[Helm] Add Logstash Output to Elastic Agent Standalone

[btrieger]

What does this PR do?

This PR adds in the Logstash output for elastic agents to the standalone helm chart.

Why is it important?

Without this, standalone agents cannot connect to Logstash clusters. This makes the chart unusable for end users who have logstash in between agent and elasticsearch.

Checklist

• I have read and understood the pull request guidelines of this project.
• 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/fragments using the changelog tool
• I have added an integration test or an E2E test

Disruptive User Impact

This should have no user impact and be backward compatable.

How to test this PR locally

Follow steps in examples/kubernetes-logstash-output

Related issues

• Relates [Helm] Support all options for Elastic Agent Standalone Outputs #10593

[mergify]

This pull request does not have a backport label. Could you fix it @btrieger? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-./d./d is the label that automatically backports to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[pierrehilbert]

Hey @btrieger
Thanks for your contribution.
Could you please add a changelog fragment?

[btrieger]

@pierrehilbert added the changelog fragment

[btrieger]

I added the remaining ssl flags and they should work with any of the outputs. I didn't provide an example of using them as I don't have a functioning logstash cluster that needs them but I did validate that they are being set as expected with a template command. Was thinking maybe I could document all the possible input variables outside the values schema json for every day users. Would it be best to put this in the examples readme for logstash?

On a side note the rest of the outputs should remove the fromYaml and toYaml around the the call to the SSLConfig rendering as it removes the quotes and in the case of ca fingerprints this could prove problematic.

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: dea85f0

History

• 💚 Build #28937 succeeded abbf36b
• 💛 Build #28902 was flaky 469c41f
• 💔 Build #28897 failed 0239e75
• 💔 Build #28891 failed 0577e78

cc @btrieger