From 45eec97bf34b6093f77bf6cac597cddcbd5720ba Mon Sep 17 00:00:00 2001
From: Noah Petherbridge <root@kirsle.net>
Date: Thu, 4 Dec 2014 15:56:20 -0800
Subject: [PATCH] Add exception e-mail handler

---
 rophako/app.py              | 11 +++++++
 rophako/jsondb.py           |  6 +++-
 rophako/utils.py            | 59 ++++++++++++++++++++++++++++++++++++-
 rophako/www/errors/500.html | 10 +++++++
 runserver.py                |  7 ++++-
 5 files changed, 90 insertions(+), 3 deletions(-)
 create mode 100644 rophako/www/errors/500.html

diff --git a/rophako/app.py b/rophako/app.py
index 6bef520..597c281 100644
--- a/rophako/app.py
+++ b/rophako/app.py
@@ -29,6 +29,7 @@ Config.load_plugins()
 
 from rophako import __version__
 from rophako.plugin import load_plugin
+from rophako.log import logger
 import rophako.model.tracking as Tracking
 import rophako.utils
 
@@ -156,6 +157,16 @@ def index():
     return catchall("index")
 
 
+@app.errorhandler(Exception)
+def catch_exception(error):
+    """Catch unexpected Python exceptions and e-mail them out."""
+    logger.error("INTERNAL SERVER ERROR: {}".format(str(error)))
+
+    # E-mail it out.
+    rophako.utils.handle_exception(error)
+    return rophako.utils.template("errors/500.html")
+
+
 @app.errorhandler(404)
 def not_found(error):
     return render_template('errors/404.html', **g.info), 404
diff --git a/rophako/jsondb.py b/rophako/jsondb.py
index 3650f43..26c296a 100644
--- a/rophako/jsondb.py
+++ b/rophako/jsondb.py
@@ -13,6 +13,7 @@ import json
 import time
 
 from rophako.settings import Config
+from rophako.utils import handle_exception
 from rophako.log import logger
 
 redis_client = None
@@ -137,7 +138,10 @@ def read_json(path):
         data = json.loads(text)
     except:
         logger.error("Couldn't decode JSON data from {}".format(path))
-        logger.error(text)
+        handle_exception(Exception("Couldn't decode JSON from {}\n{}".format(
+            path,
+            text,
+        )))
         data = None
 
     return data
diff --git a/rophako/utils.py b/rophako/utils.py
index e74a808..82b0472 100644
--- a/rophako/utils.py
+++ b/rophako/utils.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
-from flask import g, session, request, render_template, flash, redirect, url_for
+from flask import (g, session, request, render_template, flash, redirect,
+    url_for, current_app)
 from functools import wraps
 import codecs
 import uuid
@@ -12,6 +13,7 @@ import smtplib
 import markdown
 import json
 import urlparse
+import traceback
 
 from rophako.log import logger
 from rophako.settings import Config
@@ -192,6 +194,61 @@ def send_email(to, subject, message, sender=None, reply_to=None):
             server.quit()
 
 
+def handle_exception(error):
+    """Send an e-mail to the site admin when an exception occurs."""
+    if current_app.config.get("DEBUG"):
+        print traceback.format_exc()
+        raise
+
+    import rophako.jsondb as JsonDB
+
+    # Don't spam too many e-mails in a short time frame.
+    cache = JsonDB.get_cache("exception_catcher")
+    if cache:
+        last_exception = int(cache)
+        if int(time.time()) - last_exception < 120:
+            # Only one e-mail per 2 minutes, minimum
+            logger.error("RAPID EXCEPTIONS, DROPPING")
+            return
+    JsonDB.set_cache("exception_catcher", int(time.time()))
+
+    username = "anonymous"
+    try:
+        if "username" in g.info["session"]:
+            username = g.info["session"]["username"]
+    except:
+        pass
+
+    # Get the timestamp.
+    timestamp = time.ctime(time.time())
+
+    # Exception's traceback.
+    error = str(error.__class__.__name__) + ": " + str(error)
+    stacktrace = error + "\n\n" \
+        + "==== Start Traceback ====\n" \
+        + traceback.format_exc() \
+        + "==== End Traceback ====\n"
+
+    # Construct the subject and message
+    subject = "Internal Server Error on {} - {} - {}".format(
+        Config.site.site_name,
+        username,
+        timestamp,
+    )
+    message = "{} has experienced an exception on the route: {}".format(
+        username,
+        request.path,
+    )
+    message += "\n\n" + stacktrace
+
+    # Send the e-mail.
+    send_email(
+        to=Config.site.notify_address,
+        subject=subject,
+        message=message,
+    )
+
+
 def generate_csrf_token():
     """Generator for CSRF tokens."""
     if "_csrf" not in session:
diff --git a/rophako/www/errors/500.html b/rophako/www/errors/500.html
new file mode 100644
index 0000000..b1b7c27
--- /dev/null
+++ b/rophako/www/errors/500.html
@@ -0,0 +1,10 @@
+{% extends "layout.html" %}
+{% block title %}Internal Server Error{% endblock %}
+{% block content %}
+
+<h1>Internal Server Error</h1>
+
+This website has experienced an error. The site admin has been sent an e-mail
+about this. Please retry your request sometime later.
+
+{% endblock %}
diff --git a/runserver.py b/runserver.py
index ea9f846..8d37d05 100644
--- a/runserver.py
+++ b/runserver.py
@@ -25,12 +25,17 @@ parser.add_argument(
     type=str,
     help="SSL certificate file.",
 )
+parser.add_argument(
+    "--production",
+    help="Turns off debug mode, runs as if in production.",
+    action="store_true",
+)
 args = parser.parse_args()
 
 if __name__ == '__main__':
     flask_options = dict(
         host='0.0.0.0',
-        debug=True,
+        debug=not args.production,
         port=args.port,
         threaded=True,
     )