error: undefined method `presigned_post' - ruby-on-rails

Question

I'm writing a rails application with which a user can upload images. I am deploying with Heroku, and using Carrierwave and S3 to upload and store images. I have followed this heroku guide step-by-step...unfortunately I am still getting an error "undefined method `presigned_post'", and do not know how to resolve it. It seems the S3_BUCKET is not being recognized as an aws object...
Has anyone come across this problem and figured it out? Here's some code for reference:
Pictures controller:
class PicturesController < ApplicationController
before_action :set_s3_direct_post, only: [:new, :create]
def index
#pictures = Picture.all
end
def new
#pictures = Picture.all
#picture = Picture.new
end
def create
#picture = Picture.new(picture_params)
if #picture.save
redirect_to new_picture_path, notice: "You just uploaded a picture!"
else
render "new"
end
end
...
def picture_params
params.require(:picture).permit(:attachment)
end
private
def set_s3_direct_post
#s3_direct_post = S3_BUCKET.presigned_post(key: "uploads/#{SecureRandom.uuid}/${filename}", success_action_status: '201', acl: 'public-read')
end
end
New picture view:
<h1>Upload a new picture</h1>
<br>
<div class="well">
<%= form_for #picture, html: { class: 'directUpload', data: { 'form-data' => (#s3_direct_post.fields), 'url' => #s3_direct_post.url, 'host' => URI.parse(#s3_direct_post.url).host } } do |f| %>
<%= f.file_field :attachment %>
<%= f.submit "Upload", class: "btn btn-default" %>
<% end %>
</div>
And config/environment.rb:
require File.expand_path('../application', __FILE__)
# Initialize the Rails application.
Rails.application.initialize!
# S3
S3_BUCKET='fotoes'
AWS_ACCESS_KEY_ID='secretxxxxxxxx'
AWS_SECRET_ACCESS_KEY='xxxxxxxsecretxxxxxx'
Any thoughts?

Answer 1

#Jillian I suppose your expectation was that S3_BUCKET class should call presigned_post method which is supposed to be defined. However, it seems its not. I took a look at the heroku page containing the tutorial you followed and well you followed every instruction. I suggest you contact heroku about the documentation. However, I would keep looking into it

Answer 2

Thank you all for your help. In the end I found a different walk-through that was much simpler and effective. (The Heroku one was a little complicated and left a lot to go wrong - go figure.)
This solved everything :)
edit:
not everything - had to complete one last step before I got the site running. Run this line in the terminal: $ heroku config:add AWS_ACCESS_KEY=value
and $ heroku config:add AWS_SECRET_KEY=value, where the value is your S3 credentials for each, respectively.
This was the only combo of fog, carrierwave, rails, fog-aws gems that worked (after weeks of fussing with them):
gem 'rails', '4.1.0'
gem 'carrierwave', '~> 0.10.0'
gem 'fog', '1.34.0'
gem 'fog-aws', '0.7.6'

Answer 3

i resolved this by updating my version of aws-sdk
$ bundle update aws-sdk