It doesn't have anything to do with a commit breaking anything. It has to do with reproducability. As others have mentioned, a Dockerfile isn't perfect (I'd arg

It doesn't have anything to do with a commit breaking anything. It has to do with reproducability. As others have mentioned, a Dockerfile isn't perfect (I'd argue Dockerfile+Nix is pretty close) but at least you don't have to ask "Oh god, what did OJ Ford run manually before commiting the image we use in Prod." That's truly horrific and simply isn't a problem if you use a Dockerfile. >Not everything's open source. I don't know what that means. Whether the source is closed or not has zero impact on the use-cases I'm discussing for Docker. Even if the source of the base layer isn't available, it doesn't stop you from using that base layer in a new Dockerfile, at all.