New command to unlock mail as a failsafe

django_mailer/management/commands/unlock_mail.py

@@ -0,0 +1,32 @@
+import datetime
+import os
+import time
+
+from django.conf import settings
+from django.contrib.sites.models import Site
+from django.core.mail import mail_admins
+from django.core.management.base import NoArgsCommand
+
+from django_mailer.engine import LOCK_PATH
+
+
+class Command(NoArgsCommand):
+    """
+    See logic at https://github.com/ptone/django-mailer-2/blob/master/django_mailer/engine.py
+    it's possible for the mailer to get hung up and not recover, so let's check this file
+    every X minutes to make sure it's not very old.
+    """
+    help = "Clean out cover images that never made it past the temp folder"
+
+    def handle_noargs(self, **options):
+        if not os.path.exists(LOCK_PATH):
+            return
+        threshold = time.mktime(
+            (datetime.datetime.now() - datetime.timedelta(minutes=4)).timetuple())
+        if os.path.getmtime(LOCK_PATH) < threshold:
+            try:
+                os.unlink(LOCK_PATH)
+            except Exception:
+                site = Site.objects.get_current()
+                mail_admins("Mail sending is locked on %s" % site,
+                            "Mail sending on this server appears to be stuck")