docker镜像可以使用来自主机的可执行文件吗？

Question

I have several Java services, each packaged as a separate jar file. I plan to package the as docker images. Do I need to bundle the Java runtime on each image, or can I rely on the fact the host (that will run the image) already has the Java runtime?

Answer 1

You could use a volume to mount the Java runtime from the host into the container, but this makes the container less portable (as Andrew Fox points out).

If instead you use a common base image such as java:8-jre for your containers, the image will be shared between containers meaning that there is only one copy on disk (not one copy per container).

Not that in both cases, you will still have multiple JVMs running, one for each container.

Answer 2

The idea of docker is to make your setup portable so if you don't put in the Java runtime you can't guarantee it will work properly on a destination system. I don't believe docker can access host executables unless there is a special whitelist setting somewhere but in my experience no it can't.