Let's say my own Docker image is based on the Debian image and I install Apache using RUN apt-get.
When the base image gets updated, I need to remove my container and create a new one. This can be automated, e.g. with Watchtower.
But how can I keep the application inside the container (Apache in my example) up to date? The base image does not change just because a security issue in one package that is not shipped with the base image was fixed. When I create a new container with my Dockerfile, Apache is still not updated thanks to Docker's image cache.
How can I handle application updates as easy as it would be if I would install Apache on the host using the package manager?