paramedic

Paramedic

A simple health monitor server for running health checks periodically.

Installation

npm install paramedic

Usage

Step 1: Create a new server.

var medic = require('paramedic').createServer()

Step 2: Load up your tests. There are two callbacks passed to each test: done and warn. If you pass an error (or string) as the first argument to either of these callbacks, the test will fail: done emits an error, whereas warn only emits a warning.

var request = require('request')

medic.test('Google Australia', function(done, warn) {
    request.get('http://google.com.au/', function(err) {
        return done(err);
    });
}).interval(6000);

medic.test('Google UK', function(done, warn) {
    request.get('http://google.co.uk/', function(err) {
        return warn(err);
    });
}).interval(21000);

Step 3: Start up the server! start() returns a request callback for you to easily plug into an HTTP server, or as an Express route.

var http = require('http')
  , server = medic.start();

http.createServer(server).listen(8080);

After that, your server should be running on port 8080, similar to this:

Collections

You can create "collections" of tests too. These function as reusable templates, which can then be loaded using the collection's add method.

medic.collection('Google Queries', function(data) {
    this.test('http://google.com/?q=' + data.query, function(done, warn) {
        request.get(data.url, done);
    }).interval(data.interval);
}).add({
      query: 'lorem'
    , interval:  6000
}).add({
      query: 'lorem'
    , interval: 21000
});

Events

The server page will update accordingly as tests fail and recover, but the server also emits error, warn, pass and recover events.

This can be used, for example, to send notifications or automate a recovery.

ready is emitted when the server has started testing.