[8.x](backport #41477) [AWS] [EC2] enrich events with EC2 tags with add_cloud_metadata processor

[mergify]

Proposed commit message

This PR adds support to enrich events with EC2 tags iff,

• IMDS endpoint is enabled ¹
• Tag access is enabled through IMDS endpoint. ²

Tags are added to event payload with key aws.tags.<KEY>,

{
  "aws" : {
   "tags" : {
      "org" : "acme",
      "owner" : "userA"
    }
   }
}

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.

How to test this PR locally

The best way to validate this is through a beats deployment (ex:- metricbeat) in an EC2 instance.

• Create an EC2 instance
  • Enable IMDS endpoint
  • Enable tags access through IMDS endpoint
  • Assign instance with a role with adequate permissions
  • Add few tags to the instance
• Build metricbeat from this branch
• Deploy custom build into EC2
• Enable add_cloud_metadata processor
• Run and observe metrics containing tags

Related issues

Closes #31899

Screenshots

Footnotes

1. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-options.html ↩

2. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/work-with-tags-in-IMDS.html#allow-access-to-tags-in-IMDS

   ---

   This is an automatic backport of pull request [AWS] [EC2] enrich events with EC2 tags with add_cloud_metadata processor #41477 done by Mergify. ↩

[elasticmachine]

Pinging @elastic/obs-ds-hosted-services (Team:obs-ds-hosted-services)