因为我的docker镜像中安装了rabbitmq server
apt-get install -y -q --allow-unauthenticated rabbitmq-server
在build过程中会报错：
Not creating home directory `/var/lib/rabbitmq’.
invoke-rc.d: could not determine current runlevel
invoke-rc.d: policy-rc.d denied execution of start.
Processing triggers for libc-bin (2.27-3ubuntu1) …
这是因为这个安装命令同时会启动rabbitmq server,build 出镜像是静态的，当然无法启动。要启动需要在放到docker的entrypoint脚本中。
Each of your commands that you execute creates a container. The docker build command (e.g. RUN) will then be executed in that container and then saved as an image.
importANT running processes terminate when the image is saved. Background/daemon processes do not work with docker - that is by design That means avoid if possible to run commands like “service start” in your dockerfile (since that will not persist to the next layer / command.
具体原因这篇文章中讲得很清楚：
https://stackoverflow.com/questions/58480368/is-there-a-way-to-set-the-run-level-on-the-docker
