server.py

   1 # Copyright (C) 2008, Thomas Leonard
   2 # See the README file for details, or visit http://0install.net.
   3
   4 from logging import info, debug
   5 import socket
   6 import select, os
   7 from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
   8
   9 from zeroinstall.zerostore import Stores, BadDigest, NotStored
  10
  11 stores = Stores()
  12
  13 def serve(host, port):
  14         """Listen on (host, port) for broadcast queries and fetch requests."""
  15
  16         # The UDP socket listens for broadcast queries about who has
  17         # particular digests
  18         udp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
  19         udp_socket.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
  20         udp_socket.bind((host or '<broadcast>', port))
  21
  22         # The TCP socket is used to send the requested implementations
  23         http_server = HTTPServer((host or '', port), FetchRequestHandler)
  24
  25         info("0share started and listening for requests...")
  26         for x in stores.stores:
  27                 info("Serving implementations from %s", x)
  28         while True:
  29                 ready = select.select([udp_socket, http_server.socket], [], [])[0]
  30                 if udp_socket in ready:
  31                         handle_query(udp_socket)
  32                 if http_server.socket in ready:
  33                         http_server.handle_request()
  34
  35 def handle_query(ss):
  36         data, addr = ss.recvfrom(128)
  37         info("Request from %s: %s", addr, repr(data))
  38         if not data.startswith('0share\n'):
  39                 info("Not our format. Ignoring.")
  40                 return
  41         digests = data.split('\n')[1:]
  42         got = []
  43         try:
  44                 for d in digests:
  45                         if not d: raise BadDigest("Empty digest!")
  46                         try:
  47                                 stores.lookup(d)
  48                                 info("Yes, we have %s", d)
  49                                 got.append(d)
  50                         except NotStored:
  51                                 info("No, we don't have %s", d)
  52         except BadDigest, ex:
  53                 info("Bad request: %s", str(ex))
  54                 return
  55         if got:
  56                 info("Sending reply...")
  57                 ss.sendto('0share-reply\n' + '\n'.join(got), addr)
  58
  59 class FetchRequestHandler(BaseHTTPRequestHandler):
  60         def do_GET(self):
  61                 info("GET %s", self.path)
  62                 bits = self.path.split('/')
  63                 if len(bits) == 3 and bits[0] == '' and bits[1] == 'implementation':
  64                         digest = bits[2]
  65                 else:
  66                         self.send_error(404, "Not an implementation")
  67                         return
  68
  69                 try:
  70                         path = stores.lookup(digest)
  71                 except (BadDigest, NotStored), ex:
  72                         info("Lookup error: %s", str(ex))
  73                         self.send_error(404, "Implementation %s not found" % digest)
  74                         return
  75
  76                 self.send_response(200, "OK")
  77                 self.send_header('Content-Type', 'application/x-compressed-tar')
  78                 self.end_headers()
  79
  80                 import tarfile
  81                 archive = tarfile.open(mode = 'w|gz', fileobj = self.wfile)
  82                 for x in os.listdir(path):
  83                         if x != '.manifest':
  84                                 debug("Adding %s", x)
  85                                 archive.add(os.path.join(path, x), x)
  86                 archive.close()