.../input/entityanalytics/provider/okta: Handle 429s, concurrent limits

[chrisberkhout]

Proposed commit message

.../input/entityanalytics/provider/okta: Handle 429s, concurrent limits

- Retry requests that get a 429 response, up to a maximum number of
  retries.
- If the concurrent rate limit[1] is exceeded, reset to the default
  initial rate, rather than to zero.

[1] https://developer.okta.com/docs/reference/rl-best-practices/#example-rate-limit-header-with-concurrent-rate-limit

Discussion

Hiding whitespace changes will greatly improve the readability of the diff for x-pack/filebeat/input/entityanalytics/provider/okta/internal/okta/okta.go. It's mostly indentation changes.

For the concurrent rate limit, the previous behavior was to reset to a rate of zero, which would cause an error because the next wait would exceed the maximum wait time.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Related issues

• Relates x-pack/filebeat/input/entityanalytics/provider/okta: Rate limiting hangs #40106

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @chrisberkhout? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit

[mergify]

backport-8.x has been added to help with the transition to the new branch 8.x.
If you don't need it please use backport-skip label and remove the backport-8.x label.

[efd6]

nits only

[efd6]

Prefer log._w over log._f.

[chrisberkhout]

Done

[efd6]

Linter is correct here, this is an ineffassign.

[chrisberkhout]

The line is actually unnecessary. Removed.

[efd6]

Needs goimports or manual separation.

[chrisberkhout]

This was less automatic than I expected. Fixed.