[Extensions] Add DynamicActionRegistry to ActionModule

[dbwiddis]

Companion PR: SDK #588. This PR must be merged first.

Description

Adds a DynamicActionRegistry class and instance field to the ActionModule.

TransportAction classes from OpenSearch and plugins are instantiated during Node bootstrap and injected as singletons.

Extensions have the need to proxy actions between extensions. For example, job scheduler needs to invoke actions on Anomaly Detector extension; Anomaly Detector may need to invoke actions on Alerting Extension; et. al. This capability is currently implemented with a single ProxyAction which relays these invocations blindly.

This PR adds a registry for Extensions to register and unregister classes which extend ActionType and TransportAction at times other than bootstrap.

The benefit of using a subclass of TransportAction is that the client.execute() invocation processes these actions through ActionFilters. The first such filter processed is in the security plugin and this provides a single point of contact for future application of security features.

Inspiration for some of these features: #4460 (but I did it my way)

Description of functionality:

• On bootstrap, ActionModule creates an registry with two internal maps; one corresponds to the actions map obtained from the injector, which is immutable, and an empty registry for addition (and potentially removal) of extension actions
• During Extension initialization, the getActions() extension point will be handled on OpenSearch by the ExtensionTransportActionsHandler which will register (in the registry) a custom subclass of the ActionType containing the fully qualified class name of the action on the Extension
  • There is no current usage of the implemented "unregister" functionality, but the capability is provided for future "hot swap" functionality.
• When one extension (or OpenSearch or a plugin) wants to invoke an action on an extension, that will be handled by the NodeClient's client.execute() path. This path uses associated ActionFilters and the potential for future checks and security/identity integration.
• The execution of this TransportAction will send it to the Extension for further processing (TBD in Companion PR).

Issues Resolved

Fixes SDK #107.

Companion PR implements SDK #525.

SDK #525 could be implemented using the existing ProxyAction setup that this PR replaces, but I believe the benefits of funneling all requests through a single touch point is a significant benefit and combined these efforts.

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.
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[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/12578/
• CommitID: eea1a21
  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?

[peternied]

Nice! I like the steps forward to consolidating all actions together. I've put in some notes about coupling and how the abstraction could work a little differently that I think could be more flexible.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/12602/
• CommitID: 7893511
  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?

[cwperks]

If the action requires parameters then how will then be sent to the extension?

[dbwiddis]

The ExtensionAction here is just a subclass of ActionType which is an instance used as the key to a map. The value corresponding to this is an ExtensionTransportAction with the same name, that references the ExtensionActionRequest and ExtensionActionResponse classes.

That ExtensionActionRequest is how the details are communicated, with an action string (a fully qualified class name that the extension will match to one of its existing getAction() actions) and a byte array which will represent the parameters (serialized from the action's ActionRequest). Those will be serialized and deserialized consistently.... currently with Writeable but we'll probably switch to protobuf.

[cwperks]

+1 for protobufs

[peternied]

Thanks for the refactor 👍

[owaiskazi19]

Overall looks good @dbwiddis. Small ask: would love to see a design diagram for the workflow in the SDK repository. Since we are touching the ActionModule here would be great to get some eyes from @reta @nknize

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/12611/
• CommitID: 3829f15
  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/12612/
• CommitID: 7c8061e
  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/12616/
• CommitID: b22dcad
  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/12628/
• CommitID: a8f487a
  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/12629/
• CommitID: b1f7982
  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:

      1 org.opensearch.indices.replication.SegmentReplicationAllocationIT.testSingleIndexShardAllocation

• URL: https://build.ci.opensearch.org/job/gradle-check/12630/
• CommitID: fe5f5ff
  Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[codecov-commenter]

Codecov Report

Merging #6734 (3abbeb2) into main (5f81930) will decrease coverage by 0.05%.
The diff coverage is 79.34%.

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@@             Coverage Diff              @@
##               main    #6734      +/-   ##
============================================
- Coverage     70.74%   70.69%   -0.05%     
+ Complexity    59203    59195       -8     
============================================
  Files          4810     4809       -1     
  Lines        283487   283536      +49     
  Branches      40877    40885       +8     
============================================
- Hits         200543   200440     -103     
- Misses        66465    66624     +159     
+ Partials      16479    16472       -7     

Impacted Files	Coverage Δ
...nsions/action/RegisterTransportActionsRequest.java	85.00% <ø> (ø)
...ns/action/TransportActionRequestFromExtension.java	66.66% <0.00%> (-2.57%)	⬇️
...ava/org/opensearch/test/client/NoOpNodeClient.java	27.77% <ø> (ø)
...sions/action/ExtensionTransportActionsHandler.java	47.31% <57.14%> (-8.94%)	⬇️
.../opensearch/extensions/action/ExtensionAction.java	61.53% <61.53%> (ø)
...in/java/org/opensearch/client/node/NodeClient.java	71.42% <66.66%> (ø)
.../main/java/org/opensearch/action/ActionModule.java	97.83% <100.00%> (+0.73%)	⬆️
...a/org/opensearch/extensions/ExtensionsManager.java	45.45% <100.00%> (ø)
...rch/extensions/action/ExtensionActionResponse.java	100.00% <100.00%> (ø)
...ch/extensions/action/ExtensionTransportAction.java	37.50% <100.00%> (+37.50%)	⬆️
... and 1 more

... and 483 files with indirect coverage changes

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[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: SUCCESS ✅
• URL: https://build.ci.opensearch.org/job/gradle-check/12862/
• CommitID: c9c753c