http.server rfile read blocking in python - python

Trying to build a simple python3 HTTP Server with http.server:
import http.server
from http.server import HTTPServer, BaseHTTPRequestHandler
import socketserver
class Handler(BaseHTTPRequestHandler):
def do_PATCH(self):
print ("do_Patch called")
contentLength = int(self.headers['content-length'])
res = self.rfile.read(contentLength)
self.send_response(200)
self.send_header('Content-type', 'text/plain')
self.end_headers()
self.wfile.write('Something brilliant'.encode())
httpd = HTTPServer(("127.0.0.1",33181),Handler)
httpd.serve_forever()
Problem is that self.rfile.read() is blocking, so if I don't get the content-length exactly right I either get too little data or I hang.. Docs I've found says it's supposed to throw an exception in non-blocking mode but I've not found out how to set non-blocking mode.
I can get around this by setting the content-length as above, but I can also corrupt the content-length which hangs the thread:
import http.client
myValueableString = "Shorter than 300"
for mylen in [len(myValueableString), 300]:
conn = http.client.HTTPConnection("127.0.0.1",33181)
conn.request("PATCH","/test",myValueableString ,{'Content-length': mylen})
print(conn.getresponse().read().decode())
Is there any good way to 1) Force finding the "true" length of rfile stream, or 2) Force a timeout or 3) Enable "non-blocking" mode? I realize the code isn't recommended for production but this is the only real stumbling block I've encountered.

Related

Sending and Formatting Variable Through HTTP

Hey so I have been trying to make a script that just reads the amount of followers someone has and then send the amount of followers back to the server that requested it. I have absolutely no idea how http works or how to properly format a variable to go across it. Whenever I make a request I get a bad response error. I know what is causing this, it’s the variable and how python formats it, but how would I send this over http? Any help? (Also this server won't have very much traffic at all)
import selenium
from selenium import webdriver
import time
import http
import http.server
import socketserver
from http.server import HTTPServer, BaseHTTPRequestHandler
import json
driver = webdriver.Chrome()
class requestHandler(BaseHTTPRequestHandler):
def do_GET(self):
self.send_response(200)
self.send_header('content-type', 'text/html')
self.end_headers
print(self.path[1:])
driver.get('https://www.tiktok.com/#%s?lang=en' % self.path[1:])
FOLLOWERS = driver.find_element_by_xpath('//*[#id="main"]/div[2]/div[2]/div/header/h2[1]/div[2]/strong').text
driver.close
print(str(FOLLOWERS))
self.wfile.write((str(FOLLOWERS).encode()))
def main():
PORT = 8000
server = HTTPServer(('', PORT), requestHandler)
print('Server running on port %s' % PORT)
server.serve_forever()
if __name__ == '__main__':
main()```
You forgot to create a function call when ending the header.
self.end_headers()
is what you want (the round brackets are missing). otherwise, chrome won't recognize this as a valid HTTP response.
Interestingly, this code works when using firefox.

How to make an HTTP server listen on multiple ports? [duplicate]

I'm writing a small web server in Python, using BaseHTTPServer and a custom subclass of BaseHTTPServer.BaseHTTPRequestHandler. Is it possible to make this listen on more than one port?
What I'm doing now:
class MyRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):
def doGET
[...]
class ThreadingHTTPServer(ThreadingMixIn, HTTPServer):
pass
server = ThreadingHTTPServer(('localhost', 80), MyRequestHandler)
server.serve_forever()
Sure; just start two different servers on two different ports in two different threads that each use the same handler. Here's a complete, working example that I just wrote and tested. If you run this code then you'll be able to get a Hello World webpage at both http://localhost:1111/ and http://localhost:2222/
from threading import Thread
from SocketServer import ThreadingMixIn
from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
class Handler(BaseHTTPRequestHandler):
def do_GET(self):
self.send_response(200)
self.send_header("Content-type", "text/plain")
self.end_headers()
self.wfile.write("Hello World!")
class ThreadingHTTPServer(ThreadingMixIn, HTTPServer):
daemon_threads = True
def serve_on_port(port):
server = ThreadingHTTPServer(("localhost",port), Handler)
server.serve_forever()
Thread(target=serve_on_port, args=[1111]).start()
serve_on_port(2222)
update:
This also works with Python 3 but three lines need to be slightly changed:
from socketserver import ThreadingMixIn
from http.server import HTTPServer, BaseHTTPRequestHandler
and
self.wfile.write(bytes("Hello World!", "utf-8"))
Not easily. You could have two ThreadingHTTPServer instances, write your own serve_forever() function (don't worry it's not a complicated function).
The existing function:
def serve_forever(self, poll_interval=0.5):
"""Handle one request at a time until shutdown.
Polls for shutdown every poll_interval seconds. Ignores
self.timeout. If you need to do periodic tasks, do them in
another thread.
"""
self.__serving = True
self.__is_shut_down.clear()
while self.__serving:
# XXX: Consider using another file descriptor or
# connecting to the socket to wake this up instead of
# polling. Polling reduces our responsiveness to a
# shutdown request and wastes cpu at all other times.
r, w, e = select.select([self], [], [], poll_interval)
if r:
self._handle_request_noblock()
self.__is_shut_down.set()
So our replacement would be something like:
def serve_forever(server1,server2):
while True:
r,w,e = select.select([server1,server2],[],[],0)
if server1 in r:
server1.handle_request()
if server2 in r:
server2.handle_request()
I would say that threading for something this simple is overkill. You're better off using some form of asynchronous programming.
Here is an example using Twisted:
from twisted.internet import reactor
from twisted.web import resource, server
class MyResource(resource.Resource):
isLeaf = True
def render_GET(self, request):
return 'gotten'
site = server.Site(MyResource())
reactor.listenTCP(8000, site)
reactor.listenTCP(8001, site)
reactor.run()
I also thinks it looks a lot cleaner to have each port be handled in the same way, instead of having the main thread handle one port and an additional thread handle the other. Arguably that can be fixed in the thread example, but then you're using three threads.

Python multithread http server

I am trying to write a simple multithreaded http server which answers requests after 5 sec.
This code does not work, two simultaneous requests take 10 sec to complete, and I don't understand why.
from socketserver import ThreadingMixIn
from http.server import SimpleHTTPRequestHandler, HTTPServer, BaseHTTPRequestHandler
class ThreadingSimpleServer(ThreadingMixIn, HTTPServer):
pass
import sys
import os
import time
class Handler(BaseHTTPRequestHandler):
def do_GET(self):
time.sleep(5)
self.send_response(200)
self.send_header('Content-type','text/html')
self.end_headers()
self.wfile.write("answer")
return
server = ThreadingSimpleServer(('', 8000), Handler)
try:
while 1:
sys.stdout.flush()
server.handle_request()
except KeyboardInterrupt:
print("Finished")
You are calling handle_request, which handles one request after the other. You have to use serve_forever, so that the server can handle request automatically.

Setting up an HTTP server that listens over a file-socket

How can I use HTTPServer (or some other class) to set up an HTTP server that listens to a filesystem socket instead of an actual network socket? By "filesystem socket" I mean sockets of the AF_UNIX type.
HTTPServer inherits from SocketServer.TCPServer, so I think it's fair to say that it isn't intended for that use-case, and even if you try to work around it, you may run into problems since you are kind of "abusing" it.
That being said, however, it would be possible per se to define a subclass of HTTPServer that creates and binds Unix sockets quite simply, as such:
class UnixHTTPServer(HTTPServer):
address_family = socket.AF_UNIX
def server_bind(self):
SocketServer.TCPServer.server_bind(self)
self.server_name = "foo"
self.server_port = 0
Then, just pass the path you want to bind to by the server_address argument to the constructor:
server = UnixHTTPServer("/tmp/http.socket", ...)
Again, though, I can't guarantee that it will actually work well. You may have to implement your own HTTP server instead.
I followed the example from #Dolda2000 above in Python 3.5 and ran into an issue with the HTTP handler falling over with an invalid client address. You don't have a client address with Unix sockets in the same way that you do with TCP, so the code below fakes it.
import socketserver
...
class UnixSocketHttpServer(socketserver.UnixStreamServer):
def get_request(self):
request, client_address = super(UnixSocketHttpServer, self).get_request()
return (request, ["local", 0])
...
server = UnixSocketHttpServer((sock_file), YourHttpHandler)
server.serve_forever()
With these changes, you can perform an HTTP request against the Unix socket with tools such as cURL.
curl --unix-socket /run/test.sock http:/test
Overview
In case it help anyone else, I have created a complete example (made for Python 3.8) based on Roger Lucas's example:
Server
import socketserver
from http.server import BaseHTTPRequestHandler
class myHandler(BaseHTTPRequestHandler):
def do_GET(self):
self.send_response(200)
self.send_header('Content-type','text/html')
self.end_headers()
self.wfile.write(b"Hello world!")
return
class UnixSocketHttpServer(socketserver.UnixStreamServer):
def get_request(self):
request, client_address = super(UnixSocketHttpServer, self).get_request()
return (request, ["local", 0])
server = UnixSocketHttpServer(("/tmp/http.socket"), myHandler)
server.serve_forever()
This will listen on the unix socket and respond with "Hello World!" for all GET requests.
Client Request
You can send a request with:
curl --unix-socket /tmp/http.socket http://any_path/abc/123
Troubleshooting
If you run into this error:
OSError: [Errno 98] Address already in use
Then delete the socket file:
rm /tmp/http.socket

Why does my HTTP response using Python Sockets fail?

Code:
from socket import *
sP = 14000
servSock = socket(AF_INET,SOCK_STREAM)
servSock.bind(('',sP))
servSock.listen(1)
while 1:
connSock, addr = servSock.accept()
connSock.send('HTTP/1.0 200 OK\nContent-Type:text/html\nConnection:close\n<html>...</html>')
connSock.close()
When I go to the browser and type in localhost:14000, I get an error 101- ERR_CONNECTION_RESET The connection was reset? Not sure why! What am I doing wrong
Several bugs, some more severe than others ... as #IanWetherbee already noted, you need an empty line before the body. You also should send \r\n not just \n. You should use sendall to avoid short sends. Last, you need to close the connection once you're done sending.
Here's a slightly modified version of the above:
from socket import *
sP = 14000
servSock = socket(AF_INET,SOCK_STREAM)
servSock.bind(('',sP))
servSock.listen(1)
while 1:
connSock, addr = servSock.accept()
connSock.sendall('HTTP/1.0 200 OK\r\nContent-Type:text/html\r\nConnection:close\r\n\r\n<html><head>foo</head></html>\r\n')
connSock.close()
Running your code, I have similar errors and am unsure on their origins too. However, rather than rolling your own HTTP server, have you considered a built in one? Check out the sample below. This can also support POST as well (have to add the do_POST method).
Simple HTTP Server
from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
class customHTTPServer(BaseHTTPRequestHandler):
def do_GET(self):
self.send_response(200)
self.send_header('Content-type', 'text/html')
self.end_headers()
self.wfile.write('<HTML><body>Hello World!</body></HTML>')
return
def main():
try:
server = HTTPServer(('',14000),customHTTPServer)
print 'server started at port 14000'
server.serve_forever()
except KeyboardInterrupt:
server.socket.close()
if __name__=='__main__':
main()

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