Mailman: don't report useless exceptions in Django via email

roles/mailman/files/django_fedora.py

@@ -0,0 +1,17 @@
+from django.core.exceptions import DisallowedHost
+from django.http import UnreadablePostError
+from pylibmc import Error as MemcachedError
+
+EXCLUDED = (
+    DisallowedHost,
+    UnreadablePostError,
+    MemcachedError,
+)
+
+def exclude_useless_errors(record):
+    if record.exc_info:
+        exc_type, exc_value = record.exc_info[:2]
+        for excluded_class in EXCLUDED:
+            if isinstance(exc_value, EXCLUDED):
+                return False
+    return True

roles/mailman/tasks/main.yml

@@ -5,6 +5,7 @@
 
 #
 # SELinux
+# TODO: switch to the sefcontext module when we update Ansible to 2.2+
 #
 - name: install semanage
   yum: pkg=policycoreutils-python state=present
@@ -266,6 +267,16 @@
   - config
   - mailman
 
+- name: install the django_fedora module
+  copy: src=django_fedora.py
+        dest="{{ mailman_webui_confdir }}/django_fedora.py"
+        owner=root group=root mode=0644
+  tags:
+  - config
+  - mailman
+  notify:
+    - reload apache
+
 - name: install the hyperkitty urls file
   copy: src=urls.py
         dest="{{ mailman_webui_confdir }}/urls.py"

roles/mailman/templates/settings.py.j2

@@ -6,6 +6,8 @@ Django settings for HyperKitty + Postorius
 import os
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 
+import django_fedora
+
 # SECURITY WARNING: keep the secret key used in production secret!
 SECRET_KEY = '{{ mailman_hyperkitty_cookie_key }}'
 
@@ -29,7 +31,7 @@ ALLOWED_HOSTS = [
     ".fedoraproject.org",
     "localhost", # Archiving API from Mailman
     "127.0.0.1", # HAProxy ping
-    "mailman01", # Varnish ping on STG
+    "{{ ansible_hostname }}", # Varnish ping
 ]
 
 # Mailman API credentials
@@ -322,12 +324,16 @@ LOGGING = {
     'filters': {
         'require_debug_false': {
             '()': 'django.utils.log.RequireDebugFalse'
+        },
+        'exclude_useless_errors': {
+            '()': 'django.utils.log.CallbackFilter',
+            'callback': django_fedora.exclude_useless_errors,
         }
     },
     'handlers': {
         'mail_admins': {
             'level': 'ERROR',
-            'filters': ['require_debug_false'],
+            'filters': ['require_debug_false', 'exclude_useless_errors'],
             'class': 'django.utils.log.AdminEmailHandler'
         },
         'file':{
@@ -340,7 +346,12 @@ LOGGING = {
     },
     'loggers': {
         'django.request': {
-            'handlers': ['mail_admins', 'file'],
+            'handlers': [
+                'file',
+                {% if env == 'prod' %}
+                'mail_admins',
+                {% endif %}
+            ],
             'level': 'DEBUG',
             'propagate': True,
         },