Website at https://docs.aws.amazon.com/sdk-for-ruby.

Installation:

$ gem install aws-sdk-s3

Create a file named `list.rb` with the following contents (substituting `mybucket`, `<your access key>`. `<your secret>` with your information):

require 'aws-sdk-s3' # v2: require 'aws-sdk'

s3 = Aws::S3::Client.new(
  endpoint: "https://polycloud.crowdapis.com",
  access_key_id: "<your access key>",
  secret_access_key: "<your secret>",
  region: 'us-east-1'
)

resp = s3.list_objects(bucket: 'mybucket')
resp.contents.each do |object|
  puts "#{object.key}"
end

Run the example:

$ ruby list.rb