TCP Socket programming in Ruby

As software developers, a lot of the time we’re building applications that rely on some sort of network connection. Due to Ruby’s great abstractions we take most of the network related stuff for granted. We think we know how all of that works, but do we? Let’s go over the fundamentals together, learn about how Ruby models TCP Sockets and how we can make a good use of it.

Presented at: WindyCityRails 2016

Transcript

1. TCP Socket Programming in Ruby
2. My name is Sebastián Sogamoso Tweet to me @sebasoga
3. Why?
6. API
7. API REST
8. REST JSON API
9. REST JSON XML API
10. API REST JSON SOAP XML
11. API REST WSDL JSON SOAP XML
16. Line protocol
17. “CONTROLLER_V":4-5:,"SOFTWARE_V":1-1\n set engine "on"=true,"rpm"=100 1434055562000000000 set led "on"=true,"color"="green" 1434055562000010000\n\n
18. What is a Socket?
19. Endpoints of a bidirectional communication channel
20. Sockets speak to other sockets using standard Unix file descriptors
22. “Everything (in Unix) is a file”
23. Yes, sockets act like files
24. The end @sebasoga
28. TCP Sockets programming in Ruby?
31. C programs for which Ruby has bindings
32. Create an endpoint for communication Prepare a socket for incoming connections Assign a socket to an address socket(2) listen(2) bind(2)
33. Connect to a socket in the given address Send a stream to the connected socket Manage new incoming connections connect(2) write(2) accept(2)
34. Receive socket’s incoming stream End connection with peer socket Perform synchronous I/O multiplexing read(2) close(2) select(2)
39. Berkley Socket API
40. Client / Server Lifecycle
41. Server
42. socket(2) Server
43. Server bind(2) socket(2) 127.0.0.1:3000
44. bind(2) socket(2) 127.0.0.1:3000 Server
45. bind(2) socket(2) 127.0.0.1:3000 Server
46. listen(2) bind(2) socket(2) Server
47. listen(2) bind(2) socket(2) Client Server
48. socket(2) listen(2) bind(2) socket(2) Client Server
49. socket(2) connect(2) listen(2) bind(2) socket(2) Client Server
50. socket(2) connect(2) listen(2) bind(2) socket(2) Client Server
51. socket(2) connect(2) accept(2) listen(2) bind(2) socket(2) Client Server
52. socket(2) connect(2) accept(2) listen(2) bind(2) socket(2) Client Server
53. socket(2) connect(2) accept(2) listen(2) bind(2) socket(2) Client Server
54. Client socket(2) connect(2) accept(2) listen(2) bind(2) socket(2) SYN Server
55. Client socket(2) connect(2) accept(2) listen(2) bind(2) socket(2) SYN ACK Server
56. Client socket(2) connect(2) accept(2) listen(2) bind(2) socket(2) SYN ACK ACK Server
57. Client socket(2) connect(2) write(2) accept(2) listen(2) bind(2) socket(2) Server
58. Client socket(2) connect(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) Server
59. Client socket(2) connect(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) Request is processed Server
60. Client socket(2) connect(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) write(2) Server
61. Client socket(2) connect(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) write(2) Server
62. Client socket(2) connect(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) write(2) read(2) Server
63. Client socket(2) connect(2) write(2) read(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) Server
64. Client socket(2) connect(2) write(2) read(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) close(2) Server
65. Client socket(2) connect(2) write(2) read(2) close(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) Server
66. Client socket(2) connect(2) write(2) read(2) close(2) write(2) read(2) accept(2) listen(2) bind(2) socket(2) close(2) Server
67. This is how those system calls look like in Ruby
68. The server
69. require ‘socket'
70. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM, 0)
71. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM, 0) Domain
72. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, _, _)
73. require ‘socket' # Create a new TCP socket socket = Socket.new(:INETv6, _, _)
74. require ‘socket' # Create a new TCP socket socket = Socket.new(:UNIX, _, _)
75. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM, 0) Type
76. require ‘socket' # Create a new TCP socket socket = Socket.new(_, :STREAM, _)
77. require ‘socket' # Create a new TCP socket socket = Socket.new(_, :DRAM, _)
78. require ‘socket' # Create a new TCP socket socket = Socket.new(_, :RAW, _)
79. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM, 0) Protocol
80. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM)
81. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM)
82. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM) # Create a C struct to hold the address for listening address = Socket.pack_sockaddr_in(5000,‘127.0.0.1’) socket.bind(address)
83. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM) # Create a C struct to hold the address for listening address = Socket.pack_sockaddr_in(5000,‘127.0.0.1’) socket.bind(address) # Start listening for incoming connections socket.listen(5) client.close
84. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM) # Create a C struct to hold the address for listening address = Socket.pack_sockaddr_in(5000,‘127.0.0.1’) socket.bind(address) # Start listening for incoming connections socket.listen(5) client.close
85. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM) # Create a C struct to hold the address for listening address = Socket.pack_sockaddr_in(5000,‘127.0.0.1’) socket.bind(address) # Start listening for incoming connections socket.listen(Socket::SOMAXCONN) client.close
86. require ‘socket' # Create a new TCP socket socket = Socket.new(:INET, :STREAM) # Create a C struct to hold the address for listening address = Socket.pack_sockaddr_in(5000,‘127.0.0.1’) socket.bind(address) # Start listening for incoming connections socket.listen(Socket::SOMAXCONN) client.close
87. require ‘socket' Socket.tcp_server_loop(5000) do |socket, client_addrinfo| begin socket.listen(Socket::SOMAXCONN) ensure c.close end end
88. The client
89. require ‘socket’ # Create a new TCP socket socket = Socket.new(:INET, :STREAM) address = Socket.pack_sockaddr_in(5000,’127.0.0.1’) # Use connect to get the server client.connect(address) client.close
90. require ‘socket’ # Create a new TCP socket socket = Socket.new(:INET, :STREAM) address = Socket.pack_sockaddr_in(5000,’127.0.0.1’) # Use connect to get the server client.connect(address) client.close
91. require ‘socket’ Socket.tcp(‘127.0.0.1’, 5000) do |socket| begin ensure socket.close end end # or socket = TCPSocket.new(‘127.0.0.1’, 5000)
92. Socket I/O
93. require 'socket' module WCR class Server def start @server = ::TCPServer.new(port) ::Socket.accept_loop(@server) do |socket| # Read from the connection until EOF request = socket.read # Process the request response = process(request) # Write back the result of the hash operation socket.write(response) socket.close end end end
94. require 'socket' module WCR class Server def start server = ::TCPServer.new(port) ::Socket.accept_loop(server) do |socket| # Read from the connection until EOF request = socket.read # Process the request response = process(request) # Write back the result of the hash operation socket.write(response) socket.close end end end
95. require 'socket' module WCR class Server def start server = ::TCPServer.new(port) ::Socket.accept_loop(server) do |socket| # Read from the connection until EOF request = socket.read # Process the request response = process(request) # Write back the result of the hash operation socket.write(response) socket.close end end end
96. require 'socket' module WCR class Server def start server = ::TCPServer.new(port) ::Socket.accept_loop(server) do |socket| # Read from the connection until EOF request = socket.read # Process the request response = process(request) # Write back the result of the hash operation socket.write(response) socket.close end end end
97. require 'socket' module WCR class Server def start server = ::TCPServer.new(port) ::Socket.accept_loop(server) do |socket| # Read from the connection until EOF request = socket.read # Process the request response = process(request) # Write back the result of the hash operation socket.write(response) socket.close end end end
98. require 'socket' module WCR class Server def start server = ::TCPServer.new(port) ::Socket.accept_loop(server) do |socket| # Read from the connection until EOF request = socket.read # Process the request response = process(request) # Write back the result of the hash operation socket.write(response) socket.close end end end
99. require 'socket' module WCR class Server def start server = ::TCPServer.new(port) ::Socket.accept_loop(server) do |socket| # Read from the connection until EOF request = socket.read # Process the request response = process(request) # Write back the result of the hash operation socket.write(response) socket.close end end end
100. require 'socket' module WCR class Client atrr_accessor :host, :port def request(string) # Create a new connection for each operation socket = ::TCPSocket.new(host, port) socket.write(string) # Send EOF after writing the request socket.close_write # Read until EOF to get the response socket.read end end end
101. require 'socket' module WCR class Client atrr_accessor :host, :port def request(string) # Create a new connection for each operation socket = ::TCPSocket.new(host, port) socket.write(string) # Send EOF after writing the request socket.close_write # Read until EOF to get the response socket.read end end end
102. require 'socket' module WCR class Client atrr_accessor :host, :port def request(string) # Create a new connection for each operation socket = ::TCPSocket.new(host, port) socket.write(string) # Send EOF after writing the request socket.close_write # Read until EOF to get the response socket.read end end end
103. require 'socket' module WCR class Client atrr_accessor :host, :port def request(string) # Create a new connection for each operation socket = ::TCPSocket.new(host, port) socket.write(string) # Send EOF after writing the request socket.close_write # Read until EOF to get the response socket.read end end end
104. require 'socket' module WCR class Client atrr_accessor :host, :port def request(string) # Create a new connection for each operation socket = ::TCPSocket.new(host, port) socket.write(string) # Send EOF after writing the request socket.close_write # Read until EOF to get the response socket.read end end end
105. What’s next?
106. • Buffering • Non blocking I/O • Multiplexing connections • Timeouts • Network architecture patterns
107. Interested?
109. sourcediving.com @sebasoga
110. Thanks!