I do not have production experience with docker and have several questions regarding a local registry:
dockerfile is the description (=recipe) of how an
image is built(=cooked, e.g.
If the image on my
Docker Host isn't present, it is pulled from a docker registry. As far as I know is Dockerhub regarding the "offical" images of the distributions "safe":
say, I can pull safely the alpine image and indeed get the official image? Or put in another way:
As long, as my images are only based on the "official" images, I do not need a local registry?
What is the advantage of having a (local) registry with ready images in a deployment scenario over building the image on the host off the baseimage (e.g. alpine) and create a new one on the host with few additional git checkouts of code to deploy? or
When does it make sense to pull full images from a (local) registry instead of building on the host? And then: why not using dockerhub private repositories for that?
Is a local registry only a thing of reliability/fallback or is there a gain of "trust" too?
Perhaps a split answer makes sense regarding "small setups" (few images in parallel on a single host, "releases" once a week) vs "cloud scale" ( many images in parallel, many hosts, several releases a day) where the reasons are more obvious.