Netstat无法显示Docker暴露的端口

Question

由于某种原因，netstat没有列出docker暴露的端口。根据这里建议，我使用了EXPOSE来展示8080和5050两个端口。但是，它们都无法从主机上看到。

Dockerfile

...

FROM openjdk:11-jre-slim

COPY --from=build /usr/src/app/api/target/track-metadata-api-*.jar /app/track-metadata-api.jar

WORKDIR /app

EXPOSE 8080 5050

CMD java -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5050 -jar track-metadata-api.jar

docker ps

$ docker ps
CONTAINER ID        IMAGE                           COMMAND                  CREATED             STATUS              PORTS                                            NAMES
a6d3381a992d        track-metadata_track-metadata   "/bin/sh -c 'java -a…"   7 minutes ago       Up 7 minutes        0.0.0.0:5050->5050/tcp, 0.0.0.0:8080->8080/tcp   track-metadata_track-metadata_1

netstat & curl

$ sudo netstat --all | grep 8080 # returns nothing
$ curl http://localhost:8080/v1/track-metadata/filtered
[{"authorName":"AC/DC","duration":208,"id":1,"tags":"#rock","trackName":"Highway to Hell"},{"authorName":"Sum41","duration":209,"id":2,"tags":"#rock","trackName":"War"},{"authorName":"Ziggy Marley","duration":220,"id":3,"tags":"#ragge","trackName":"Beach in Hawaii"}]

Docker和Ubuntu版本

$ docker --version 
Docker version 18.06.1-ce, build e68fc7a
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.10
Release:    18.10

代号：cosmic

- Matjaž

Answer 1

问题出在netstat命令上，添加-anp标志后，端口被列出。

$ sudo netstat -anp | grep 8080
tcp6       0      0 :::8080                 :::*                    LISTEN      16341/docker-proxy

- Matjaž

Answer 2

为了暴露端口，您必须在使用docker run运行镜像时传递-P（将所有公开的端口发布到随机端口）标志，或者选择传递-p标志并指定特定端口，详见此处。

- Marcus

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端口已经暴露，请查看 docker ps 的输出。 - Matjaž