Adding replication (CCR) plugin interface and classes to common-utils

[aggarwalShivani]

Description

Background:

• This change is required for a new feature being added in ism plugin - unfollow-action #726 - integrating ccr and ism plugins.
• For this feature, ism plugin needs to invoke stop-replication action from ccr. As both ccr and ism need to invoke some common code, the common code can be moved to common-utils, as done previously for other plugins too. For ex. notifications plugin
• As sharing of libraries also leads to a type-cast and class-loading issue - previously seen with notification plugin - the request object needs to be of a higher-level class from opensearch-core like ActionRequest and later be recreated into required type i.e. StopIndexReplicationRequest.

Proposed Solution:

1. Common-utils: Move common code of stop-replication from ccr project to common-utils.
2. CCR: Modify ccr plugin to consume classes from common-utils. Also, create a new TransportAction that transforms the request into required type and invokes TransportStopIndexReplicationAction.
3. ISM: Add new action in ism
   (FYI - This is an alternative approach for this feature. I had also raised a draft PR with a different approach, but we didnt go ahead with it as it required changes in opensearch-core as well.)

Change description:
Code for StopIndexReplicationRequest and StopIndexReplicationAction are moved to common-utils. Added UTs for both the new classes added.
This PR caters to point 1 of the proposed solution.

Issues Resolved

Related Issues
unfollow-action #726

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

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.

[aggarwalShivani]

Hi,
For this change, some CI failures are due to AcknowledgedResponse moving to org.opensearch.action.support.clustermanager. Will repush once the integration issue with common-utils, ccr, ism on main branch is resolved
As discussed with @bowenlan-amzn, raised backport PR on 2.x branch (#789).

[aggarwalShivani]

Hi, For this change, some CI failures are due to AcknowledgedResponse moving to org.opensearch.action.support.clustermanager. Will repush once the integration issue with common-utils, ccr, ism on main branch is resolved As discussed with @bowenlan-amzn, raised backport PR on 2.x branch (#789).

Hi @bowenlan-amzn

The integration issue of common-utils and ccr is resolved with the merge of this change in ccr.
ISM continues to remain blocked though until this issue is resolved.

Meanwhile, as the changes for the stop-replication feature for both common-utlis and ccr are ready, requesting your review on this.
Backport PR is also ready for review #789

[bowenlan-amzn]

Suggested change

	open class ReplicationPluginInterface {
	object ReplicationPluginInterface {

[bowenlan-amzn]

Feels like the methods here should just be static methods.

[aggarwalShivani]

Thanks. After modifying the way UTs were written in ism, it didnt need to remain open anymore.
I've made this change now 👍

On 2.x branch, as the backport PR was already merged, I've raised a new PR for addressing this comment.

[aggarwalShivani]

Hi @bowenlan-amzn
This change is ready for review, kindly review when possible. Once this gets merged, CI checks for the ccr and ism PRs could go through :)

[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:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/common-utils/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/common-utils/backport-2.x
# Create a new branch
git switch --create backport-667-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 5e086a27ef844584499fdc15d7c15c9b47ad4420
# Push it to GitHub
git push --set-upstream origin backport-667-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/common-utils/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport-667-to-2.x.