#2687 - Include mimeo python module

modules/adblockplus/files/mimeo.py

 #!/usr/bin/env python3
 
 import argparse
 import re
 import sys
 import threading
 import traceback
 
 from http.server import BaseHTTPRequestHandler, HTTPServer
 from string import Template
 
 # The token used for the headers passed by nginx is: http_
 REGEX = r'\$http_\w+\b'
 DEFAULT_LOG = '$remote_addr - - [$time_local] "$request" $status $bytes_sent'
 _lock = threading.Lock()
 
 
 class Handler(BaseHTTPRequestHandler):
     def get_header_values(self):
         values = {}
         headers = re.findall(REGEX, self.format)
         for name in headers:
-            new_var = name[6:]
+            new_var = name[6:].replace('_', '-')
             values[name[1:]] = self.headers.get(new_var, '-')

[mathias, 2017/08/18 08:47:43]

Does this understand translation between i.e. `X-Forwarded-For` and
`x_forwarded_for`?

[f.lopez, 2017/08/19 00:51:00]

No, one has to match them manually. 
proxy_set_header X-Forwarded-For $http_x_forwarded_for;

Other option could be to use a list/tuple/something to match all cases?
('x_forwarded_for', X_Forwarded_for', 'X-Forwarded-For')

Or set a standard to for how the headers should look like.

What do you think?

[mathias, 2017/08/19 15:06:08]

No idea what you mean. I was referring to this code passing on
lowercase_and_underscore_separated_header_names were one would expect
Titlelized-And-Minus-Separated-Header-Names and asking if self.headers.get() can
indeed handle that or if you need to string-transform your input first. I would
guess the latter, but only replacing underscores with minuses (the starting
letters should be examined in case-insensitive fashion anyway, if you're lucky
that is).

         return values
 
     def send_simple_response(self, status, response=None):
         self.send_response(status)
         self.end_headers()
         if response is None:
             response = bytes(self.responses[status][0], 'UTF-8')
         self.wfile.write(response)
 
     def write_info(self, args):
+        message = Template(self.format).safe_substitute(args) + '\n'
         with _lock:
-            message = Template(self.format)
-            self.output.write(message.safe_substitute(args) + '\n')

[mathias, 2017/08/18 08:47:44]

Shouldn't the template stuff happen before, so that the lock would only be held
for writing a string and flushing?

[f.lopez, 2017/08/19 00:51:00]

Done.

+            self.output.write(message)
             self.output.flush()
 
     def do_POST(self):
         status = 200
         content = bytes(self.response, 'UTF-8')
         values = {
             'remote_addr': self.address_string(),
             'time_local': self.log_date_time_string(),
             'request': self.requestline,
             'status': status,
@@ skipping 21 matching lines @@
                         type=str, nargs='?',
                         default=DEFAULT_LOG,
                         help='Format of the log ouput')
     parser.add_argument('output', action='store',
                         type=str, nargs='?', default='-',
                         help='The file where the logs will be written')
     args = parser.parse_args()
     if args.output and args.output != '-':
         fh = open(args.output, 'a')
     else:
-        fh = sys.stdout

[mathias, 2017/08/18 08:47:43]

If you would `os.open(sys.stdout.fileno(), 'w', 0)` you could avoid conditionals
like the one around `fh.close()` later on.

[Vasily Kuznetsov, 2017/08/18 12:49:57]

This doesn't work (at least in Python 3.6), but what you can indeed do is
`open(sys.stdout.fileno(), 'w', closefd=False)` using builtin open, not the one
from os module. This will give you another file-like object that will use the
same file descriptor as `sys.stdout` under the hood but will not close it when
its closed. This way you can indeed eliminate the closing `if` that Matze
doesn't like.

[f.lopez, 2017/08/19 00:51:00]

Done.

-    Handler.output = fh
-    Handler.format = args.format
-    Handler.response = args.response
-    server_address = ('', args.port)
-    httpd = HTTPServer(server_address, Handler)
+        fh = open(sys.stdout.fileno(), 'w', closefd=False)
     try:

[mathias, 2017/08/18 08:47:44]

This exception handling should enclose everything since the file has been
opened, at least everything that is not an assignment and can possibly fail
(e.g. the HTTPServer instantiation above).

[f.lopez, 2017/08/19 00:51:01]

Done.

+        Handler.output = fh
+        Handler.format = args.format
+        Handler.response = args.response
+        server_address = ('', args.port)
+        httpd = HTTPServer(server_address, Handler)
         httpd.serve_forever()
-    except:
-        if args.output != '-':
-            fh.close()
+    finally:
+        fh.close()