running background job on a specific action in sails js

Question

i am trying to make a service that runs in background when specific event happens. As an example when user verifies email i want my service of deleting possible unverified duplicate emails form database. i tried using kue to save my purpose but i think its more like the services will run once the sails lift fires?

so how to run a service when specific event happens? any help would be much appreciated.

thanks

Answer 1

You can indeed use Kue for this purpose.

1. Create a config file kue.js for Kue

   var kue = require('kue');
   var kue_engine = kue.createQueue({
     prefix: 'kue',
     redis: {
       port: '6379',
       host: 'localhost'
     }
   });
   
   
   process.once('SIGTERM', function (sig) {
     kue_engine.shutdown( 5000, function(err) {
       console.log( 'Kue shutdown: ', err||'' );
       process.exit( 0 );
     });
   });
   
   module.exports.kue = kue_engine;
   

2. Add the job to Kue in relevant controller action.

   var kue_engine = sails.config.kue;
   kue_engine.create('delete_verified_email', {email: '123@456.com'})
     .priority('medium')
     .attempts(3)
     .save();
   

3. Create a worker.js in project root to consume kue jobs.

   var kue = require('kue');
   require('sails').load({
       hooks: {
           blueprints: false,
           cors: false,
           csrf: false,
           grunt: false,
           http: false,
           i18n: false,
           logger: false,
           policies: false,
           pubsub: false,
           request: false,
           responses: false,
           session: false,
           sockets: false,
           views: false
         }
       }, function (err, app) {
             sails.log.info('Starting kue');
             var kue_engine = sails.config.kue;
   
             //register kue.
   
             kue_engine.on('job complete', function (id) {
                 sails.log.info('Removing completed job: ' + id);
                 kue.Job.get(id, function (err, job) {
                     job.remove();
                 });
             });
             kue_engine.process('delete_verified_email', 20, function (job, done) {
                 // you can access the data passed while creating job at job.data
                 // all the sails models, services are available here
                 console.log(job.data.email)
                 done && done();
             });
   

4. Run the worker.js to consume the kue jobs created by your sails app.

Answer 2

Maybe Sails.js lifecycle hooks could help you. We are using them for instance to update statistics, e.g. persisting number of users per type after a user update call.

Also we are using Node Agenda (Sails.js hook) to create jobs to be executed either one time to a defined time in the future or like a cron job. Maybe you will want to collect the invalid/ expired email address verification entries to be purged and delete them in a hourly batch.