fix(ai-rate-limiting): not allowed to limit to a single instance

Author: shreemaan-abhishek

apisix/plugins/ai-rate-limiting.lua

@@ -47,7 +47,8 @@ local schema = {
         },
         instances = {
             type = "array",
-            items = instance_limit_schema
+            items = instance_limit_schema,
+            minItems = 1,
         },
         rejected_code = {
             type = "integer", minimum = 200, maximum = 599, default = 503
@@ -56,7 +57,18 @@ local schema = {
             type = "string", minLength = 1
         },
     },
-    required = {"limit", "time_window"},
+    dependencies = {
+        limit = {"time_window"},
+        time_window = {"limit"}
+    },
+    anyOf = {
+        {
+            required = {"limit", "time_window"}
+        },
+        {
+            required = {"instances"}
+        }
+    }
 }
 
 local _M = {
@@ -112,6 +124,10 @@ end
 local function fetch_limit_conf_kvs(conf)
     local mt = {
         __index = function(t, k)
+            if not conf.limit then
+                return nil
+            end
+
             local limit_conf = transform_limit_conf(conf, nil, k)
             t[k] = limit_conf
             return limit_conf
@@ -134,6 +150,9 @@ function _M.access(conf, ctx)
 
     local limit_conf_kvs = limit_conf_cache(conf, nil, fetch_limit_conf_kvs, conf)
     local limit_conf = limit_conf_kvs[ai_instance_name]
+    if not limit_conf then
+        return
+    end
     local code, msg = limit_count.rate_limit(limit_conf, ctx, plugin_name, 1, true)
     ctx.ai_rate_limiting = code and true or false
     return code, msg
@@ -164,6 +183,10 @@ function _M.check_instance_status(conf, ctx, instance_name)
 
     local limit_conf_kvs = limit_conf_cache(conf, nil, fetch_limit_conf_kvs, conf)
     local limit_conf = limit_conf_kvs[instance_name]
+    if not limit_conf then
+        return true
+    end
+
     local code, _ = limit_count.rate_limit(limit_conf, ctx, plugin_name, 1, true)
     if code then
         core.log.info("rate limit for instance: ", instance_name, " code: ", code)
@@ -202,7 +225,9 @@ function _M.log(conf, ctx)
 
     local limit_conf_kvs = limit_conf_cache(conf, nil, fetch_limit_conf_kvs, conf)
     local limit_conf = limit_conf_kvs[instance_name]
-    limit_count.rate_limit(limit_conf, ctx, plugin_name, used_tokens)
+    if limit_conf then
+        limit_count.rate_limit(limit_conf, ctx, plugin_name, used_tokens)
+    end
 end