micro-health

micro-health is used as an extension for micro to add the route /health to your service. It was meant to implement the Health Check API microservice design pattern for microservices monitoring. For long read I suggest reading this page.

Usage

cd my-micro-project/
npm install --save micro-health

and add use the package like this:

// index.js
const health = require('micro-health')

const microFn = () => 'Hello World'
module.exports = health(microFn)

then just run your microservice normally and it will expose a /health endpoint.

By default the health request it will return you an HTTP 200 response with a 'success' message and it will fail if the microservice isn't available, this guarantees that your microservice is working or not regardless of the other functions of microservice itself. Also it supports a custom errorChecker:

// index.js
const health = require('micro-health')

const microFn = (req, res) => {
  // Wonderful code
}

const errorChecker = () => {
  // Check if database pool connection is full
  // Check if there is still space on filesystem
  // Check if external APIs are working
  try {
    await customChecking()
   catch (e) {
     return { error: e }
   }
  // You can also return false to pass the health checking
}

module.exports = health(microFn, errorChecker)

If error aren't falsy the health request will return an HTTP 500 response with the returned object by the error checker.

There are several tools for health checking such us:

• Microservice Graph Explorer
• nginx
• CoScale

Or... you can just build your own!

Contributing

1. Fork this repository to your own GitHub account and then clone it to your local device
2. Link the package to the global module directory: npm link
3. Within the module you want to test your local development instance of micro-cacheable, just link it to the dependencies: npm link micro-health. Instead of the default one from npm, node will now use your clone of micro-health!

Credits

Thanks to ZEIT Team for giving us micro to make our life easier!