Issue description

By using the mqtt_proxy plugin it isn't possible to make up a connection to the mqtt broker, in this case mosquitto. All done with docker compose.

Environment

• apisix version (cmd: apisix version): 2.11.0
• OS (cmd: uname -a): Darwin Kernel Version 20.6.0

Steps to reproduce

1. create docker environment based on APISIX-docker with additional mosquitto service
2. configure stream_proxy in config.yaml
3. create stream_routes according to the example provided in the documentation

Actual result

mqtt pub -t test -m "Hello" -h 127.0.0.1 -p 1883 creates a topic test with message Hello.
mqtt pub -t test -m "Hello" -h 127.0.0.1 -p 9100 does nothing the mqtt client is running into a timeout

Error log

2021/12/14 09:16:03 [warn] 46#46: 4 [lua] plugin.lua:172: load(): new plugins: {"zipkin":true,"openid-connect":true,"key-auth":true,"ip-restriction":true,"uri-blocker":true,"batch-requests":true,"fault-injection":true,"basic-auth":true,"request-validation":true,"grpc-transcode":true,"example-plugin":true,"kafka-logger":true,"ldap-auth":true,"wolf-rbac":true,"limit-req":true,"consumer-restriction":true,"limit-count":true,"tcp-logger":true,"serverless-post-function":true,"serverless-pre-function":true,"echo":true,"client-control":true,"ext-plugin-post-req":true,"sls-logger":true,"azure-functions":true,"udp-logger":true,"gzip":true,"syslog":true,"http-logger":true,"proxy-cache":true,"skywalking-logger":true,"api-breaker":true,"authz-casbin":true,"jwt-auth":true,"server-info":true,"traffic-split":true,"real-ip":true,"proxy-mirror":true,"response-rewrite":true,"limit-conn":true,"redirect":true,"cors":true,"ua-restriction":true,"datadog":true,"prometheus":true,"ext-plugin-pre-req":true,"authz-keycloak":true,"proxy-rewrite":true,"hmac-auth":true,"referer-restriction":true,"request-id":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 48#48: 3 [lua] plugin.lua:172: load(): new plugins: {"zipkin":true,"openid-connect":true,"key-auth":true,"ip-restriction":true,"uri-blocker":true,"batch-requests":true,"fault-injection":true,"basic-auth":true,"request-validation":true,"grpc-transcode":true,"example-plugin":true,"kafka-logger":true,"ldap-auth":true,"wolf-rbac":true,"limit-req":true,"consumer-restriction":true,"limit-count":true,"tcp-logger":true,"serverless-post-function":true,"serverless-pre-function":true,"echo":true,"client-control":true,"ext-plugin-post-req":true,"sls-logger":true,"azure-functions":true,"udp-logger":true,"gzip":true,"syslog":true,"http-logger":true,"proxy-cache":true,"skywalking-logger":true,"api-breaker":true,"authz-casbin":true,"jwt-auth":true,"server-info":true,"traffic-split":true,"real-ip":true,"proxy-mirror":true,"response-rewrite":true,"limit-conn":true,"redirect":true,"cors":true,"ua-restriction":true,"datadog":true,"prometheus":true,"ext-plugin-pre-req":true,"authz-keycloak":true,"proxy-rewrite":true,"hmac-auth":true,"referer-restriction":true,"request-id":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 49#49: 1 [lua] plugin.lua:172: load(): new plugins: {"zipkin":true,"openid-connect":true,"key-auth":true,"ip-restriction":true,"uri-blocker":true,"batch-requests":true,"fault-injection":true,"basic-auth":true,"request-validation":true,"grpc-transcode":true,"example-plugin":true,"kafka-logger":true,"ldap-auth":true,"wolf-rbac":true,"limit-req":true,"consumer-restriction":true,"limit-count":true,"tcp-logger":true,"serverless-post-function":true,"serverless-pre-function":true,"echo":true,"client-control":true,"ext-plugin-post-req":true,"sls-logger":true,"azure-functions":true,"udp-logger":true,"gzip":true,"syslog":true,"http-logger":true,"proxy-cache":true,"skywalking-logger":true,"api-breaker":true,"authz-casbin":true,"jwt-auth":true,"server-info":true,"traffic-split":true,"real-ip":true,"proxy-mirror":true,"response-rewrite":true,"limit-conn":true,"redirect":true,"cors":true,"ua-restriction":true,"datadog":true,"prometheus":true,"ext-plugin-pre-req":true,"authz-keycloak":true,"proxy-rewrite":true,"hmac-auth":true,"referer-restriction":true,"request-id":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 47#47: 2 [lua] plugin.lua:172: load(): new plugins: {"zipkin":true,"openid-connect":true,"key-auth":true,"ip-restriction":true,"uri-blocker":true,"batch-requests":true,"fault-injection":true,"basic-auth":true,"request-validation":true,"grpc-transcode":true,"example-plugin":true,"kafka-logger":true,"ldap-auth":true,"wolf-rbac":true,"limit-req":true,"consumer-restriction":true,"limit-count":true,"tcp-logger":true,"serverless-post-function":true,"serverless-pre-function":true,"echo":true,"client-control":true,"ext-plugin-post-req":true,"sls-logger":true,"azure-functions":true,"udp-logger":true,"gzip":true,"syslog":true,"http-logger":true,"proxy-cache":true,"skywalking-logger":true,"api-breaker":true,"authz-casbin":true,"jwt-auth":true,"server-info":true,"traffic-split":true,"real-ip":true,"proxy-mirror":true,"response-rewrite":true,"limit-conn":true,"redirect":true,"cors":true,"ua-restriction":true,"datadog":true,"prometheus":true,"ext-plugin-pre-req":true,"authz-keycloak":true,"proxy-rewrite":true,"hmac-auth":true,"referer-restriction":true,"request-id":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 52#52: 5 [lua] plugin.lua:172: load(): new plugins: {"zipkin":true,"openid-connect":true,"key-auth":true,"ip-restriction":true,"uri-blocker":true,"batch-requests":true,"fault-injection":true,"basic-auth":true,"request-validation":true,"grpc-transcode":true,"example-plugin":true,"kafka-logger":true,"ldap-auth":true,"wolf-rbac":true,"limit-req":true,"consumer-restriction":true,"limit-count":true,"tcp-logger":true,"serverless-post-function":true,"serverless-pre-function":true,"echo":true,"client-control":true,"ext-plugin-post-req":true,"sls-logger":true,"azure-functions":true,"udp-logger":true,"gzip":true,"syslog":true,"http-logger":true,"proxy-cache":true,"skywalking-logger":true,"api-breaker":true,"authz-casbin":true,"jwt-auth":true,"server-info":true,"traffic-split":true,"real-ip":true,"proxy-mirror":true,"response-rewrite":true,"limit-conn":true,"redirect":true,"cors":true,"ua-restriction":true,"datadog":true,"prometheus":true,"ext-plugin-pre-req":true,"authz-keycloak":true,"proxy-rewrite":true,"hmac-auth":true,"referer-restriction":true,"request-id":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 49#49: 1 [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 47#47: 2 [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 48#48: 3 [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 46#46: 4 [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 52#52: 5 [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 47#47: 6 stream [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 48#48: 7 stream [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 49#49: 8 stream [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 46#46: 9 stream [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua
2021/12/14 09:16:03 [warn] 52#52: 10 stream [lua] plugin.lua:222: load_stream(): new plugins: {"ip-restriction":true,"mqtt-proxy":true,"limit-conn":true}, context: init_worker_by_lua

Expected result

The creation of the topic test with the message Hello