Revert to apline:3.11 to stay on Python 3.7 (3.8 has issues with channels)

api/Dockerfile

-FROM alpine:3.11
+FROM alpine:3.10
 
 RUN \
     echo 'installing dependencies' && \

api/config/settings/common.py

@@ -544,7 +544,7 @@ CHANNEL_LAYERS = {
 }
 
 CACHES["default"]["OPTIONS"] = {
-    "CLIENT_CLASS": "django_redis.client.DefaultClient",
+    "CLIENT_CLASS": "funkwhale_api.common.cache.RedisClient",
     "IGNORE_EXCEPTIONS": True,  # mimics memcache behavior.
     # http://niwinz.github.io/django-redis/latest/#_memcached_exceptions_behavior
 }

api/funkwhale_api/common/cache.py

+import logging
+
+from django_redis.client import default
+
+logger = logging.getLogger(__name__)
+
+
+class RedisClient(default.DefaultClient):
+    def get(self, key, default=None, version=None, client=None):
+        try:
+            return super().get(key, default=None, version=None, client=None)
+        except ValueError as e:
+            if "unsupported pickle protocol" in str(e):
+                # pickle deserialization error
+                logger.warn("Error while deserializing pickle value from cache")
+                return default
+            else:
+                raise
+
+    def get_many(self, *args, **kwargs):
+        try:
+            return super().get_many(*args, **kwargs)
+        except ValueError as e:
+            if "unsupported pickle protocol" in str(e):
+                # pickle deserialization error
+                logger.warn("Error while deserializing pickle value from cache")
+                return {}
+            else:
+                raise

api/funkwhale_api/common/channels.py

@@ -8,6 +8,7 @@ from django.core.serializers.json import DjangoJSONEncoder
 logger = logging.getLogger(__name__)
 channel_layer = get_channel_layer()
 group_add = async_to_sync(channel_layer.group_add)
+group_discard = async_to_sync(channel_layer.group_discard)
 
 
 def group_send(group, event):

api/funkwhale_api/common/consumers.py

@@ -14,7 +14,11 @@ class JsonAuthConsumer(JsonWebsocketConsumer):
 
     def accept(self):
         super().accept()
-        for group in self.groups:
-            channels.group_add(group, self.channel_name)
-        for group in self.scope["user"].get_channels_groups():
+        groups = self.scope["user"].get_channels_groups() + self.groups
+        for group in groups:
             channels.group_add(group, self.channel_name)
+
+    def disconnect(self, close_code):
+        groups = self.scope["user"].get_channels_groups() + self.groups
+        for group in groups:
+            channels.group_discard(group, self.channel_name)