Rails : Carrierwave + S3 + Heroku with ENV variables

setup_carrierwave.sh

#!/bin/bash
# Use as follows :
# ./setup_carrierwave.sh local
# ./setup_carrierwave.sh remote project_name [production/staging]

set -e

# Parameters
MODE=$1
PROJECT_NAME=$2
REMOTE=$3

if [ "$MODE" = "local" ] ;then
  # Add Carrierwave to Gemfile
  echo "# Carrierwave for file uploads
gem 'fog'
gem 'fog-aws'
gem 'carrierwave'
gem 'mini_magick'" >> Gemfile
  
  # Install Carrierwave
  bundle install
  
  echo "CarrierWave.configure do |config|
  config.fog_credentials = {
    :provider               => 'AWS',
    :aws_access_key_id      => ENV['AWS_ACCESS_KEY']        || '',
    :aws_secret_access_key  => ENV['AWS_SECRET_ACCESS_KEY'] || '',
    :region                 => ENV['AWS_REGION']            || '',
    :path_style             => true
  }

  config.fog_directory    = ENV['AWS_S3_BUCKET']            || ''
  config.fog_public       = true
  config.fog_attributes   = {'Cache-Control'=>'max-age=86400'}

  if Rails.env.production?
    config.asset_host       = 'http://#{config.fog_directory}.s3.amazonaws.com'
  end
end" > config/initializers/carrierwave.rb

  echo "Done ! Carrierwave is now installed locally."
  
elif [ "$MODE" = "remote" ] ;then
  if [ -z "$PROJECT_NAME" ] ;then
    echo "Missing parameter : project-name"
    exit 1
  fi
  if [ -z "$REMOTE" ] ;then
    echo "Missing parameter : remote"
    exit 1
  fi
  echo "Creating AWS user"
  aws iam create-user --user-name $PROJECT_NAME
  echo "Creating AWS bucket"
  aws s3 mb s3://$PROJECT_NAME
  echo "{
  \"Version\": \"2012-10-17\",
  \"Statement\": [
      {
          \"Action\": \"s3:*\",
          \"Effect\": \"Allow\",
          \"Resource\": [
              \"arn:aws:s3:::$PROJECT_NAME/*\"
          ]
      }
  ]
}" > $PROJECT_NAME.json
  echo "Attaching user policy"
  aws iam put-user-policy --user-name $PROJECT_NAME --policy-name $PROJECT_NAME --policy-document file://$PROJECT_NAME.json
  rm $PROJECT_NAME.json

  echo "Creating access key"
  access="$(aws iam create-access-key --user-name $PROJECT_NAME --output text)"
  arr=($line)

  AWS_ACCESS_KEY=${arr[1]}
  AWS_SECRET_ACCESS_KEY=${arr[3]}  

  heroku config:set AWS_ACCESS_KEY=$AWS_ACCESS_KEY -r $REMOTE
  heroku config:set AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY -r $REMOTE
  heroku config:set AWS_REGION=us-east-1 -r $REMOTE
  heroku config:set AWS_S3_BUCKET=$PROJECT_NAME -r $REMOTE

else
  echo "Missing parameter : mode"
  exit 1
fi