ruby - AWS to serve CSS images Sinatra -

I am using the asset_sync gem to sync my assets in S3 bucket. I want to use and use my local files in development. So I have set up the following with a helper:

Configure the environment / development.rb

 : The development is set: asset_host, "/" end  < / Pre> 
 Environment / Production .rb  
  Configure: The output is set: asset_host, "https://s3-eu-west-1.amazonaws.com/# {ENV [FOG_DIRECTORY ']} "End << / code>  
 ASSISTANT  
  Aadhaar DAF can file aws_asset (path) .Join settings.set_host, path expiration < / Code>  
 So in my thoughts I can do this  
    
 As a result, it will result in the development of my local assets or when I am in production with my bucket  
 What if I want to render an image from inside My main cas file, such as background image? I can not do this for example because it is not an ARB file  
 main.css  
  header {background: #ffffff url (';) Repeat-X; }   
 So what can I do?   
 
 
 Thanks for any help from 3 ways  
  
 Precompile Assets  
 Before deploying, precompile assets and css if you create a file called  main.css.erb  and then If you run to create  main.css  through the ERB, then it will have the right content. It will be my priority. Precompile has many ways, I like but YMMV  
 
 Edit:  
  
  Guard 'lift and twist from erb',: input = & gt; 'App / Scene / Stylesheet / Main Cass. ARB ',: Output = & gt;   
 Something like this "Public / property / stylesheet / main case" clock (% r {app / views / stylesheets / main.css.erb})  
 
 Create a route while compiling that property  
 This is similar to the way you use the SASS template with Sinatra (if you do not precompile them) just do it as above, set a path for  main.css  Run and run the  main.css.erb  template through ERB. Add a lot.  
 
 Edit:  
 Get code for "/assets/stylesheets/main.css" #caching Remember: erg "stylesheet / main. Css "end   
 
 I started writing and I can not remember 3. In my defense, I have a terrible headache, maybe someone else will remember me for me.