mariozig

#Heroku, Ruby on Rails and PhantomJS

In this post, I’m going to show you how to modify an existing Ruby on Rails app running on Heroku’s Cedar stack to use PhantomJS for screen scraping. If you’ve never heard of PhantomJS, it’s a command-line WebKit-based browser (that supports JavaScript, cookies, etc.).

Let’s get started. This is a high-level overview of the required steps:

• Modify your app to use multiple Heroku buildpacks.
• Extend your app to use both the Ruby as well as the PhantomJS buildpacks.
• Confirm that everything worked.

mariozig

$ docker images
REPOSITORY           TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
bloggy_web           latest              fd72d1901622        10 hours ago        912 MB
<none>               <none>              a51a0506164a        10 hours ago        903.4 MB
bloggy_square        latest              4246ada965f2        10 hours ago        903.4 MB
<none>               <none>              6e1e68d610ba        10 hours ago        903.4 MB
docker_square        latest              85c7ac711d78        11 hours ago        808.9 MB
postgres             9.4.1               03119fe33f25        4 days ago          213.9 MB
ruby                 2.2.1               ef6e4b7dc7cd        3 weeks ago         775.1 MB
kirkdockerized_web   latest              83edc1a1d29a        4 months ago        347.8 MB

mariozig

## Issue:
NameError in Admin/tweetsController#index

undefined local variable or method `tweets' for #<Class:0x7fcbe98f68f0>
Rails.root: /home/rails/

Application Trace | Framework Trace | Full Trace
app/models/tweet.rb:23:in `add_tweets'
app/models/tweet.rb:15:in `update_twitter_account'
app/models/tweet.rb:9:in `update_tweets'

mariozig

io@love:~/rails/m3$ git branch -a
  admin
  authlogic
  inlineadmin
  list
* master
  remotes/origin/add_devise
  remotes/origin/admin
  remotes/origin/authlogic
  remotes/origin/master

mariozig

Padrino.after_load do
  require 'will_paginate/view_helpers/base'
  require 'will_paginate/view_helpers/link_renderer'
  require 'will_paginate/finders/active_record'
  WillPaginate::Finders::ActiveRecord.enable!
end

mariozig

array_of_hashes = ModelOneAddress.all + ModelTwoAddress.all
array_of_hashes.sort_by { |hsh| hsh[:zip] }

mariozig

## The setup
# This assumes you already have friendly_id in your gemfile and all that good stuff.
class Car < ActiveRecord::Base
  # Slugs via FriendlyId
  extend FriendlyId
  friendly_id :name, :use => :scoped, :scope => :type
end

class Ford < Car
end

mariozig

mario@red demo $ git clone https://github.com/maxlapshin/mysql2postgres.git
Cloning into mysql2postgres...
cd myremote: Counting objects: 516, done.
remote: Compressing objects: 100% (269/269), done.
remote: Total 516 (delta 262), reused 486 (delta 237)
Receiving objects: 100% (516/516), 84.68 KiB, done.
Resolving deltas: 100% (262/262), done.
mario@red demo $ cd mysql2postgres/
# Optional: I use RVM and wanted to use ruby 1.9.2
mario@red mysql2postgres $ rvm ruby-1.9.2-p290

mariozig

# No Config File
mario@red mysql2postgres $ ls -la | grep yml
mario@red mysql2postgres $ mysql2psql
/Users/mario/.rvm/gems/ruby-1.9.2-p290/gems/mysql2psql-0.1.0/lib/mysql2psql/config.rb:14:in `initialize':  (Mysql2psql::ConfigurationFileInitialized)

No configuration file found.
A new file has been initialized at: /Users/mario/ruby/demo/mysql2postgres/mysql2psql.yml
Please review the configuration and retry..

# Aw yeah, there she is

mariozig

mario@red mysql2postgres $ mysql2psql
Table creation 0 min, loading 7 min, indexing 0 min, total 7 min