Request for official Hub repository using v2 API

[CermakM]

Hello, I am trying to query tags from official Docker Hub repository.
What I am doing is getting response to 'GET' request on:

https://hub.docker.com/v2/repositories/<namespace>/<repo>/tags/

Which works just fine for public user repos like fedora/apache.
My question is how to query official repo, ie. fedora

I tried
https://hub.docker.com/v2/repositories/fedora/tags/

or using _ and official as <namespace>

None of it works. I'd really appreciate your help.

Thank you,
Marek.

[thaJeztah]

Docker Hub (hub.docker.com) is not the registry you're pulling from; Docker Hub is a web interface that allows you to browse the repositories/images that are available to pull from the Docker Registry

The registry itself is at https://registry-1.docker.io

Also see https://github.com/moby/moby/blob/master/contrib/download-frozen-image-v2.sh which is a shell script to download images without using docker, and may provide some insight as to what docker does when pulling an image

[CermakM]

Hi, thank you for the answer. The link is useful, I'll check it out.
However, what I was doing up until now was just searching through the repositories and tags, so I basicly didn't need the registry itself, since I did not need to push/pull - that way I avoided the authentication. Querying the hub.docker.com/v2 was sufficient.
Are you telling me that* a)* this is not the right way to do it and b) there is no way to query an official repo like that? It works very well for the namespace/repository repos, tho.

[CermakM]

By the way, using the registry... could you help me out with authentication to the registry? I kinda tried to follow the Docker guide I am still getting error: invalid token and message: "authentication required" ..
the ways I tried to query token:
https://auth.docker.io/token?serivce=registry.docker.io&scope=repository:fedora:pull for fedora repo
https://auth.docker.io/token?serivce=registry.docker.io&scope=registry:catalog:* and without :* at the end for registry catalog

I recieved the token in all cases, then I used it in the authorization header as Authorization: Bearer <token> for f.e https://registry-1.docker.io/v2/fedora/tags/list and https://registry-1.docker.io/v2/_catalog .. then I keep getting the error mentioned.
I appologize if this is kind of a stupid question, I am not very well-read in the topic of http requests etc. and I really appreciate your help.

[thaJeztah]

I think there's two tokens in use; a short-lived token for pulling each image, and an authorisation header if to access private repositories. What exactly are you trying to do? I this to get a list of tags for a repository?

[CermakM]

Yes, I know. At the moment I want to list tags and description of an official repository. It works for public repositories like fedora/apache, but not for the official ones, like fedora.

[thaJeztah]

Does it work if you use library/fedora instead of just fedora? Even though official images show up as <somename>, the actual images are located in library/<somename>

[CermakM]

Aaah there we go... Finally it works. If it is in docs and I missed it then well.. serves me right.. Otherwise this should really be stated somewhere.

Thank you very much.

[tmc9031]

@CermakM how to get registry image tag, i also try "curl https://registry-1.docker.io/v2/_catalog"
but not work

[CermakM]

@tmc9031 you need to provide authorization token to the curl as well, see the example from this conversation, official documentation or place a question on https://stackoverflow.com/. If you think there is an issue or bug in the implementation, open another issue ;).

[mlandisbqs]

I couldn't make this work and did not want to create an api token to query public information on available tags. I found this api URL works for GET or HEAD:

  // omit the tag if you want a list...
  await axios.head(`https://hub.docker.com/v2/repositories/library/node/tags/${nodeLtsVersion}`);

YMMV

[thaJeztah]

@mlandisbqs that's the Docker Hub API (so specific to Docker Hub, not the registry); it's documented in the "reference" section of the documentation; https://docs.docker.com/reference/;

That endpoint is documented here;

https://docs.docker.com/docker-hub/api/latest/#tag/repositories/paths/~1v2~1namespaces~1%7Bnamespace%7D~1repositories~1%7Brepository%7D~1tags/get

[mlandisbqs]

@thaJeztah -- this was my experience based on that doco...

not sure what the special sauce is to make that work

[thaJeztah]

library is the namespace for the official images; the _ is something the router uses for the GUI (honestly, don't know where that came from, but it was introduced a long time ago)