fix(limit_conn): do not use the http variable in stream mode (#9816)

apisix/plugins/limit-conn/init.lua

@@ -16,6 +16,7 @@
 --
 local limit_conn_new = require("resty.limit.conn").new
 local core = require("apisix.core")
+local is_http = ngx.config.subsystem == "http"
 local sleep = core.sleep
 local shdict_name = "plugin-limit-conn"
 if ngx.config.subsystem == "stream" then
@@ -115,11 +116,13 @@ function _M.decrease(conf, ctx)
         local use_delay =  limit_conn[i + 3]
 
         local latency
-        if not use_delay then
-            if ctx.proxy_passed then
-                latency = ctx.var.upstream_response_time
-            else
-                latency = ctx.var.request_time - delay
+        if is_http then
+            if not use_delay then
+                if ctx.proxy_passed then
+                    latency = ctx.var.upstream_response_time
+                else
+                    latency = ctx.var.request_time - delay
+                end
             end
         end
         core.log.debug("request latency is ", latency) -- for test

t/stream-plugin/limit-conn2.t

@@ -0,0 +1,134 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+use t::APISIX;
+
+my $nginx_binary = $ENV{'TEST_NGINX_BINARY'} || 'nginx';
+my $version = eval { `$nginx_binary -V 2>&1` };
+
+if ($version !~ m/\/apisix-nginx-module/) {
+    plan(skip_all => "apisix-nginx-module not installed");
+} else {
+    plan('no_plan');
+}
+
+$ENV{TEST_NGINX_REDIS_PORT} ||= 1985;
+
+add_block_preprocessor(sub {
+    my ($block) = @_;
+
+    if (!$block->extra_yaml_config) {
+        my $extra_yaml_config = <<_EOC_;
+xrpc:
+  protocols:
+    - name: redis
+_EOC_
+        $block->set_value("extra_yaml_config", $extra_yaml_config);
+    }
+
+
+    if (!defined $block->request) {
+        $block->set_value("request", "GET /t");
+    }
+
+    $block;
+});
+
+worker_connections(1024);
+run_tests;
+
+__DATA__
+
+=== TEST 1: create a stream router with limit-conn
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/stream_routes/1',
+                 ngx.HTTP_PUT,
+                 [[{
+                    "plugins": {
+                        "limit-conn": {
+                            "conn": 2,
+                            "burst": 1,
+                            "default_conn_delay": 0.1,
+                            "key": "$remote_port $server_addr",
+                            "key_type": "var_combination"
+                        }
+                    },
+                    "upstream": {
+                        "type": "none",
+                        "nodes": {
+                          "127.0.0.1:6379": 1
+                        }
+                      },
+                      "protocol": {
+                        "name": "redis"
+                      }
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 2: access the redis via proxy
+--- config
+    location /t {
+        content_by_lua_block {
+            local redis = require "resty.redis"
+            local red = redis:new()
+
+            local ok, err = red:connect("127.0.0.1", $TEST_NGINX_REDIS_PORT)
+            if not ok then
+                ngx.say("failed to connect: ", err)
+                return
+            end
+
+            local res, err = red:hmset("animals", "dog", "bark", "cat", "meow")
+            if not res then
+                ngx.say("failed to set animals: ", err)
+                return
+            end
+            ngx.say("hmset animals: ", res)
+
+            local res, err = red:hmget("animals", "dog", "cat")
+            if not res then
+                ngx.say("failed to get animals: ", err)
+                return
+            end
+            ngx.say("hmget animals: ", res)
+
+            ok, err = red:close()
+            if not ok then
+                ngx.say("failed to close: ", err)
+                return
+            end
+        }
+    }
+--- response_body
+hmset animals: OK
+hmget animals: barkmeow
+--- no_error_log
+attempt to perform arithmetic on field 'request_time'
+--- stream_conf_enable