Fix duplicate location in NGINX config (#10090)

[ailurarctos]

When creating ingresses that use the same path with a mix of Exact and Prefix path types nginx-ingress-controller can generate an NGINX config with a duplicate location:

nginx: [emerg] duplicate location "/a/" in /tmp/nginx/nginx-cfg2287376726:693
nginx: configuration file /tmp/nginx/nginx-cfg2287376726 test failed

The issue is that nginx-ingress-controller stops looking for duplicates once it sees the same path with a different path type.

What this PR does / why we need it:

This is a PR to fix https://github.com/kubernetes/ingress-nginx/issues/10090.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] CVE Report (Scanner found CVE and adding report)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation only

Which issue/s this PR fixes

fixes #10090

How Has This Been Tested?

I added a test for the change. I also ran all tests in https://github.com/kubernetes/ingress-nginx/blob/main/docs/developer-guide/getting-started.md#testing.

Checklist:

• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I've read the CONTRIBUTION guide
• [x] I have added unit and/or e2e tests to cover my changes.
• [x] All new and existing tests passed.

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: ailurarctos / name: Gordon Honda (4f2950febb8ec7f3ce7dd8880954858ff25fe8d0)

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[longwuyuan]

@ailurarctos thanks for the contribution.

I see this in the related issue

Note that the admission webhook is disabled as it does not allow for identical paths. Identical paths can be useful when doing a migration from one ingress to another.

Can you clarify ,if this protection from duplication PR, is assuming that the admission webhook is deleted.

[ailurarctos]

Can you clarify ,if this protection from duplication PR, is assuming that the admission webhook is deleted.

Yes. I put more details in https://github.com/kubernetes/ingress-nginx/issues/10090#issuecomment-1595684997.

[strongjz]

/ok-to-test

[tao12345666333]

/assign

[tao12345666333]

Sorry for the delay. I will add this to my list, and finish the review on Friday. Thanks

[DemIG]

@tao12345666333 sorry, did you have a chance to review this pr?

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