dockerfile里面的expose 指定的端口作用？

Question

dockerfile里面的expose 指定的端口作用？
只是为了后期方便查看这个image会启动那些端口吗？如果不写是不是后期照样可以启动？

Answer 1

麦兜搞IT 2018-09-21 09:31:28

您好，不写也是可以的，您可以把它看成是一种文档功能，让Dockerfile的作者和这个image的使用者知道可以暴露哪些端口。下面是docker的官方文档定义

The EXPOSE instruction does not actually publish the port. It functions as a type of documentation between the person who builds the image and the person who runs the container, about which ports are intended to be published. To actually publish the port when running the container, use the -p flag on docker run to publish and map one or more ports, or the -P flag to publish all exposed ports and map them to high-order ports.