Fixes 404 error when authenticating with v2 reg

[dylanrhysscott]

After applying this fix I can successfully authenticate with github registry

[vagrant@localhost nerdctl]$ nerdctl login -u <USERNAME> ghcr.io
Enter Password:
Login Succeeded
[vagrant@localhost nerdctl]$

[vagrant@localhost ~]$ nerdctl pull ghcr.io/<IMAGE>
ghcr.io/<IMAGE>:                            resolved       |++++++++++++++++++++++++++++++++++++++|
manifest-sha256:9d7715dd1e7a20a03c1fda6b625ab73aa8e1a9cacddad885b79876bd2a8ebce8: done           |++++++++++++++++++++++++++++++++++++++|
config-sha256:6f7f6bfd79125762caacefdb0e83ece7e101c85279d31fbc36f61d643f878a42:   done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:abd092694f3b3635a1642c6fed15a81f02bbcd44045fc5dfb138eda3531899bf:    done           |++++++++++++++++++++++++++++++++++++++|
layer-sha256:b53a42fddd847a0d1d550565601c9299fecae84e94ffcb8c9a9e5e98231e0ee0:    done           |++++++++++++++++++++++++++++++++++++++|
elapsed: 3.8 s                                                                    total:  7.8 Mi (2.1 MiB/s)
[vagrant@localhost ~]$

This maybe a slightly naive approach so welcome feedback on a better place for this - Not sure who to ping from containerd

Closes #715

[alisson276]

if !strings.HasSuffix(rh.Path, "/") {
  rh.Path += "/"

This way you avoid hard-coded v2 in the code. Don't you think?

[dylanrhysscott]

Thanks I'd forgotten about HasSuffix from that package - looks like this PR will be closed off and merged elsewhere but that would be a better approach

[dylanrhysscott]

@AkihiroSuda @alisson276 I'm looking at this suggestion and I'm not sure to implement seems a good change but as far as I can tell the login issues are only affecting v2 and adding this applies it to every version of registry - Would it be best to just apply the leading slash to /v2 only or globally?

[AkihiroSuda]

I think just checking if rh.Path == "/v2" is fine.

[alisson276]

I just think that keep in sync with the containerd library is not a good idea. If, for any reason, they change that path, it must be synced here. If you are worried about always adding a slash, the safest approach is to try twice: first using the rh.Path (no matter what it is, if v2, v3, whatever) and if fails, do a second try appending the slash at the end (IMO).

[alisson276]

If I correctly understood, in the PR they are asking to add this explicit in the GET call... in other words, do a:

req, err := http.NewRequest(http.MethodGet, u.String() + "/", nil)

So, this if is ok, I just don't know if fixing the v2 is a good idea, but this is just my opinion. I'm just trying to contribute because this problem afftects my environment too.

In docker CLI it doesn't happen. do you know how this is handled there?

[dylanrhysscott]

@alisson276 v2 is part of the docker registry specification which I think is pretty static and as far as I know unlikely to change but it maybe a valid concern in future - with regards to doesn't happen with Docker question docker uses the dockerd daemon and not containerd directly as well as using /v1 and not /v2. This might explain the difference

[AkihiroSuda]

Thanks, I'm closing this, as we now have containerd/containerd#6470

#724 (comment)

[AkihiroSuda]

Reopened per discussion in containerd/containerd#6470 .
Sorry for going back and force.

[AkihiroSuda]

Thanks