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jpbalarini /
Last active Aug 29, 2015
Setting up email with Sendgrid

Generate the user mailer class

rails generate mailer UserMailer

Define the method for sending emails

class UserMailer < ActionMailer::Base
  include SendGrid
  sendgrid_category :use_subject_lines
View image_file_whitelist.rb
{ name: 'png', first_bytes: '89 50 4E 47 0D 0A 1A 0A' },
{ name: 'jpg1', first_bytes: 'FF D8 FF DB' },
{ name: 'jpg2', first_bytes: 'FF D8 FF E0' },
{ name: 'jpg3', first_bytes: 'FF D8 FF E1' },
{ name: 'ico', first_bytes: '00 00 01 00' },
{ name: 'gif1', first_bytes: '47 49 46 38 37 61' },
{ name: 'gif2', first_bytes: '47 49 46 38 39 61' },
{ name: 'tiff1', first_bytes: '49 49 2A 00' },
{ name: 'tiff2', first_bytes: '4D 4D 00 2A' },
jpbalarini /
Last active Feb 15, 2017
How to create a RoR Bitnami Amazon EC2 instance

RoR Bitnami Amazon EC2 instance

This guide will provide you some basic steps to create a Bitnami RoR Amazon EC2 instance, using Nginx with Passenger.

  1. Create an Amazon EC2 instance using a Community AMI. At the time of writing, the latest Bitnami AMI is: bitnami-rubystack-2.2.4-4-linux-ubuntu-14.04.1-x86_64-hvm-ebs Be careful to open SSH, HTTP and HTTPS ports on the "Step 6: Configure Security Group". You will need to save also the certificate to later connect to the instance.

  2. Log in by SSH to the instance:

jpbalarini / downloader_server.js
Created Jan 22, 2019
Pupeteer downloder server
View downloader_server.js
const puppeteer = require('puppeteer')
const express = require('express')
const bodyParser = require('body-parser')
const crypto = require('crypto')
const fs = require('fs')
const port = 3000
var app = express()
jpbalarini /
Last active Jan 22, 2019
Batch check URL status code
# usage: sh URLs.txt
# example output: 200
# It saves all output to url_statuses.txt
if [ -z "$FILENAME" ]; then
echo "Usage: URLs.txt"
jpbalarini /
Last active Feb 8, 2019
Mac OS Sierra Rails development

How to configure your Mac OS for Ruby on Rails development

  1. Install Sublime Text from here
  2. Install Xcode from the AppStore
  3. Open Xcode and accept the licence
  4. Install command line tools. From the terminal run:
    xcode-select --install
  5. Install homebrew
jpbalarini / action_cable_send_backend.js
Created Jun 19, 2019
How to execute a method on rails via action cable
View action_cable_send_backend.js
socket = new WebSocket('ws://localhost:3000/api/v1/action_cable');
const onMessage = (ws, store) => evt => {
let msg = JSON.parse(;
if (msg.type === "ping") {
console.log("FROM RAILS: ", msg);
socket.onmessage = onMessage(socket);
jpbalarini / application_controller.rb
Last active Oct 31, 2019
Ruby on Rails CORS Preflight Check
View application_controller.rb
before_action :cors_set_access_control_headers
def cors_preflight_check
if request.method == 'OPTIONS'
render text: '', content_type: 'text/plain'
You can’t perform that action at this time.