transferring from issue-573078166:

It would be great to expand the guidance in AIP-163 on how to handle standard methods and general resource lifecycle.

For example, what is the expected behavior of a Create or Delete with validation_only flag set?

• Should Create return 200 OK on dryrun success?
• Is it OK for a subsequent GET to return 404 if Create returned 200?
• Would it be advised (or OK) for Create to return 412 PRECONDITION FAILED or similar instead?

A couple places where an amendment for dry run could help:

https://aip.dev/151:

When creating or deleting a resource with a long-running operation, the resource should be included in List and Get calls; however, the resource should indicate that it is not usable, generally with a state enum.

https://aip.dev/135:

The Delete method should succeed if and only if a resource was present and was successfully deleted.

Happy to add something for this. Incidentally. the answers to these questions are:

Should Create return 200 OK on dryrun success?

Yes.

Is it OK for a subsequent GET to return 404 if Create returned 200?

Yes (and anything else would not make sense).

Would it be advised (or OK) for Create to return 412 PRECONDITION FAILED or similar instead?

No. The dry run succeeded.

a request using validate_only must fail if the actual request would fail for any reason.

This seems overly strong: a validate_only call typically would not create state in a database, but certain classes of errors can only happen when a call to commit a transaction is actually made.

This seems overly strong: a validate_only call typically would not create state in a database, but certain classes of errors can only happen when a call to commit a transaction is actually made.

This is a great point, thanks @jasonmc. I have amended the language to: "a request using validate_only must fail if it determines that the actual request would fail."

It would be great to expand the guidance in AIP-163 on how to handle standard methods and general resource lifecycle.

I did a minor re-word to try and be more clear about this; let me know if you think it is clear enough.