ipv6 issues

[peter-facko]

Hello @AllexVeldman,

I tried using this project again and I tried publishing a package as

uv publish package-0.1.0.tar.gz --publish-url "https://pyoci.com/example.com/path/"

I used docker.io and my own https://github.com/project-zot/zot instance. Both give me

error: Failed to publish `package-0.1.0.tar.gz` to https://pyoci.com/example.com/path/
  Caused by: POST requests are not supported by the endpoint, are you using the simple index URL instead of the upload URL? Server says:

How do I debug this?

[AllexVeldman]

Hi @peter-facko,
From what I can see in the logs of pyoci.com you might be missing a trailing / in the urls you used.

uv is included in the examples (https://github.com/AllexVeldman/pyoci/blob/main/docs/examples/uv/publish/pyproject.toml,

pyoci/docs/examples/justfile

Line 40 in 8429f59

uv-publish version username token repository="http://localhost:8080/ghcr.io/allexveldman/": (_group "uv-publish") && _endgroup

)
which ran successfully on the current release: https://github.com/AllexVeldman/pyoci/actions/runs/19062601101/job/54445912720

So I expect it to work.

To debug you could run pyoci locally docker run --rm -p8080:8080 ghcr.io/allexveldman/pyoci:0.1.32 and using http://127.0.0.1:8080/<registry>/<namespace>/ as the index url.

To get more logs, add -e RUST_LOG=debug to the docker run

[AllexVeldman]

I could reproduce the error you mention locally by not setting the trailing / in the index-url:

+ uv publish --publish-url http://localhost:8080/http%3A%2F%2Fregistry%3A5000/pyoci/python --username foo --password bar
Publishing 2 files http://localhost:8080/http%3A%2F%2Fregistry%3A5000/pyoci/python
Uploading hello_world-0.1.0+1234.uv-py3-none-any.whl (1.5KiB)
error: Failed to publish `dist/hello_world-0.1.0+1234.uv-py3-none-any.whl` to http://localhost:8080/http%3A%2F%2Fregistry%3A5000/pyoci/python
  Caused by: POST requests are not supported by the endpoint, are you using the simple index URL instead of the upload URL? Server says:

successfull upload:

+ uv publish --publish-url http://localhost:8080/http%3A%2F%2Fregistry%3A5000/pyoci/python/ --username foo --password bar
Publishing 2 files http://localhost:8080/http%3A%2F%2Fregistry%3A5000/pyoci/python/
Uploading hello_world-0.1.0+1234.uv-py3-none-any.whl (1.5KiB)
Uploading hello_world-0.1.0+1234.uv.tar.gz (1.2KiB)

[peter-facko]

@AllexVeldman, thank you, that was the problem! Maybe an error message or supporting paths without a trailing slash would be good.

However, I tried both registries with the trailish slash and I get two different errors. The personal OCI registry is IPv6 only (so no A record in DNS, just AAAA) and gives me this:

Caused by: Upload failed with status code 500 Internal Server Error. Server says: error sending request for url (https://example.com/v2/x/package/manifests/0.1.0): client error (Connect): dns error: failed to lookup address information: Try again

docker.io on the other hand gives me:

Caused by: Upload failed with status code 500 Internal Server Error. Server says: Unknown Content-Type: text/html; charset=UTF-8

[AllexVeldman]

The personal OCI registry is IPv6 only (so no A record in DNS, just AAAA)

I tried looking up the host you are using and I'm not getting any IPs, v4 or v6.
Can you check the output of dig AAAA <domain>?

[AllexVeldman]

docker.io on the other hand gives me:

Caused by: Upload failed with status code 500 Internal Server Error. Server says: Unknown Content-Type: text/html; charset=UTF-8

I never tested docker.io, from what I can see https://docker.io/v2/<namespace>/<image>/manifests/0.1.0 redirects to https://www.docker.com/v2/<namespace>/<image>/manifests/0.1.0 which redirects to https://www.docker.com/, so the error you see is correct, docker.io results in the docker home page which is not the registry.

From what I can find you need registry-1.docker.io (https://docs.docker.com/reference/api/registry/latest/#tag/pull)

[AllexVeldman]

The personal OCI registry is IPv6 only (so no A record in DNS, just AAAA)

I tried looking up the host you are using and I'm not getting any IPs, v4 or v6. Can you check the output of dig AAAA <domain>?

@peter-facko After a bit of digging (pun intended) I think the issue is that you are missing a DNS record for your sub-domain.

[peter-facko]

@AllexVeldman, thank you, if the DNS doesn't work, I can solve it with running a local PyOCI instance, so that's not the problem.

I tried registry-1.docker.io and I guess I got a bit further because now I get a whole HTML page, which basically says "502 Bad Gateway".

Also, docker.io not working is weird because that's what everyone is using when accessing Docker Hub. In podman, the default behavior is that when you don't specify the registry, docker.io gets prepended.

[AllexVeldman]

Also, docker.io not working is weird because that's what everyone is using when accessing Docker Hub. In podman, the default behavior is that when you don't specify the registry, docker.io gets prepended.

Not providing a registry is a shortcut to pull from dockerhub that seems to be widely adopted.
From what I can find most tools that interact with docker hub have hardcoded substitutions from docker.io to registry-1.docker.io (docker/cli#3793 (comment)).

As for the 502, I can see the authentication was successful but no subsequent request happens, which is weird, can you provide the log when running pyoci locally with RUST_LOG=debug? Never mind, found the log I'm looking for.

[AllexVeldman]

Full error message:

Upload failed with status code 502 Bad Gateway. Server says: Failed to parse authentication response: duplicate field `token` at line 1 column 2999

[AllexVeldman]

fix for registry-1.docker.io: #321

[AllexVeldman]

Released in https://github.com/AllexVeldman/pyoci/releases/tag/v0.1.33

@peter-facko is the DNS issue you saw also cleared up or is there still an issue there?

[peter-facko]

Thank you, Docker Hub works for me now!

I still get 502 for bad credentials, but that's usable.

I am still debugging my private registry, will report.

I think I won't be able to solve the globally resolvable DNS issue, because I think the problem is that my private DNS server for the subdomain is IPv6-only as well.

[peter-facko]

@AllexVeldman, I am trying to get a local instance to work, but I am getting

Caused by: Failed to send POST request
Caused by: error sending request for url (http://localhost:8080/<host>/<path>/)
Caused by: client error (SendRequest)
Caused by: error writing a body to connection
Caused by: Connection reset by peer (os error 104)

I get this with 0.1.32 and 0.1.33, with both the uv example and manual uv publish of my package.

[peter-facko]

I forgot to add that PyOCI logs show nothing, just

2025-11-25T16:13:39.139838Z  INFO Tracing initialized
2025-11-25T16:13:39.139854Z  INFO Listening on 0.0.0.0:8080

[AllexVeldman]

@peter-facko I ran into the same before with podman, try 127.0.0.1 instead of localhost.

For some reason the compose file I use for development does not have this issue, did not dig deeper yet though.