错误：
docker启动nacos
docker run --name nacos -e MODE=standalone -p 8848:8848 -d nacos/nacos-server:latest运行springboot项目报错
Caused by: com.alibaba.nacos.shaded.io.grpc.StatusRuntimeException: UNAVAILABLE: io exception
at com.alibaba.nacos.shaded.io.grpc.Status.asRuntimeException(Status.java:533) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.stub.ClientCalls$UnaryStreamToFuture.onClose(ClientCalls.java:515) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:426) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.ClientCallImpl.access$500(ClientCallImpl.java:66) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:689) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$900(ClientCallImpl.java:577) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:751) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:740) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37) ~[nacos-client-2.2.1-RC.jar:na]
at com.alibaba.nacos.shaded.io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123) ~[nacos-client-2.2.1-RC.jar:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]
Caused by: com.alibaba.nacos.shaded.io.grpc.netty.shaded.io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information: /127.0.0.1:9848
Caused by: java.net.ConnectException: Connection refused: no further information
at java.base/sun.nio.ch.Net.pollConnect(Native Method) ~[na:na]
at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:672) ~[na:na]原因：nacos通信需要三个端口：原端口、原端口+1000、原端口+1001偏移量。
所以需要开启8848、9848、9849三个端口
解决：
只在服务器防火墙开放这三个端口是没用的，需要在docker容器启动时也把这三个端口映射出去，所以启动命令应该是这样的：
docker run --name nacos -e MODE=standalone -p 8848:8848 -p 9848:9848 -p 9849:9849 -d nacos/nacos-server:latest