In this chapter, we have looked at being able to sign your images using the components of Docker Content Trust as well as hardware signing using Docker Content Trust along with the third party utilities in the form of YubiKeys. We also took a look at Docker Subscription that you can utilize to your advantage to help set up not only secure Docker environments but also ones that are supported by those at Docker itself. We then looked at DTR as a solution that you can use to store your Docker images. Lastly, we looked at the Docker Registry, which is a self hosted registry that you can use to store and manage your images. This chapter should help give you enough configuration items to chew on to help you make the right decision as to where to store your images.

In the next chapter we will be looking at securing/hardening Linux kernels. As the kernel is what is used to run all your containers, it is important that it is secured in the proper way to help alleviate any security related issues. We will be covering some hardening guides that you can use to accomplish this goal.