Improve Health Status of security-auditlog Index in Single Node Clusters

[Ganesh-RB]

Description

Bug Fix: Improve Health Status of security-auditlog Index in Single Node Clusters

This pull request addresses an issue where the security-auditlog index was showing a yellow health status in single node clusters. The problem was caused by the use of indexrequest default settings, which were not optimal for single node environments.

Changes:

• Modified the replica settings for the security-auditlog index to:

  {
    "index.number_of_shards": 1,
    "index.auto_expand_replicas": "0-1"
  }
  
  

Issues Resolved

• [BUG] Opensearch does not respect "discovery.type=single-node" setting during index creation #4739

Testing

• Created a single node cluster and verified that the security-auditlog index health changed from yellow to green.
• Confirmed that the new settings do not negatively impact multi-node clusters.

Check List

• New functionality includes testing
• New functionality has been documented
• New Roles/Permissions have a corresponding security dashboards plugin PR
• API changes companion pull request created
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
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[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 71.49%. Comparing base (1924e41) to head (e7bf71e).
Report is 22 commits behind head on main.

Files with missing lines	Patch %	Lines
.../auditlog/sink/AbstractInternalOpenSearchSink.java	50.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5030      +/-   ##
==========================================
- Coverage   71.50%   71.49%   -0.01%     
==========================================
  Files         336      336              
  Lines       22625    22643      +18     
  Branches     3598     3602       +4     
==========================================
+ Hits        16178    16189      +11     
- Misses       4648     4651       +3     
- Partials     1799     1803       +4     

Files with missing lines	Coverage Δ
...pensearch/security/auditlog/impl/AuditLogImpl.java	89.28% <100.00%> (ø)
.../security/auditlog/routing/AuditMessageRouter.java	81.60% <ø> (ø)
...uditlog/sink/InternalOpenSearchDataStreamSink.java	84.00% <100.00%> (+0.32%)	⬆️
...security/auditlog/sink/InternalOpenSearchSink.java	100.00% <100.00%> (ø)
...pensearch/security/auditlog/sink/SinkProvider.java	83.51% <100.00%> (+0.37%)	⬆️
.../auditlog/sink/AbstractInternalOpenSearchSink.java	70.96% <50.00%> (-5.04%)	⬇️

... and 23 files with indirect coverage changes