Build your own webserver with PHP

Transcript

1. Build your own
   web server
   with
   

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2. @igorwesome
   

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3. Event-driven, non-blocking I/O with PHP.
   

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5. When you open your web
   browser…
   
   !
   What actually happens?
   

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7. http://igor.io/
   

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8. DNS
   Where is igor.io?
   

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9. DNS
   176.58.127.253
   

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10. 176.58.127.253
    

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11. 2^16!
    65535!
    TCP ports
    

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12. TCP port 80
    

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13. SYN
    

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14. SYN/ACK
    

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15. ACK
    

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17. GET / HTTP/1.1!
    Host: igor.io
    

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18. HTTP/1.1 200 OK!
    Content-Type: text/html!
    !
    …
    

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19. HTTP
    TCP
    IP
    

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20. Layers
    +---+--------------+----------------+
    | 7 | Application | HTTP, FTP, DNS |
    | 6 | Presentation | TLS |
    | 5 | Session | TCP |
    | 4 | Transport | TCP, UDP |
    | 3 | Network | IP |
    | 2 | Data Link | ARP, PPP |
    | 1 | Physical | |
    +---+--------------+----------------+
    

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21. http://igor.io/
    

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22. http://igor.io:80/
    

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23. http://igor.io:80/
    }
    DNS (layer 7)!
    resolves to!
    IP (layer 3)
    

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24. http://igor.io:80/
    }
    TCP (layer 4)
    

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25. http://igor.io:80/
    }
    TLS (layer 6)!
    HTTP (layer 7)
    }
    HTTP (layer 7)
    

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26. The Socket API
    

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27. ________
    < socket >
    --------
    \ ^__^
    \ (oo)\_______
    (__)\ )\/\
    ||----w |
    || ||
    

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28. #include
    #include
    #include
    socket()
    --------
    bind()
    listen()
    accept()
    --------
    connect()
    

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29. Syscalls
    Process
    socket!
    bind!
    listen!
    accept!
    connect!
    !
    read!
    write!
    close!
    !
    

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30. Stream Sockets
    

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31. I will show you
    
    Les Codes
    00
    

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32. HTTP: The Protocol
    

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33. Request
    GET / HTTP/1.1 Host: igor.io

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34. Response
    HTTP/1.1 200 OK Content-Length: 2 Hi

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35. Verbs
    •GET
    
    •POST
    

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36. Verbs
    •GET
    
    •POST
    
    •PUT
    
    •DELETE
    

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37. Verbs
    •GET
    
    •POST
    
    •PUT
    
    •DELETE
    
    !
    •HEAD
    
    •OPTIONS
    
    •TRACE
    
    •CONNECT
    

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38. • 1xx - Special protocol stuff
    
    • 2xx - All good
    
    • 3xx - Redirection
    
    • 4xx - You messed up
    
    • 5xx - I messed up
    Status codes
    

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39. Keep-Alive
    

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40. Streaming
    • Transfer-Encoding: chunked
    
    • dechex(strlen($chunk)) \r\n $chunk \r\n
    
    • 0 \r\n \r\n
    

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41. General weirdness
    • Trailers
    
    • Repeated headers
    
    • 100 Continue
    

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42. ABNF is
    very permissive
    

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43. HTTP/1.1
    RFC 2616
    read it.
    

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44. Parsing
    

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45. Request
    GET / HTTP/1.1 Host: igor.io

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46. More codes
    01, 02
    

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47. Problem?
    • Incomplete HTTP parser
    
    • Missing error handling
    
    • Assumption: request can be read in one go
    
    • Assumption: request no larger than 512 bytes
    
    • Assumption: request/response body fits in memory
    
    • Blocking I/O
    

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48. Non-blocking I/O
    

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49. Even more codes
    03-08
    

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50. Unreadable
    

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51. LOL error handling
    

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52. Writing your own
    HTTP server is hard
    

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53. Don’t do it.
    

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55. Questions?
    joind.in/9277
    
    !
    reactphp.org
    
    !
    @igorwesome
    
    !
    !
    github.com/igorw/webserver-zceu
    

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56. Bonus
    • Memory leaks
    
    • Too fast reads / too slow writes
    
    • libevent / libev / libuv
    
    • Promises
    
    • Generators
    
    • pthreads
    
    • WebSockets
    

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57. Logo credits
    • Netscape
    
    • Apache
    
    • FreeBSD
    
    • Erlang
    

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