I wrote a comic about overlay filesystems for a potential future container zine this morning, and then I got excited about the topic and wanted to write a blog post with more details. Here’s the comic, to start out: container images are big Container images can be pretty big (though some are really small, like alpine linux is 2.5MB). Ubuntu 16.04 is about 27MB, and the Anaconda Python distribution is 800MB to 1.5GB. Every container you start with an image starts out with the same blank slate,...