low level life

「Webを支える技術」を読んでいたら、HTTP GETしてみたくなったのでpythonのsocketを使ってやってみました。
サーバー側はsocketじゃなくてflaskです。apacheとか、まぁ、ふつうにgoogleとかにアクセスしてもいいよね。

http_request_tester.py

# vim: fileencoding=utf-8
import socket
import urllib

class Response(object):
    HEADER_BODY_SPLITTER = "\r\n\r\n"

    def __init__(self, response):
        split_index = response.index(self.HEADER_BODY_SPLITTER)
        self.header = response[:split_index]
        self.status = self._get_status(self.header)
        self.headers = self._header2dict(self.header)
        self.body = response[split_index+len(self.HEADER_BODY_SPLITTER):]

    def _get_status(self, header):
        return header[:header.index("\r\n")]

    def _header2dict(self, header):
        headers = {}
        for line in header.splitlines()[1:]:
            headers[line[:line.index(":")]] = line[line.index(":")+1:].strip()
        return headers

class HttpRequestTester(object):
    sock = None

    def __init__(self, host='localhost', port=80):
        self.host = host
        self.ip = socket.gethostbyname(host)
        self.port = port

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        pass

    def _request(self, request_message):
        try:
            self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            self.sock.connect((self.ip, self.port))

            self.sock.sendall(request_message)

            response = ""
            while True:
                data = self.sock.recv(1024)
                if not data:
                    break
                response += data

        finally:
            if self.sock:
                self.sock.close()
                self.sock = None

        return Response(response)

    def get(self, path, params={}):
        template = "GET {path} HTTP/1.1\n"
        template += "Host: {host}\n"
        template += "Connection: {connection}\n"
        template += "User-Agent: {user_agent}\n"
        template += "Accept-Language: {accept_language}\n"
        template += "Referer: {referer}\n"
        template += "\n"
        request_message = template.format(path=path, host=self.host,
                        connection='close',
                        user_agent='HttpRequestTester/0.0.1',
                        accept_language='ja',
                        referer='')

        print "REQUEST: {request}".format(request=request_message)

        return self._request(request_message)

    def post(self, path, params={}):
        template = "POST {path} HTTP/1.1\n"
        template += "Host: {host}{port}\n"
        template += "Content-Type: {content_type}\n"
        #template += "Connection: {connection}\n"
        #template += "User-Agent: {user_agent}\n"
        #template += "Accept-Language: {accept_language}\n"
        #template += "Referer: {referer}\n"
        template += "\n"
        template += "{param_string}\n"
        template += "\n"
        request_message = template.format(path=path, host=self.host,
                        connection='close',
                        content_type='text/plain; charset=utf-8',
                        user_agent='HttpRequestTester/0.0.1',
                        accept_language='ja',
                        referer='',
                        port=":"+str(self.port) if self.port!=80 else "",
                        param_string=urllib.urlencode(params))

        print "REQUEST: {request}".format(request=request_message)

        return self._request(request_message)

if __name__ == "__main__":
    HOST = 'localhost'
    PORT = 5000

    http = HttpRequestTester(HOST, PORT)
    res = http.get("/")
    print res.status
    print res.headers
    print res.body
    raw_input()

    res = http.post("/", params={"hoge":"hogehoge"})
    print res.status
    print res.headers
    print res.body
    raw_input()

flaskで作ったテストサーバー

from flask import Flask, request

app = Flask(__name__)

@app.route("/", methods=["GET", "POST"])
def post():
    if request.method == "GET":
        return "GET DESU"

    return "POST DESU"

if __name__ == '__main__':
    app.run(debug=True)

GETやPOSTのConnectionとかは適当。
「Webを支える技術」の８章とか巻末あたりに書いてそうだけど、まだ読んでないのでまた今度。

参考

• Pythonでソケット通信 – mihoのお勉強ブログ（仮）
• 17.2 socket — 低レベルネットワークインターフェース