Add sentry exception monitoring.

config.py

@@ -32,7 +32,7 @@ def logs_init_builder(level=logging.DEBUG,
 # values are set to the frontend, DO NOT PLACE ANY SECRETS OR KEYS in this list.
 CLIENT_WHITELIST = ['SERVER_HOSTNAME', 'PREFERRED_URL_SCHEME', 'GITHUB_CLIENT_ID',
                     'GITHUB_LOGIN_CLIENT_ID', 'MIXPANEL_KEY', 'STRIPE_PUBLISHABLE_KEY',
-                    'ENTERPRISE_LOGO_URL']
+                    'ENTERPRISE_LOGO_URL', 'SENTRY_PUBLIC_DSN']
 
 
 def getFrontendVisibleConfig(config_dict):
@@ -102,6 +102,11 @@ class DefaultConfig(object):
   # Analytics
   ANALYTICS_TYPE = "FakeAnalytics"
 
+  # Exception logging
+  EXCEPTION_LOG_TYPE = 'FakeSentry'
+  SENTRY_DSN = None
+  SENTRY_PUBLIC_DSN = None
+
   # Github Config
   GITHUB_TOKEN_URL = 'https://github.com/login/oauth/access_token'
   GITHUB_USER_URL = 'https://api.github.com/user'