authentication - How to authenticate docker hub api request? -

i have been trying past several hours make authenticated request docker hub api. first of all, let me documentation unclear. there several different subdomains have cycle through. ones have seen index.dockerhub.io, registry-1.docker.io/v1/ auth.docker.com/token. there others. point. api managed 30 different people or , forgot have meeting how unify api. feels have read find on internet how trying do, , still unclear me supposed do.

their documentation states supposed auth token before making request. ok. fine. how do that? got lucky , stumbled across endpoint, https://auth.docker.io/v2/token/ no api. found guessing. don't know version 2 capable of doing trying do.

what steps need take make authenticated request dockerhub api. trying more specifically, trying query information given images on hub, size of images, , basic port information available. know possible, because have used services it. so, how authenticate request information?

so after few more hours of working on problem, came across had similar issues , wrote blog post how solve it. short answer endpoint missing docker api documentation https://cdn-registry-1.docker.io/v1/. why didn't document api better? don't know. if wants read full article how done, can find @ http://www.appcontainers.com/requesting-image-information-using-the-public-docker-api/

this helpful article have found on subject. other poor soul trapped in confusion known docker api.