Add support for multiple celery queues

Close #163

AUTHORS

@@ -8,3 +8,4 @@ The following people have contributed to django-health-check:
 - Johannes Hoppe
 - Aleksi Häkli
 - Mark Speedy
+- Marcin Górny

health_check/contrib/celery/apps.py

@@ -1,3 +1,4 @@
+from celery import current_app
 from django.apps import AppConfig
 
 from health_check.plugins import plugin_dir
@@ -8,4 +9,9 @@ class HealthCheckConfig(AppConfig):
 
     def ready(self):
         from .backends import CeleryHealthCheck
-        plugin_dir.register(CeleryHealthCheck)
+
+        for queue in current_app.amqp.queues:
+            celery_class_name = 'CeleryHealthCheck' + queue.title()
+
+            celery_class = type(celery_class_name, (CeleryHealthCheck,), {'queue': queue})
+            plugin_dir.register(celery_class)

health_check/contrib/celery/backends.py

@@ -15,7 +15,8 @@ def check_status(self):
         try:
             result = add.apply_async(
                 args=[4, 4],
-                expires=timeout
+                expires=timeout,
+                queue=self.queue
             )
             result.get(timeout=timeout)
             if result.result != 8:

tests/test_autodiscover.py

@@ -1,13 +1,22 @@
+from celery import current_app
 from django.conf import settings
 
+from health_check.contrib.celery.backends import CeleryHealthCheck
 from health_check.plugins import plugin_dir
 
 
 class TestAutoDiscover:
     def test_autodiscover(self):
         health_check_plugins = list(filter(
-            lambda x: 'health_check.' in x,
+            lambda x: 'health_check.' in x and 'celery' not in x,
             settings.INSTALLED_APPS
         ))
 
-        assert len(plugin_dir._registry) == len(health_check_plugins)
+        non_celery_plugins = [x for x in plugin_dir._registry if not issubclass(x[0], CeleryHealthCheck)]
+
+        # The number of installed apps excluding celery should equal to all plugins except celery
+        assert len(non_celery_plugins) == len(health_check_plugins)
+
+    def test_discover_celery_queues(self):
+        celery_plugins = [x for x in plugin_dir._registry if issubclass(x[0], CeleryHealthCheck)]
+        assert len(celery_plugins) == len(current_app.amqp.queues)

tests/testapp/__init__.py

@@ -0,0 +1,3 @@
+from .celery import app
+
+__all__ = ['app']

tests/testapp/celery.py

@@ -0,0 +1,4 @@
+from celery import Celery
+
+app = Celery('testapp')
+app.config_from_object('django.conf:settings', namespace='CELERY')

tests/testapp/settings.py

@@ -53,3 +53,8 @@
 SECRET_KEY = uuid.uuid4().hex
 
 USE_L10N = True
+
+CELERY_TASK_QUEUES = {
+    'default': {},
+    'queue2': {}
+}