Class: WebHDFS::Request

Inherits:
Object
  • Object
show all
Defined in:
lib/webhdfs/request.rb

Overview

Class to make http requests

Constant Summary collapse

KNOWN_ERRORS = 
['LeaseExpiredException'].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(host, port, options = {}) ⇒ Request

Constructor



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# File 'lib/webhdfs/request.rb', line 20

def initialize(host, port, options = {})
  @host = host
  @port = port
  @username = options[:username]
  @doas = options[:doas]
  @proxy = options[:proxy]
  @ssl = options[:ssl]
  @kerberos = options[:kerberos]
  @open_timeout = options[:open_timeout]
  @read_timeout = options[:read_timeout]
  @retry_known_errors = options[:retry_known_errors]
  @retry_times = options[:retry_times]
  @retry_interval = options[:retry_interval]
end

Instance Attribute Details

#doas ⇒ Object (readonly)

Returns the value of attribute doas.



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# File 'lib/webhdfs/request.rb', line 13

def doas
  @doas
end

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/webhdfs/request.rb', line 13

def host
  @host
end

#kerberos ⇒ Object (readonly)

Returns the value of attribute kerberos.



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# File 'lib/webhdfs/request.rb', line 14

def kerberos
  @kerberos
end

#open_timeout ⇒ Object (readonly)

Returns the value of attribute open_timeout.



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# File 'lib/webhdfs/request.rb', line 15

def open_timeout
  @open_timeout
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



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# File 'lib/webhdfs/request.rb', line 13

def port
  @port
end

#proxy ⇒ Object (readonly)

Returns the value of attribute proxy.



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# File 'lib/webhdfs/request.rb', line 14

def proxy
  @proxy
end

#read_timeout ⇒ Object (readonly)

Returns the value of attribute read_timeout.



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# File 'lib/webhdfs/request.rb', line 15

def read_timeout
  @read_timeout
end

#ssl ⇒ Object (readonly)

Returns the value of attribute ssl.



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# File 'lib/webhdfs/request.rb', line 14

def ssl
  @ssl
end

#username ⇒ Object (readonly)

Returns the value of attribute username.



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# File 'lib/webhdfs/request.rb', line 13

def username
  @username
end

Instance Method Details

#build_path(path, op, params) ⇒ Object 



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# File 'lib/webhdfs/request.rb', line 57

def build_path(path, op, params)
  path = Addressable::URI.escape(path)
  if op
    opts = if @username && @doas
             { 'op' => op, 'user.name' => @username, 'doas' => @doas }
           elsif @username
             { 'op' => op, 'user.name' => @username }
           elsif @doas
             { 'op' => op, 'doas' => @doas }
           else
             { 'op' => op }
           end
    WebHDFS.api_path(path) + '?' + URI.encode_www_form(params.merge(opts))
  else
    path
  end
end

#connection ⇒ Object 



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# File 'lib/webhdfs/request.rb', line 35

def connection
  conn = if @proxy
           Net::HTTP.new(host, port, @proxy.address, @proxy.port)
         else
           Net::HTTP.new(host, port)
         end

  if @proxy.authentication?
    conn.proxy_user = @proxy.user
    conn.proxy_pass = @proxy.password
  end

  conn.open_timeout = @open_timeout if @open_timeout
  conn.read_timeout = @read_timeout if @read_timeout

  if @ssl
    @ssl.apply_to(conn)
  else
    conn
  end
end

#execute(path, method, header = nil, payload = nil, op = nil, params = {}, retries = 0) ⇒ Object

Execute request



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# File 'lib/webhdfs/request.rb', line 131

def execute(path, method, header = nil, payload = nil, op = nil,
            params = {}, retries = 0)
  conn = connection

  header = @kerberos.autorization(header) if @kerberos

  request_path = build_path(path, op, params)

  response = make_request(conn, payload)

  @kerberos.check_response(response) if @kerberos

  case response
  when Net::HTTPSuccess
    response
  when Net::HTTPRedirection
    response
  else
    message = if response.body && !response.body.empty?
                response.body.delete("\n")
              else
                'Response body is empty...'
              end
    if @retry_known_errors && retries < @retry_times
      detail = nil
      if message =~ /^\{"RemoteException":\{/
        begin
          detail = JSON.parse(message)

          if detail['RemoteException'] &&
             KNOWN_ERRORS.include?(detail['RemoteException']['exception'])
            sleep @retry_interval if @retry_interval > 0
            return execute(path, method, header, payload, op, params,
                           retries + 1)
          end
        rescue
          # ignore broken json response body
        end
      end
    end
    raise_response_error(response.code, message)
  end
end

#generic_request(connection, request_path, method, header = nil, payload = nil) ⇒ Object

Raises:



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# File 'lib/webhdfs/request.rb', line 75

def generic_request(connection, request_path, method, header = nil,
                    payload = nil)
  res = nil
  req = Net::HTTPGenericRequest.new(method, (payload ? true : false),
                                    true, request_path, header)
  raise WebHDFS::ClientError, 'Error accepting given IO resource as' \
   ' data payload, Not valid in methods' \
   ' other than PUT and POST' unless method == 'PUT' || method == 'POST'

  req.body_stream = payload
  req.content_length = payload.size
  begin
    res = connection.request(req)
  rescue => e
    raise WebHDFS::ServerError, 'Failed to connect to host' \
                                " #{@host}:#{@port}, #{e.message}"
  end
  res
end

#make_request(connection, request_path, method, header = nil, payload = nil) ⇒ Object 



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# File 'lib/webhdfs/request.rb', line 95

def make_request(connection, request_path, method, header = nil,
                 payload = nil)
  res = nil
  if !payload.nil? && payload.respond_to?(:read) &&
     payload.respond_to?(:size)
    res = generic_request(connection, request_path, method, header, payload)
  else
    begin
      res = connection.send_request(method, request_path, payload, header)
    rescue => e
      raise WebHDFS::ServerError, 'Failed to connect to host' \
                                  " #{@host}:#{@port}, #{e.message}"
    end
  end
  res
end

#raise_response_error(code, message) ⇒ Object 



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# File 'lib/webhdfs/request.rb', line 112

def raise_response_error(code, message)
  case code
  when '400'
    raise WebHDFS::ClientError, message
  when '401'
    raise WebHDFS::SecurityError, message
  when '403'
    raise WebHDFS::IOError, message
  when '404'
    raise WebHDFS::FileNotFoundError, message
  when '500'
    raise WebHDFS::ServerError, message
  else
    raise WebHDFS::RequestFailedError, "response code:#{code}, " \
                                       "message:#{message}"
  end
end