feat: add SOCKS proxy support via aiohttp-socks ProxyConnector

[MagicAbdel]

fixes #23797

This PR adds SOCKS proxy support to the asyncio Python client template.
When a kubeconfig cluster entry contains a proxy-url with a SOCKS
scheme (e.g. socks5://localhost:1080), the async client currently
fails with:

aiohttp.client_exceptions.ServerDisconnectedError: Server disconnected

This happens because aiohttp.TCPConnector does not support SOCKS
schemes at the request level — a dedicated ProxyConnector from
aiohttp-socks is required at the session level instead.

Changes

modules/openapi-generator/src/main/resources/python-asyncio/rest.mustache

• Add SUPPORTED_SOCKS_PROXIES frozenset constant for the four SOCKS
  schemes (socks4, socks4a, socks5, socks5h)
• Detect SOCKS scheme via partition("://") — no extra dependencies
• Route SOCKS proxies to aiohttp_socks.ProxyConnector instead of
  aiohttp.TCPConnector
• Lazy import of ProxyConnector so non-SOCKS users are unaffected
• Set self.proxy = None when using SOCKS connector to avoid double
  proxy application per-request

Notes

• HTTP/HTTPS proxy code path completely unchanged
• All four SOCKS schemes supported: socks4, socks4a, socks5, socks5h
• Requires aiohttp>=3.10.0 and aiohttp-socks>=0.9.0
• Complements the urllib3 SOCKS fix for the sync Python client template
• Non-SOCKS users are completely unaffected — aiohttp-socks is never
  imported unless a SOCKS proxy URL is configured
• Users with a SOCKS proxy who don't have aiohttp-socks installed will
  receive a clear ImportError instead of the previous cryptic
  ServerDisconnectedError
• self.proxy is set to None when using ProxyConnector to avoid
  double proxy application — the connector handles routing at the
  connection level, not per-request

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---

Summary by cubic

Add SOCKS proxy support to the asyncio Python client via aiohttp-socks ProxyConnector, fixing failures when proxy-url uses socks* schemes. Fixes #23797.

• New Features

  • Support socks4, socks4a, socks5, socks5h via session-level ProxyConnector.from_url with trust_env=True; HTTP/HTTPS path unchanged; requires aiohttp-socks>=0.9.0.
  • Auto-detect socks* and create the aiohttp ClientSession with ProxyConnector vs TCPConnector; for SOCKS, disable per-request proxy/proxy_headers.

• Refactors

  • Sync template: use partition("://") and a frozenset for SOCKS detection; updated generated samples.
  • Async template: build the session inside the async context and select connector by scheme; removed unnecessary comments.

^{Written for commit 8808735. Summary will update on new commits. Review in cubic}

[cubic-dev-ai]

2 issues found across 7 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="modules/openapi-generator/src/main/resources/python/asyncio/rest.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/python/asyncio/rest.mustache:82">
P2: Configured SOCKS proxy may be conflicted by environment proxy settings because `self.proxy = None` removes the explicit proxy override while `trust_env=True` remains active on the session.</violation>
</file>

<file name="samples/openapi3/client/petstore/python-aiohttp/petstore_api/rest.py">

<violation number="1" location="samples/openapi3/client/petstore/python-aiohttp/petstore_api/rest.py:82">
P1: Connector instantiated in synchronous `__init__` may fail on aiohttp 3.10+ outside a running event loop</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.
Re-trigger cubic}

[cubic-dev-ai]

1 issue found across 2 files (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="modules/openapi-generator/src/main/resources/python/asyncio/rest.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/python/asyncio/rest.mustache:219">
P2: Potential credential disclosure: the ImportError includes the raw proxy URL (`self.proxy`), which may contain embedded credentials (e.g. `socks5://user:pass@host:1080`). This leaks proxy credentials into logs, CI output, or telemetry when aiohttp-socks is missing.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.
Re-trigger cubic}

[MagicAbdel]

@cubic-dev-ai comments addressed