images_controller.rb

=begin
There are better alternatives to storing images as a blob in the db like amazon s3, 
but I don't have a choice in this case

rails g model image file_name:string content_type:string file_size:integer file_data:binary
populate in the console
rails c
require 'net/http'
=> true
host = 'host_url'
path = 'path_to_photo'
res = Net::HTTP.get_response(host, path)
=> #<Net::HTTPOK 200 OK readbody=true>
Image.create!(file_name: 'something',
  content_type: res['Content-type'],
  file_size:    res.body.size,
  file_data:    res.body
)
=> #<Image id: 1, file_name: "something"...

config/routes.rb
match '/images/*file_name', controller: 'images', action: :show
=end

class ImagesController < ApplicationController
  caches_page :show
  
  def show
    if @image = Image.find_by_file_name(params[:file_name])
      send_data(@image.file_data, 
        type:        @image.content_type,
        filename:    @image.file_name,
        disposition: 'inline'
      )
    else
      render text: 'no soup for you'
    end
  end
end