Add manage command run_with_lock

distributedlock/management/commands/run_with_lock.py

@@ -0,0 +1,36 @@
+from django.core.management import ManagementUtility
+from django.core.management.base import BaseCommand, CommandError
+from distributedlock import distributedlock, LockNotAcquiredError
+import types
+
+
+class Command(BaseCommand):
+    """
+    Dynamically invokes the command, patching its handle to use distributedlock and perfectly forwards arguments
+    usage example:
+    manage run_with_lock update_calendars --ignore-past
+    """
+
+    def handle(self, *args, **options):
+        pass
+
+    help = 'A wrapper command that runs a manage command with a distributed lock.'
+
+    def run_from_argv(self, argv):
+        try:
+            command_name = argv[2]
+            argv.pop(1)
+            utility = ManagementUtility(argv)
+            command_class = utility.fetch_command(command_name)
+            handle = command_class.handle
+
+            def locking_handle(self, *args, **options):
+                with distributedlock(command_name):
+                    handle(self, *args, **options)
+
+            command_class.handle = types.MethodType(locking_handle, command_class)
+            command_class.run_from_argv(utility.argv)
+        except IndexError:
+            raise CommandError('Missing arguments')
+        except LockNotAcquiredError:
+            raise CommandError('%s command is already locked' % command_name)