#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
 
-PROXY_TOKEN = 'http_'
-REGEX = '\\$' + PROXY_TOKEN + '[a-z_0-9]+\\b'
+# 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[len(PROXY_TOKEN)+1:]
+            new_var = name[6:].replace('_', '-')
             values[name[1:]] = self.headers.get(new_var, '-')
         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):
-        _lock.acquire()
-        message = Template(self.format)

[Vasily Kuznetsov, 2017/08/11 17:31:47]

You should probably use try/finally here with the locking. Otherwise one error
in formatting or writing will bring the whole thing down by not releasing the
lock.

-        self.info_file.write(message.safe_substitute(args))
-        if self.info_file is sys.stdout:
-            self.info_file.flush()
-        _lock.release()
+        message = Template(self.format).safe_substitute(args) + '\n'
+        with _lock:
+            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,
             'bytes_sent': len(content),
         }
         values.update(self.get_header_values())
-        self.write_info(values)
-        self.send_response(status)
-        self.send_header('Content-Type', values['content_type'])
-        self.send_header('Content-Length', values['content_length'])
-        self.end_headers()
-        self.wfile.write(content)
+        try:
+            self.write_info(values)
+            self.send_simple_response(status, content)
+        except:
+            traceback.print_exc(file=sys.stderr)
+            self.send_simple_response(500)
 
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument('--port', action='store',
                         default=8000, type=int,
                         nargs='?',
                         help='Port to use [default: 8000]')
     parser.add_argument('--response', action='store',
                         type=str, nargs='?', default='OK',
                         help='The response send to the client')
     parser.add_argument('--format', action='store',
                         type=str, nargs='?',
                         default=DEFAULT_LOG,
                         help='Format of the log ouput')
-    parser.add_argument('info_file', action='store',

[Vasily Kuznetsov, 2017/08/11 17:31:47]

I'm not sure if "info_file" is the best name, it sounds a bit unclear. How about
"output_file"?

+    parser.add_argument('output', action='store',
                         type=str, nargs='?', default='-',
                         help='The file where the logs will be written')
     args = parser.parse_args()
-    setattr(Handler, 'format', args.format)
-    setattr(Handler, 'response', args.response)
-    server_address = ('', args.port)
-    httpd = HTTPServer(server_address, Handler)
-    if args.info_file and args.info_file != '-':
-        fh = open(args.info_file, 'a')
+    if args.output and args.output != '-':
+        fh = open(args.output, 'a')
     else:
-        fh = sys.stdout
-    setattr(Handler, 'info_file', fh)

[Vasily Kuznetsov, 2017/08/11 17:31:47]

I think it would be more clear to order the steps like this:

# parse args
# open the file
Handler.format = args.format
Handler.response = args.reponse
Handler.info_file = fh
httpd = HTTPServer(('', args.port), Handler)
try:
    httpd.serve_forever()
except:
    # close the file

What do you think?

+        fh = open(sys.stdout.fileno(), 'w', closefd=False)
     try:
+        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.info_file != '-':
-            fh.close()
+    finally:
+        fh.close()