feat(elasticsearch sink): Support Amazon OpenSearch Serverless

[handlerbot]

Summary

The elasticsearch sink can now write to Amazon OpenSearch Serverless collections by signing requests with AWS Signature V4 algorithm, specifying the aoss service.

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

Stood up an Amazon OpenSearch Serverless collection, configured vector to send any files in a test directory to an index in that collection, verified they were written successfully by querying the index stats and the index itself.

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

• Please read our Vector contributor resources.

References

• Closes: Support AWS OpenSearch Serverless for elasticsearch sink #16252

[handlerbot]

• This work builds upon @AvihaiSam's work in https://github.com/AvihaiSam/vector/tree/feature/opensearch-serverless; they granted me permission to build upon it in here: Support AWS OpenSearch Serverless for elasticsearch sink #16252 (comment)
• This is my first contribution to Vector, and also my first modification of anything written in Rust, so it's entirely possible I have submitted something that is not idiomatic Rust, or could be more optimal. Apologies && newbie feedback welcomed. 🙇🏻
• (I am particularly uncertain about the correctness of the Serde comments, and how they influence the documentation. I expect I may not have gotten that exactly right, and some tweaks may be needed...)

[AvihaiSam]

• This work builds upon @AvihaiSam's work in https://github.com/AvihaiSam/vector/tree/feature/opensearch-serverless; they granted me permission to build upon it in here: Support AWS OpenSearch Serverless for elasticsearch sink #16252 (comment)

Thanks for the credit! Great work!

[handlerbot]

Docs are in; I think this one is completely ready for review! 🙇🏻

[pront]

Hi @handlerbot, thank you and I will take a look shortly.

[handlerbot]

@rtrieu Sent it over to you for docs re-review. The Check Spelling test is failing because today after a check-spelling upgrade on the GitHub Actions side, Non-existent discovered in website/cue/reference/remap/expressions/path.cue is considered a no-no. This isn't a file I have touched in my work in this PR, and while I'm glad to run the auto-updater for .github/actions/spelling/expect.txt when prompted, I am not sure what to do re: path.cue, and I think that should be fixed in a separate PR? 🙇🏻

UPDATE[0]: I decided to just replace non-existent with nonexistent in path.cue, and now nothing shows up as a clear error in the log, but the test is still failing? ¯_(ツ)_/¯

UPDATE[1]: I guess it's these, which are all about extra dictionaries that can't be downloaded, or non-alpha entries in the dictionary? Those are definitely not from anything I did in this! 😹

[:x: extra-dictionary-not-found](https://docs.check-spelling.dev/Event-descriptions#extra-dictionary-not-found) | 11
[:warning: non-alpha-in-dictionary](https://docs.check-spelling.dev/Event-descriptions#non-alpha-in-dictionary) | 2

[pront]

Thank you @handlerbot!

[handlerbot]

@pront Pushed a commit from cargo fmt, please reapprove code and workflows? 🙇🏻

[pront]

Apologies, the spell checker was broken. Please undo the spell checker related changes, rebase on latest master and push again to get a fresh report.

[handlerbot]

@pront Ready!

[handlerbot]

@pront If you're working today, could I get a quick re-approve on this? It would be awesome for our internal velocity if I could get this into the next vector release, and it feels like that might be sooner rather than later. 🤞🏻🙇🏻 🚀

[pront]

@pront If you're working today, could I get a quick re-approve on this? It would be awesome for our internal velocity if I could get this into the next vector release, and it feels like that might be sooner rather than later. 🤞🏻🙇🏻 🚀

Hi @handlerbot, I am doing a final pass now. We have plenty of time till the next Vector release ;)

[pront]

Thank you! I appreciate the good documentation in this PR.

[handlerbot]

@pront TYVM for the compliment, and thank you for the thorough and prompt review! 🙇🏻

Do we need any additional approvals re: documentation or other, or is this ready to be merged at next working time?

[pront]

@pront TYVM for the compliment, and thank you for the thorough and prompt review! 🙇🏻

Do we need any additional approvals re: documentation or other, or is this ready to be merged at next working time?

All good, now merged.

[handlerbot]

Thank you @pront and @rtrieu for the reviews, and @AvihaiSam for starting this out! 🌟