[META] Migrate to elasticsearch StableAPI

[yaauie]

In Elasticsearch core we introduced StableAPIBridge so that Logstash can rely on unchanging code (elastic/elasticsearch#108171), but we need to migrate to the stable wrappers to gain the benefit and stabilize our reliance on Elasticsearch internals.

Number of sequential tasks:

• Elasticsearch scope: evaluate current status of Stable API based on plugin usage

  • introduce bridge API for ProjectId: it recently came into play (with this change)
  • introduce bridge API for org.elasticsearch.core.Releasable (used by IntegrationBatch.java): it seems it was missed
  • introduce bridge API for org.elasticsearch.action.support.RefCountingRunnable (used by EventProcessor.java): it seems it was missed
  • introduce bridge API for org.elasticsearch.ingest.common.FailProcessorException: it seems it was missed

• Plugin scope: make Bridge API available in the plugin

  • the plugin builds minimal Elasticsearch (with gradlew localDistro) so logstash-bridge will not be built during this process. We need to have a task to build the module (./gradlew :libs:logstash-bridge:build) and add (shade like we have shadeElasticsearchIngestGeoIpModule) the module as a dependency to the project.

• Elasticsearch scope: Came from evaluation task that we need to introduce modular descriptors for the redact, wildcard & spatial plugins to make them available in logstash-bridge

• Plugin scope: move to Bridge API

  • Replace all classes with its bridges (e.g: Settings -> SettingsBridge)
  • Consider simplifications: some of the classes such as ScriptService has simplification logics so that plugin can remove unnecessary logica and utilize them. I will add more specific details once I start working on this.

• Elasticsearch scope: Based on the evaluate current status of Stable API investigation outcome, introduce or modify the wrapper(s)

  • Migrate all Bridges to "interface pattern", using factory methods instead of constructors.
  • Extract implementations to package-private (so that we have a clear boundary of what is "externalized" to the logstash plugin

• Elasticsearch scope: introduce Bridge and proxies for GeoIP

  • include geoip ingest module to logstash-bridge (somehow commented compileOnly project(':modules:ingest-geoip'))

• Plugin scope: move GeoIP to Bridge API

• Elasticsearch scope: deprecate/remove if unused classes left

  • Such as LogstashInternalBridge will be no longer used by the plugin but used internally in the bridge, do we need to replace and remove?!

[mashhurs]

Closing this issue since all planned works delivered.