Python Remote URL construction incorrectly appends `/simple/`, breaking Gitea PyPI integration

[oguzhanmeteozturk]

Version

• Pulp Operator: v1.0.0

Describe the bug

The pulp-python plugin unconditionally appends the /simple/ suffix to the url provided for a Python remote. This behavior is hardcoded and assumes the remote URL points to a repository root that needs /simple/ added to reach the PEP 503 index.

This assumption breaks compatibility with PyPI-compatible registries like Gitea, where the complete, non-modifiable simple index URL is already provided. The forced suffix leads to incorrect URL generation.

To Reproduce
* Gitea Instance with a PyPI Registry: e.g., https://gitea.example.xyz
* Target Gitea PyPI URL: https://gitea.example.xyz/api/packages/example/pypi/simple/

• Attempt 1: Provide the full, correct URL ending in /simple/

    pulp python remote create \
        --name gitea-remote-full \
        --url https://gitea.example.xyz/api/packages/example/pypi/simple/ \
        --username <user> \
        --password <pass>
    
    pulp python repository create --name test-repo-1
    pulp python repository sync --name test-repo-1 --remote gitea-remote-full

• Attempt 2: Provide the URL without the /simple/ suffix

    pulp python remote create \
        --name gitea-remote-base \
        --url https://gitea.example.xyz/api/packages/example/pypi \
        --username <user> \
        --password <pass>
  
    pulp python repository create --name test-repo-2
    pulp python repository sync --name test-repo-2 --remote gitea-remote-base

Pulp's automatic suffixing logic causes 404 errors in both scenarios.

1. In Attempt 1, Pulp appends an extra /simple/, resulting in a "double suffix":

   • URL requested: https://gitea.example.xyz/api/packages/example/pypi/simple/simple/
   • Result: 404 Not Found.

2. In Attempt 2, Pulp strips the last path segment (/pypi) and appends /simple/, also forming an incorrect URL:

   • URL requested: https://gitea.example.xyz/api/packages/example/simple/
   • Result: 404 Not Found.

Expected behavior
Pulp should respect the provided url for a Python remote. When a URL is provided, Pulp should either:
a. Use the URL as-is, without modification.
b. Check if the URL already ends with /simple/ and, if so, refrain from appending it again.

For the configuration in Attempt 1, Pulp should make requests directly to https://gitea.example.xyz/api/packages/example/pypi/simple/.

Additional context
This behavior makes it impossible to use Gitea as a PyPI remote source for Pulp. More broadly, it limits Pulp's compatibility with any PyPI-compliant repository that provides a full, unchangeable URL to its simple index and does not conform to the exact .../ -> .../simple/ transformation that Pulp enforces.

A fix should be relatively easy: Modify the URL construction logic to first check if url.endswith('/simple/'). If true, use the URL as-is

This would provide the necessary flexibility to integrate with a wider range of non-standard but popular PyPI-compatible endpoints like Gitea.

[gerrod3]

Have you tried syncing with the remote url including the trailing slash without '/simple/? i.e
--url https://gitea.example.xyz/api/packages/example/pypi/

I tested on our fixtures at https://fixtures.pulpproject.org/python-pypi/ and notice the sync would fail if I didn't include the trailing slash.

Second question, does Gitea support the PyPI json api? https://docs.pypi.org/api/json/ This is what Pulp (bandersnatch) uses to fetch the package metadata for syncing. The sync will fail if this api is not available. However, you can still use the index for pull-through caching if it is PEP-503 compliant.