fix: Remove KeepAlive socket option

[Angelinsky7]

What does this PR do?

On some platform the TCPClient fail to connect because of KeepAlive settings.

Why is it important?

If the client fail to connect, TestContainer does not work at all.

Related issues

Relates dotnet/runtime#24917
Closes #1670

Summary by CodeRabbit

• Bug Fixes
  • Improved handling of resource connection stability on certain platforms.

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[coderabbitai]

Walkthrough

Removes the TCP keep-alive socket option assignment from ResourceReaper.MaintainRyukConnection and replaces it with commented-out code and a note referencing a PlatformNotSupportedException scenario. This reverts a change that caused Ryuk connection failures in certain environments following the 4.11.0 upgrade.

Changes

Cohort / File(s)	Summary
Ryuk Keep-Alive Socket Configuration src/Testcontainers/Containers/ResourceReaper.cs	Removed tcpClient.Client.SetSocketOption() call for TCP keep-alive; replaced with commented-out code and explanatory note referencing platform exception handling.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related PRs

• fix(ResourceReaper): Set wait strategy #1634: Modifies TCP keep-alive handling in the same ResourceReaper.MaintainRyukConnection method, with opposing intent (adds vs. removes keep-alive socket option).

Suggested labels

bug

Poem

🐰 A socket once kept so alive,
Caused Ryuk's connection to dive,
We've commented it out,
No more connection drought,
Now the reaper and client both thrive! 🔌✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description check	✅ Passed	The description includes what the PR does and why it's important, but lacks recommended 'How to test' section and doesn't provide explicit step-by-step testing guidance.
Linked Issues check	✅ Passed	The PR directly addresses issue #1670 by removing the KeepAlive socket option that was causing client connection failures on some platforms, meeting the core requirement.
Out of Scope Changes check	✅ Passed	All changes are scoped to the ResourceReaper.cs file and directly address the KeepAlive socket issue causing the connection regression; no out-of-scope modifications detected.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Title check	✅ Passed	The title accurately summarizes the main change: removing the KeepAlive socket option from the TCP client connection to fix a platform-specific connection failure issue.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

🧹 Nitpick comments (1)

src/Testcontainers/Containers/ResourceReaper.cs (1)

307-308: Clean up the KeepAlive note (typo + commented-out code).

Line 307 has a typo (“plateform”), and Line 308 leaves disabled code in place. Prefer a plain rationale comment (with issue reference) instead of commented-out executable code.

Suggested cleanup

-          // On some plateform the connection fail with PlatformNotSupportedException: Sockets on this platform are invalid for use after a failed connection attempt.
-          // tcpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);
+          // KeepAlive is intentionally not set due to platform-specific failures after failed connect attempts.
+          // See: https://github.com/dotnet/runtime/issues/24917.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/Testcontainers/Containers/ResourceReaper.cs` around lines 307 - 308, In
ResourceReaper where the KeepAlive note appears, replace the typo-filled comment
and the commented-out tcpClient.Client.SetSocketOption(...) line with a concise
rationale: correct "plateform" to "platform", remove the disabled code, and add
a short comment stating that KeepAlive calls were intentionally omitted because
they can throw PlatformNotSupportedException on some platforms (include an
internal issue/PR reference if needed); locate the comment near the TcpClient
usage (the code that previously referenced tcpClient.Client.SetSocketOption) and
update it accordingly.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@src/Testcontainers/Containers/ResourceReaper.cs`:
- Around line 307-308: In ResourceReaper where the KeepAlive note appears,
replace the typo-filled comment and the commented-out
tcpClient.Client.SetSocketOption(...) line with a concise rationale: correct
"plateform" to "platform", remove the disabled code, and add a short comment
stating that KeepAlive calls were intentionally omitted because they can throw
PlatformNotSupportedException on some platforms (include an internal issue/PR
reference if needed); locate the comment near the TcpClient usage (the code that
previously referenced tcpClient.Client.SetSocketOption) and update it
accordingly.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 71183c3f-273c-496a-a53c-63debf4fade4

📥 Commits

Reviewing files that changed from the base of the PR and between 598f961 and 77128ad.

📒 Files selected for processing (1)

• src/Testcontainers/Containers/ResourceReaper.cs

[HofmeisterAn]

Thanks