Issue 395 - Filter hits statistics backend

sitescripts/filterhits/web/submit.py

+# coding: utf-8
+
+# This file is part of the Adblock Plus web scripts,
+# Copyright (C) 2006-2015 Eyeo GmbH
+#
+# Adblock Plus is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# Adblock Plus is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+
+import json
+import MySQLdb
+import tempfile
+import time
+import os
+from datetime import datetime
+from errno import EEXIST
+
+from sitescripts.web import url_handler
+from sitescripts.utils import get_config, setupStderr
+from sitescripts.filterhits import common, db, geometrical_mean
+
+def log_filterhits(data, basepath, query_string):
+  """
+  This logs the provided filterhits data as JSON to a file named after
+  the current timestamp in a directory named after the current date.
+  """
+  now = time.gmtime()
+
+  dir_name = time.strftime("%Y-%m-%d", now)
+  path = os.path.join(basepath, dir_name)
+  try:
+    os.makedirs(path)
+  except OSError as e:
+    if e.errno != EEXIST:
+      raise
+
+  with tempfile.NamedTemporaryFile(
+    prefix = str(int(time.mktime(now))) + "-",
+    suffix = ".log",
+    dir = path,
+    delete = False
+  ) as f:
+    print >> f, "[%s] \"%s\"" % (time.strftime('%d/%b/%Y:%H:%M:%S', now),
+                                 query_string)

[Wladimir Palant, 2015/03/27 16:29:06]

I wonder whether quotation marks in the query string will break any of the tools
you wrote. And before you object that most browsers will turn quotation marks
into %22 - sure, but anybody using telnet or an older IE version can still send
them to the server.

Given that a query string cannot have whitespace in it due to specifics of the
HTTP protocol - why use quotation marks as delimiters here?

[kzar, 2015/03/27 22:15:00]

(Give me a little credit, I would not assume data sent from the client is safe /
correct.)

Done.

+    print >> f, json.dumps(data)

[Sebastian Noack, 2015/03/27 16:31:04]

json.dump(data, f)

[kzar, 2015/03/27 22:15:00]

Done.

+    return f.name
+
+@url_handler("/submit")
+def submit(environ, start_response):
+  setupStderr(environ["wsgi.errors"])
+  config = get_config()
+
+  # Check that this is a POST request
+  if environ["REQUEST_METHOD"] != "POST":
+    return common.show_error("Unsupported request method", start_response)
+
+  # Parse the submitted JSON
+  try:
+    data = json.loads(environ["wsgi.input"].read(int(environ["CONTENT_LENGTH"])))
+  except (KeyError, IOError, ValueError):
+    return common.show_error("Error while parsing JSON data.", start_response)
+
+  # Make sure the submitted data was contained within an object at least
+  if not isinstance(data, dict):
+    return common.show_error("Error, data must be contained within an object.", start_response)
+
+  # Log the data to a file
+  if not db.testing:
+    log_dir = config.get("filterhitstats", "log_dir")
+    try:
+      log_file = log_filterhits(data, log_dir, environ.get("QUERY_STRING", ""))
+    except (OSError, IOError):
+      return common.show_error("Failed to write data to log file!", start_response,
+                              "500 Logging error")

[Wladimir Palant, 2015/03/27 16:29:06]

This seems to be an unexpected error, one that is worth logging. Do
traceback.print_exc() as well here?

[kzar, 2015/03/27 22:15:00]

Done.

+
+  # Update the geometrical_mean aggregations in the database
+  interval = config.get("filterhitstats", "interval")
+  try:
+    db_connection = db.connect()
+    try:
+      db.write(db_connection, geometrical_mean.update(interval, data))
+    finally:
+      db_connection.close()
+  except (KeyError, MySQLdb.Error), e:
+    # Updating the aggregations in the database failed for whatever reason,
+    # log the details but continue to return 200 OK to the client to avoid
+    # re-transmission of the data.
+    if not db.testing:
+      processing_error_log = os.path.join(config.get("filterhitstats", "log_dir"),
+                                     "processing-errors.log")
+      with open(processing_error_log, "a+") as f:
+        if isinstance(e, KeyError):
+          message = "KeyError (%s) when processing data file %s" % (str(e.args[0]), log_file)
+        elif isinstance(e, MySQLdb.Error):
+          message = "MySQL error (%d) when processing data file %s: \"%s\"" % (e.args[0], log_file, e.args[1])
+        print >> f, "[%s] %s" % (datetime.now().strftime('%d/%b/%Y:%H:%M:%S %z'), message)

[Wladimir Palant, 2015/03/27 16:29:06]

I'd suggest using traceback module here instead of generating custom messages.
This should also allow logging any error types rather than only two.

[kzar, 2015/03/27 22:15:00]

Done.

+
+  # Send back a 200 OK response
+  response_headers = [("Content-type", "text/plain")]
+  start_response("200 OK", response_headers)
+  return []