Sematext Agent Express

This is the Express.js monitoring and logging agent for Sematext. The following data is collected and shipped to Sematext Cloud / Enterprise:

• OS Metrics (CPU / Mem)
• Process Memory
• Process Metrics
• EventLoop Metrics
• Garbage Collector Metrics
• Web Server Metrics:
  • request rate
  • error rate
  • response times
  • content size
• HTTP Logs per API endpoint:
  • response times
  • content size
  • URL
  • status
  • method
• Custom Logs:
  • Instead of using console.log ship all logs directly to Sematext Logs with stLogger

Quickstart

1. Sign up to Sematext for free
2. Create a Node.js Monitoring App and copy the Monitoring App Token
3. Create a Logs App and copy the Logs App Token
4. Install the sematext-agent-express npm module
5. Configure environment variables
6. Run the agent using the App tokens provided for your Monitoring and Logs Apps

Create Apps in Sematext

After you sign up to Sematext here, you need to create Apps to store metrics and logs data.

1. Create a Logs App
2. Create a Monitoring App

Installation

Install the package from the NPM registry.

npm i sematext-agent-express

Configure Environment

Make sure to configure your ENVIRONMENT variables before adding sematext-agent-express. You can do this either by exporting the variables to your environment or by using dotenv. We suggest you use dotenv.

Export env vars

If you are using the US region of Sematext Cloud:

export MONITORING_TOKEN=<YOUR_MONITORING_TOKEN>
export LOGS_TOKEN=<YOUR_LOGS_TOKEN>
export INFRA_TOKEN=<YOUR_INFRA_TOKEN>

If you are using the EU region of Sematext Cloud:

export REGION=EU
export MONITORING_TOKEN=<YOUR_MONITORING_TOKEN>
export LOGS_TOKEN=<YOUR_LOGS_TOKEN>
export INFRA_TOKEN=<YOUR_INFRA_TOKEN>

Use dotenv

npm i dotenv

Create a .env file in the root of your project.

Add this code if you are using the US region of Sematext Cloud:

MONITORING_TOKEN=<YOUR_MONITORING_TOKEN>
LOGS_TOKEN=<YOUR_LOGS_TOKEN>
INFRA_TOKEN=<YOUR_INFRA_TOKEN>

Add this code if you are using the EU region of Sematext Cloud:

REGION=EU
MONITORING_TOKEN=<YOUR_MONITORING_TOKEN>
LOGS_TOKEN=<YOUR_LOGS_TOKEN>
INFRA_TOKEN=<YOUR_INFRA_TOKEN>

Configure Agent

Make sure to load the environment variables at the top of your JavaScript entry point file. Then require sematext-agent-express.

The Agent has 3 parts:

• stMonitor - Monitors metrics and sends to Sematext Monitoring
• stLogger - A logger based on winston, that will send logs directly to Sematext Logs
• stHttpLoggerMiddleware - Express.js middleware function that will send all HTTP endpoint logs to Sematext Logs

Usage

// Load env vars
require('dotenv').config()

// require all agents
const { stMonitor, stLogger, stHttpLoggerMiddleware } = require('sematext-agent-express')

// Start monitoring metrics
stMonitor.start()

// ...

// At the top of your routes add the stHttpLoggerMiddleware to send HTTP logs to Sematext
const express = require('express')
const app = express()
app.use(stHttpLoggerMiddleware)

// ...

// Use the stLogger to send all types of logs directly to Sematext
app.get('/api', (req, res, next) => {
  stLogger.info('Hello World.')
  stLogger.error('Some error.')
  res.status(200).send('Hello World.')
})

You can use all parts of the Agent of use them separately. It's all up to you.

Result

The Agents will capture both metrics, logs, and HTTP logs per API endpoint.

Metrics

Logs

Troubleshooting

Check out our documentation for more information.

Built with

• spm-agent-nodejs
• winston
• winston-logsene
• morgan
• morgan-json

LICENSE

Apache 2 - see the LICENSE file.