koa-actuator

Healthcheck and monitoring middleware for koa inspired by java spring's actuators

Installation

$ npm install koa-actuator --save

Usage

const Koa = require('koa');
const actuator = require('koa-actuator');
const app = new Koa();
//...
app.use(actuator());
//...
app.listen(3000);

Ones you start your koa application, it will add endpoints /health, /info

Endpoints

The list of service endpoints and examples of responses is below:

/health

Performs health checks and returns the results:

{
  "status": "UP",
  "details: {
    "db": {
      "status": "UP",
      "details": {
        "freeConnections": 10
      }
    }
    "redis": {
      "status": "UP",
      "details": {
        "usedMemory": "52m",
        "uptimeDays": 16
      }
    }
  }
}

The statuses of the health checks are aggregated in a root-level status field. If at least one check yields DOWN status, the aggregated status will become DOWN. Health checks can be defined on actuator construction:

const healthChecks = {
 db: async () => {
   return {
     status: (await isDbAlive()) ? 'UP' : 'DOWN',
     freeConnections: await freeDbConnectionsLeft()
   }
 },
 //...
};
app.use(actuator(healthChecks));

A check can return an object of an arbitrary structure. If the returned structure contains status field, it will be counted in the aggregated status.

/info

Main application info from package.json

{
  "build": {
    "version": "1.0.0",
    "name": "koa-act-test",
    "main": "index.js",
    "description": "test"
  }
}

If git.properties file is present in application root directory, git section will also be available. In this case the response will look like:

{
  "build": {
    "version": "1.0.0",
    "name": "koa-act-test",
    "main": "index.js",
    "description": "test"
  },
  "git": {
    "commit": {
      "time": {
        "epochSecond": 1531473434,
        "nano": 0
      },
      "id": "a94ff08"
    },
    "branch": "origin/master"
  }
}