[Extensions] Add ExtensionAwarePlugin extension point to add custom settings for extensions

[cwperks]

Description

This creates a new extension point inside of IdentityPlugin called getExtensionSettings that allows this singular plugin to define settings that should be placed in extensions.yml that are needed for security. This creates a new scope for settings called the Extension scope that means that these particular settings should be placed in extensions.yml and pertain to an extension. I first implemented this without using scoped settings, but ultimately chose to use Scoped Settings similar to get Plugin.getSettings() works. Using ScopeSettings, defaults can be assigned to the settings within the implementation of the getExtensionSettings() method.

Related Issues

opensearch-project/security#2746

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff
• Commit changes are listed out in CHANGELOG.md file (See: Changelog)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/15247/
• CommitID: 9717fd6
  Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/15248/
• CommitID: 72bb099
  Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/15266/
• CommitID: 531447f
  Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green.
  Is the failure a flaky test unrelated to your change?

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      2 org.opensearch.remotestore.RemoteStoreRefreshListenerIT.testRemoteRefreshRetryOnFailure
      1 org.opensearch.smoketest.SmokeTestMultiNodeClientYamlTestSuiteIT.test {yaml=pit/10_basic/Delete all}

• URL: https://build.ci.opensearch.org/job/gradle-check/16091/
• CommitID: e588b22
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[owaiskazi19]

Since security is a plugin for OpenSearch. This design LGTM! Later, if we decide security to be an extension we can utilize getSettings extension point from SDK to register the settings coming from security.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      1 org.opensearch.remotestore.RemoteStoreRefreshListenerIT.testRemoteRefreshRetryOnFailure
      1 org.opensearch.indices.replication.SegmentReplicationIT.testReplicationPostDeleteAndForceMerge

• URL: https://build.ci.opensearch.org/job/gradle-check/16119/
• CommitID: 1d1273f
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[owaiskazi19]

LGTM! Thanks @cwperks for the changes!

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: UNSTABLE ❕
• TEST FAILURES:

      1 org.opensearch.remotestore.RemoteStoreRefreshListenerIT.testRemoteRefreshRetryOnFailure

• URL: https://build.ci.opensearch.org/job/gradle-check/16122/
• CommitID: 9aa929c
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[cwperks]

@owaiskazi19 @reta Can this be merged if there are no outstanding questions? This should be backported to 2.x.

[reta]

@owaiskazi19 @reta Can this be merged if there are no outstanding questions? This should be backported to 2.x.

The merge is blocked by unresolved conversations, could you please resolve them? Thank you.

[cwperks]

All comments have now been marked as resolved

[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/backport-2.x
# Create a new branch
git switch --create backport/backport-7526-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 277eb3d59fb9edcae8575577ec135032e3563f2e
# Push it to GitHub
git push --set-upstream origin backport/backport-7526-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-7526-to-2.x.

[reta]

@cwperks may need manual backport sadly ...

[cwperks]

On it

[cwperks]

Opened up backport PR: #7756