Digipolis Probes

This package includes a livenessprobe and a readinessprobe.

• A livenessprobe checks if the app is still active. If it's not, the pod/container will be restarterd.
• A readinessprobe checks if the app is ready to process requests. If the readinessprobe fails, no requests will be sent to this pod/container.

This package exposes two endpoints:

• /status/alive for the livenessprobe.
• /status/ready for the readinessprobe.

After including this package in your project you'll need to configure it in appconfig. Here is a small how-to.

Installation

npm i @digipolis/probes

Configuration

This package will work without any configuration but it is best practice to add some.

| Param | Description | | ------------------------- | -------------------------------- | | alive (optional) | Array with alive check functions | | ready (optional) | Array with ready check functions |

Example

const probes = require('@digipolis/probes');

function customReadyCheck() {
  const ready = true;

  return new Promise((resolve, reject) => {
    if(!ready) {
      return reject({status: 400, message: 'Uh oh! This app is not ready.'});
    }

    return resolve();
  })
}

const config = {
  hooks: {
    ready: [
      customReadyCheck
    ]
  }
};

app.use(probes(config));

Error object

When there's an error (app is not alive/ready) you'll reject with an object.

| Key | Value | | ------------------------- | -------------------------------- | | status (number) | The status code you want to respond with. Should not be 200. | | message (string | A human readable message that will appear in the logs and your browser |

If you omit a status a 500 will be used.

Example

  return reject({status: 400, message: 'Uh oh! This app is not ready.'});

If your app is in good shape and ready to handle traffic you resolve the promise. return resolve();

Tests

run npm t

Authors

See the list of contributors who participated in this project.