a simple caching http proxy

httpcache.py

#! /usr/bin/python3

# A simple HTTP proxy which does caching of requests.
# "Inspired" by: https://gist.github.com/justinmeiners/24dcf5904490b621220bed643651f681
# but updated with 
#- a clean exit on signal allowing it to be easily popped by another script using subprocess
#- tcp socket reuse to avoid the tcp socket already in use if popped often
#- a cache directory to avoid a lot of files just being in the middle
# 
# use it by getting 'http://localhost:8000/www.kernel.org' to get http://www.kernel.org 
# duplicate the class+tcpserver and listen on another port for your https needs (alter line 40 in the duplicate);
# it will share the cache

import http.server
import socketserver
import urllib.request
import shutil
import os
import hashlib
import signal


cache_base = "./cache/"
httpd = None

def exit_gracefully(sig,stack):
    #print("received sig %d, quitting" % (sig))
    httpd.server_close()
    exit()

class CacheHandler(http.server.SimpleHTTPRequestHandler):
    def do_GET(self):
      m = hashlib.md5()
      m.update(self.path.encode("utf-8"))
      cache_filename = cache_base + m.hexdigest() +".cached"

      if not os.path.exists(cache_filename):
          #print("cache miss "+ self.path)
          with open(cache_filename + ".temp", "wb") as output:
            #print(self.path)
            req = urllib.request.Request("http:/" + self.path)
            for k in self.headers:
                if k not in ["Host"]:
                    req.add_header(k, self.headers[k])
            resp = urllib.request.urlopen(req)
            shutil.copyfileobj(resp, output)
            os.rename(cache_filename + ".temp", cache_filename)
      #else:
          #print("cache hit "+ self.path)
      
      with open(cache_filename, "rb") as cached:
          self.send_response(200)
          self.end_headers()
          shutil.copyfileobj(cached, self.wfile)

signal.signal(signal.SIGINT, exit_gracefully)
signal.signal(signal.SIGTERM,exit_gracefully)
socketserver.TCPServer.allow_reuse_address = True
httpd = socketserver.TCPServer(("", 8000), CacheHandler)
if not os.path.exists(cache_base):
    os.mkdir(cache_base)

httpd.serve_forever()

Thanks for your contribution! I used it today. I may add a few lines of yours back to mine.

Does

    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        sys.exit(0)

Resolve the same issue as your signal handlers?