVAL_MS=2000 \
           -e MAX_EVENTS=100 \
           last9-events-dispatcher

Checking the TLS blocklist

npm run check:tls confirms the runtime rejects the eMudhra test chain with CERT_REVOKED and still reaches a trusted HTTPS endpoint. It needs network access; behind a proxy, run node --use-env-proxy scripts/check-tls-blocklist.js.

Stopping the Application

• Press Ctrl-C to gracefully stop the application
• The application will ensure all pending events are sent before shutting down
• If MAX_EVENTS is set, the application will automatically stop after reaching the limit

Example Output

Starting event emitter loop...
Event interval: 1000ms
Max events: unlimited
Press Ctrl-C to stop

Event 1 sent at 2024-01-15T10:30:00.000Z
Event 2 sent at 2024-01-15T10:30:01.000Z
...
Event 10 sent at 2024-01-15T10:30:09.000Z
Error event 10 sent at 2024-01-15T10:30:09.000Z
...

Received SIGINT. Shutting down gracefully...
Shutdown complete.

You can create powerful log analytics dashboards using these events into Last9. The events are added in physical index named events in Last9.

https://www.loom.com/share/2767f6fa3ff9460c8374558f7ac3debe