fix(incremental sync): fix cache_key handling for select_by_cache_key

kong/db/declarative/import.lua

@@ -315,6 +315,18 @@ local function _set_entity_for_txn(t, entity_name, item, options, is_delete)
   if schema.cache_key then
     local cache_key = dao:cache_key(item)
 
+    -- [[ TODO:
+    -- This part is used to add additional value of cache_key, we need to
+    -- make this code more stable, currently fixing is_consumer_in_group()
+    -- Note is_consumer_in_group() could not pass ws_id to construct cache_key,
+    -- so we need to set item.ws_id to nil firstly.
+    local ws_id = item.ws_id
+    item.ws_id = nil
+    cache_key = dao:cache_key(item)
+    t:set(cache_key, itm_value)
+    item.ws_id = ws_id
+    -- ]]
+
     for _, wid in ipairs {ws_id, GLOBAL_WORKSPACE_TAG} do
       local key = unique_field_key(entity_name, wid, "cache_key", cache_key)
 

kong/db/strategies/off/init.lua

@@ -208,6 +208,15 @@ local function select_by_field(self, field, value, options)
     _, value = next(value)
   end
 
+  -- [[ TODO:
+  -- This part is used to add additional value of cache_key, we need to
+  -- make this code more stable, currently fixing is_consumer_in_group()
+  if field == "cache_key" then
+    local cache_key = value
+    return select_by_key(schema, cache_key, false)
+  end
+  -- ]]
+
   local ws_id = workspace_id(schema, options)
 
   local key