Get the health status without using a HTTP request

[BrunnerLivio]

Issue

I would like to read out the current health status, without having to create a HTTP request.
Therefore the health status should be readable programmatically using the public Terminus API.

Something like this:

const { getHealthStatus } = require('@godaddy/terminus');

// Returns { status: 'ok' | 'error', info: {...} }
getHealthStatus('/health');

Implementation

Looking through your code, I realized the core (terminus.js) would have to get restructured if done correctly.

When I tried to refactor the method decorateWithHealthCheck in terminus.js which contains the desired functionality, I realized everything is handled over parameters. My refactored function would look like the following:

function getHealthStatus(url, state, options) {
  const { healthChecks, logger } = options;
  if (state.isShuttingDown) {
    return sendFailure(res)
  }
  healthChecks[url]()
    .then((info) => {
      sendSuccess(res, info)
    })
    .catch((error) => {
      logger('healthcheck failed', error)
      sendFailure(res, error.causes)
    })
}

The problem is, a user should not pass state nor options as a parameter. Thus it is still required for the functionality of getHealthStatus. A way to solve this problem, is to use a class instance for each createTerminus() call, which then can handle state or options as a property.

[gergelyke]

Hi @BrunnerLivio - any chance you can work on a PR to address this? If not, I can take it on sometimes next week.

[BrunnerLivio]

I also do not know if I have time for this either, but try to look into it.

I think I have to break the public API (again 😅 ) in order to achieve this.

[gergelyke]

No worries - that's why we have semver :)

[gergelyke]

Closing this as per #87