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 using aiohttp-socks ProxyConnector, fixing failures when proxy-url uses socks* schemes. Fixes #23797.

• New Features

  • Support socks4, socks4a, socks5, socks5h via session-level ProxyConnector.
  • Auto-detect proxy scheme; aiohttp HTTP/HTTPS behavior unchanged.
  • Lazy import; avoids double proxy by clearing per-request proxy/header fields.
  • Requires aiohttp>=3.10.0 and aiohttp-socks>=0.9.0 (install when using SOCKS).

• Refactors

  • Simplified SOCKS detection in the sync template: use partition("://") and a frozenset of schemes (no helper function).

^{Written for commit c0cd45c. 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]

P1: Connector instantiated in synchronous __init__ may fail on aiohttp 3.10+ outside a running event loop

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At samples/openapi3/client/petstore/python-aiohttp/petstore_api/rest.py, line 82:

<comment>Connector instantiated in synchronous `__init__` may fail on aiohttp 3.10+ outside a running event loop</comment>

<file context>
@@ -74,8 +76,27 @@ def __init__(self, configuration) -> None:
+        proxy = configuration.proxy
+        proxy_scheme = (proxy or "").partition("://")[0].lower()
+
+        if proxy_scheme in SUPPORTED_SOCKS_PROXIES:
+            # SOCKS proxies require ProxyConnector - aiohttp TCPConnector
+            # does not support SOCKS schemes
</file context>

[cubic-dev-ai]

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.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At modules/openapi-generator/src/main/resources/python/asyncio/rest.mustache, line 82:

<comment>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.</comment>

<file context>
@@ -65,8 +67,27 @@ class RESTClientObject:
+                limit=self.maxsize,
+                ssl=self.ssl_context,
+            )
+            self.proxy = None          # connector handles proxy
+            self.proxy_headers = None  # not applicable for SOCKS
+        else:
</file context>