x-pack/filebeat/input/cel: add support for partial evaluation debug logging

[efd6]

Proposed commit message

See title.

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.

Author's Checklist

• [ ]

How to test this PR locally

Run go test -v -run TestInput/debug in the cel package. You should see the logs for the test, including a line like so

{"log.level":"debug", ... ,"log.logger":"cel_test.cel_debug"," ... ,"message":"DEBUG", ... ,"tag":"partial sum","value":5, ...}

for the happy path test and like so

{"log.level":"debug", ... ,"log.logger":"cel_test.cel_debug", ... ,"message":"ERROR", ... ,"tag":"divide by zero","error":{"message":"division by zero"}, ...}

for the error path test.

The surprising field rename from "value" to "error" that is not explainable from the code in this change is undocumented pixie dust from zap. I guess it's OK.

Related issues

• Depends x-pack/filebeat/input/cel: update mito version to v1.6.0 #36651

Use cases

Screenshots

Logs

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2023-09-28T22:10:02.296+0000

• Duration: 25 min 5 sec

❕ Flaky test report

No test was executed to be analysed.

🤖 GitHub comments

Expand to view the GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

• /package : Generate the packages and run the E2E tests.

• /beats-tester : Run the installation tests with beats-tester.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b cel_debug upstream/cel_debug
git merge upstream/main
git push upstream cel_debug

[kcreddy]

LGTM 👍🏼
I guess there is no easy way to create unit test if log is being produced with the specified tag ?

[efd6]

The logging behaviour is hard to test here, but is tested in the library. elastic/mito#40 (testdata/debug.txt)

[efd6]

/test

[efd6]

/test