Presigned upload example in Ruby

presigned-test.rb

#!/usr/bin/env ruby

require "aws-sdk-s3"
require "net/http"

# Creates a presigned URL that can be used to upload content to an object.
#
# @param bucket [Aws::S3::Bucket] An existing Amazon S3 bucket.
# @param object_key [String] The key to give the uploaded object.
# @return [URI, nil] The parsed URI if successful; otherwise nil.
def get_presigned_url(bucket, object_key)
  url = bucket.object(object_key).presigned_url(:put)
  puts "Created presigned URL: #{url}"
  URI(url)
rescue Aws::Errors::ServiceError => e
  puts "Couldn't create presigned URL for #{bucket.name}:#{object_key}. Here's why: #{e.message}"
end

def run_demo
  bucket_name = "scs-presigned-upload-test"
  object_key = "my-file.txt"
  object_content = "This is the content of my-file.txt."

  bucket = Aws::S3::Bucket.new(bucket_name)
  presigned_url = get_presigned_url(bucket, object_key)
  return unless presigned_url

  response = Net::HTTP.start(presigned_url.host) do |http|
    http.send_request("PUT", presigned_url.request_uri, object_content, "content_type" => "")
  end

  case response
  when Net::HTTPSuccess
    puts "Content uploaded!"
  else
    puts response.value
  end
end

run_demo if $PROGRAM_NAME == __FILE__