Got grpc Connection timed out

[root@iZwz90pj2xzabk2hl96aetZ ~]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:2049            0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:42437           0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:5355            0.0.0.0:*               LISTEN      482/systemd-resolve 
tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      1/systemd           
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      59791/nginx: worker 
tcp        0      0 0.0.0.0:20048           0.0.0.0:*               LISTEN      944/rpc.mountd      
tcp        0      0 0.0.0.0:58545           0.0.0.0:*               LISTEN      943/rpc.statd       
tcp        0      0 0.0.0.0:8788            0.0.0.0:*               LISTEN      3404566/docker-prox 
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      3378454/sshd        
tcp6       0      0 :::42431                :::*                    LISTEN      -                   
tcp6       0      0 :::2049                 :::*                    LISTEN      -                   
tcp6       0      0 :::5355                 :::*                    LISTEN      482/systemd-resolve 
tcp6       0      0 :::111                  :::*                    LISTEN      1/systemd           
tcp6       0      0 :::20048                :::*                    LISTEN      944/rpc.mountd      
tcp6       0      0 :::58739                :::*                    LISTEN      943/rpc.statd       
tcp6       0      0 :::8788                 :::*                    LISTEN      3404570/docker-prox 
[root@iZwz90pj2xzabk2hl96aetZ ~]# docker container ls
CONTAINER ID   IMAGE             COMMAND                  CREATED         STATUS         PORTS                                       NAMES
e701274f3b24   wechaty/wechaty   "/wechaty/bin/entryp…"   2 minutes ago   Up 2 minutes   0.0.0.0:8788->8788/tcp, :::8788->8788/tcp   thirsty_pasteur

io.grpc.StatusRuntimeException: UNAVAILABLE: io exception
    at io.grpc.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:244) ~[grpc-stub-1.29.0.jar:1.29.0]
    at io.grpc.stub.ClientCalls.getUnchecked(ClientCalls.java:225) ~[grpc-stub-1.29.0.jar:1.29.0]
    at io.grpc.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:142) ~[grpc-stub-1.29.0.jar:1.29.0]
    at io.github.wechaty.grpc.PuppetGrpc$PuppetBlockingStub.start(PuppetGrpc.java:2744) ~[grpc-0.16.1.jar:?]
    at io.github.wechaty.grpc.GrpcPuppet.start(GrpcPuppet.kt:78) [wechaty-puppet-hostie-0.1.5-20200719.133816-1.jar:?]
    at io.github.wechaty.Wechaty.start(Wechaty.kt:52) [wechaty-0.1.5-20200719.133942-1.jar:?]
    at io.github.wechaty.DingDongBot.main(DingDongBot.java:50) [classes/:?]
Caused by: io.grpc.netty.shaded.io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information: /120.76.139.69:8788
Caused by: java.net.ConnectException: Connection timed out: no further information
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) ~[?:1.8.0_102]
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) ~[?:1.8.0_102]
    at io.grpc.netty.shaded.io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:330) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:334) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:702) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at io.grpc.netty.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[grpc-netty-shaded-1.29.0.jar:1.29.0]
    at java.lang.Thread.run(Thread.java:745) ~[?:1.8.0_102]
16:36:32.242 [main]DEBUG io.github.wechaty.eventEmitter.EventEmitter-[43]  - this eventName:START has no listener

wechaty / java-wechaty-getting-started

Got grpc Connection timed out #36