upbeat/lib/upbeat/service.ms

Fast health and performance monitoring with process handling

var http = require('http');
var Action = require('./action');

export class Service {
  include $m.EventEmitter;

  function initialize(config) {
    this.name        = config.name;
    this.actionHash  = {};
    this.actions     = this.actionArray = [];

    this.up = true;

    for (var name in config.actions) {
      var aconfig  = config.actions[name];
      aconfig.name = aconfig.name || name;
      aconfig.service = this;
      this.addAction(new Action(aconfig));
    }

    this.actions = this.actions.sort(#{ => $1.name - $2.name });
  }

  function payload(period) {
    period = period || 'day';

    return this.actions.map(#(action) {
      return {
          name:     action.name,
          up:       action.isUp(),
          avgTime:  action.averageTime() + 'ms',
          uptime:   action.meta.uptime(),
          downtime: action.meta.downtime(),
          series:   action.meta.plotResponseTimes(period)
      }
    });
  }

  function isUp() {
    return this.up;
  }

  function addAction(action) {
    this.actions.push(action);
    this.actionHash[action.name] = action;

    var meta = action.meta;
    var evt = { service: this, action: action };

    action.on('fail', #{ self.emit('fail', evt); });
    action.on('pass', #{ self.emit('pass', evt); });

    action.on('down', #{
      var wasUp = self.up;
      self.up = false;
      self.emit('down', evt, $1);
      if (wasUp) self.emit('change', evt);
    });

    action.on('up', #{
      var changed = false;
      if (!self.up) {
        foreach (var a in self.actions) {
          if (! a.up) break;
        }

        self.up = true;
        changed = true;
      }

      self.emit('up', evt)
      if (changed) self.emit('change', evt);
    });
  }

  function handleConfig(config) {
    if (config.actions) {
      for (var k in config) {
        if (k == 'hosts' || k == 'actions') continue;
        foreach (var action in config.actions) {
          if (!(k in action)) action[k] = config[k];
        }
      }
    }
  }

  function getAction(name) {
    return this.actionHash[name];
  }

  function start() {
    foreach (var action in this.actions) {
      action.start();
    }
  }

  function stop() {
    foreach (var action in this.actions) {
      action.stop();
    }
  }

  function respondJSON(res) {
    var code = this.up ? 200 : 400;
    res.writeHead(code, {'Content-Type':'application/json'});
    res.write('[');

    foreach (var action:i in this.actions) {
      if (i!=0) res.write(',');
      res.write(action.toJSON());
    }

    res.end(']');
  }
}