use hadoop hdfs in ruby

hdfs_client.rb

class HDFSClient
  attr_accessor :prefix_url
  def initialize(prefix_url)
    prefix_url.append("/") unless prefix_url.end_with?("/")
    @prefix_url = prefix_url  
  end

  def upload(file_name, file_path)
    system "curl -i -L -s -X PUT -T #{file_path} \
    #{@prefix_url}#{file_name}\\?op\\=CREATE"
    raise "😱 upload failed" unless $?.exitstatus == 0
  end

  def download(file_name)
    cmd = "curl \
    #{@prefix_url}#{file_name}\\?op\\=OPEN \
    --output #{file_name}"
    system cmd
    raise "😱 download failed" unless $?.exitstatus == 0
  end
end

# usage
# hdfs = HDFSClient.new("http://hadoop02.dev.rack.zhihu.com:50070/webhdfs/v1/user/ios/osee2binary/")
# hdfs.upload("upload.py", File.expand_path("upload.py", __dir__))
# system "rm -rf upload.py"
# hdfs.download("upload.py")