I have customer files uploaded to Amazon S3, and I would like to add a feature to count the size of those files for each customer. Is there a way to "peek" into the file size without downloading them? I know you can view from the Amazon control panel but I need to do it pro grammatically.
Send an HTTP HEAD request to the object. A HEAD request will retrieve the same HTTP headers as a GET request, but it will not retrieve the body of the object (saving you bandwidth). You can then parse out the Content-Length header value from the HTTP response headers.
Using Michael's advice, my successful code looked like this:
require 'net/http'
require 'uri'
file_url = MyObject.first.file.url
url = URI.parse(file_url)
req = Net::HTTP::Head.new url.path
res = Net::HTTP.start(url.host, url.port) {|http|
http.request(req)
}
file_length = res["content-length"]