Upload image with RoR and Heroku - ruby-on-rails

Question

I recently deployed my ruby on rails app on Heroku and I am using the pg gem for my database.
I created a page where I can upload images and have them show on the main page and they are saved in a public folder within the app.
When I deployed it was working fine, but after sometime the images disappeared. When I looked at my Heroku logs I got the following:
ActionController::RoutingError (No route matches [GET] "/assets/products/6/photos/medium/shanab.jpg"):
I think the images are saved, but I don't know how to check if they are still there.

Answer 1

but after sometime the images disappeared
Heroku runs an ephemeral file system which means that each time you deploy a new version of your code, the old files/code are overwritten:
Each dyno gets its own ephemeral filesystem, with a fresh copy of the most recently deployed code. During the dyno’s lifetime its running processes can use the filesystem as a temporary scratchpad, but no files that are written are visible to processes in any other dyno and any files written will be discarded the moment the dyno is stopped or restarted.
This means that even if your images are working for a time, each new deploy will basically overwrite them. This is probably the cause of the problem, although I can't be sure without further inspection.
--
The way around this is to use a CDN, most common (although incorrect) is to tie your app with S3.
I don't know which asset-processing gem you're using, but if it's Paperclip, you'll want to use the inbuilt S3 functionality to put all your image assets onto Amazon's servers:
#app/models/x.rb
class x < ActiveRecord::Base
has_attached_file :download,
:storage => :s3,
:s3_credentials => Proc.new{|a| a.instance.s3_credentials }
def s3_credentials
{:bucket => "xxx", :access_key_id => "xxx", :secret_access_key => "xxx"}
end
end