standard-healthcheck

This tiny library exposes a health check endpoint in a standard response format per Internet Engineering Task Force (IETF). The proposed standard includes a few properties not included in standard extensions:

• description
• version number (important for debugging)
• uptime
• details about dependent downstream services

Example Output

Example JSON response from https://nodejs-demo.onazure.io/health

{
  "status": "pass",
  "description": "A multipurpose dummy node.js app for cloud architecture demos",
  "version": "0.2.1",
  "details": {
    "uptime": {
      "component_type": "system",
      "observed_value": 74401.282209224,
      "human_readable": "0 days, 20 hours, 40 minutes, 1 seconds",
      "observed_unit": "s",
      "status": "pass",
      "time": "2020-02-20T13:05:11.307Z"
    },
    "env": {
      "WEBSITE_HOSTNAME": "azure-nodejs-demo.azurewebsites.net",
      "WEBSITE_INSTANCE_ID": "c33cdebf5b0f427fdd331f28322f183c95c5320c0c952d9194ad7ce9867c2eaa"
    }
  }
}

For details about schema, see IETF draft document.

Usage

npm install --save standard-healthcheck

Then import the library in your Express.js application and add the route to your app:

const healthcheck = require('standard-healthcheck')
app.get('/health', healthcheck({
    version: '1.0',
    description: 'My demo app',
    includeEnv: ['NODE_ENV']
})

Optional: Environment variables

The proposed standard because is friendly for debugging. You can ask standard-healthcheck to output some environment variables (not recommended for production!) via the includeEnv optional property.

But it will ignore variables ending with SECRET, PASSWORD, _KEY and _PASS for security reasons.