Fix certificate reload issue when files are moved

[ramondeklein]

Certificates were not properly reloaded in Kubernetes, because it uses a slightly different method of replacing certificates:

1. Write the new certificate to /tmp/minio/certs/public.crt~.
2. Rename the file /tmp/minio/certs/public.crt~ to /tmp/minio/certs/public.crt.

Since event_linux.go is only watching notify.InCloseWrite it did trigger when public.crt~ is written, but the actual certificate hasn't been updated yet. After adding notify.InMovedTo it also gets triggered after the rename. This caused a race condition between reloading the certificate and the rename operation.

The PR also adds a unit test to check this behavior.

PS: This doesn't seem to be caused by #198. The previous certificate manager also didn't watch the notify.InMovedTo event.

[Copilot]

Pull request overview

This PR fixes certificate reload issues in Kubernetes environments by adding support for file rename operations. Kubernetes updates certificates using a write-then-rename pattern that wasn't being detected by the existing InCloseWrite event watcher on Linux. The fix adds notify.InMovedTo to the watched events and includes comprehensive integration tests to verify the new behavior.

• Adds notify.InMovedTo event to Linux file watcher to detect certificate updates via rename operations
• Introduces integration tests for certificate reload via rename operations
• Increases test timeout to accommodate file system event processing delays

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
certs/event_linux.go	Adds notify.InMovedTo to the list of watched file system events for certificate files on Linux
certs/certificate2_test.go	Adds new test cases and helper function parameter to test certificate reload via rename operations, updates all existing test calls with the new parameter, and increases test timeout for reliability

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

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