Update gradle run to be able to fetch and run external plugins (opensearch-project#19428)

* Update installedPlugins in run.gradle to fetch plugins from maven.

This change allows us to install  plugins not shipped with core with gradlew run.
It supports simply specifying the plugin name or adding a specific version.

Example:
./gradlew run -PinstalledPlugins['opensearch-job-scheduler'] or
./gradlew run -PinstalledPlugins['opensearch-job-scheduler:3.2.x.x]

Signed-off-by: Marc Handalian <[email protected]>

* Add support for third party plugins

Signed-off-by: Marc Handalian <[email protected]>

---------

Signed-off-by: Marc Handalian <[email protected]>

Author: mch2

DEVELOPER_GUIDE.md

@@ -76,9 +76,9 @@ Fork [opensearch-project/OpenSearch](https://github.com/opensearch-project/OpenS
 
 #### JDK
 
-OpenSearch recommends building with the [Temurin/Adoptium](https://adoptium.net/temurin/releases/) distribution. JDK 11 is the minimum supported, and JDK-24 is the newest supported. You must have a supported JDK installed with the environment variable `JAVA_HOME` referencing the path to Java home for your JDK installation, e.g. `JAVA_HOME=/usr/lib/jvm/jdk-21`. 
+OpenSearch recommends building with the [Temurin/Adoptium](https://adoptium.net/temurin/releases/) distribution. JDK 11 is the minimum supported, and JDK-24 is the newest supported. You must have a supported JDK installed with the environment variable `JAVA_HOME` referencing the path to Java home for your JDK installation, e.g. `JAVA_HOME=/usr/lib/jvm/jdk-21`.
 
-Download Java 11 from [here](https://adoptium.net/releases.html?variant=openjdk11). 
+Download Java 11 from [here](https://adoptium.net/releases.html?variant=openjdk11).
 
 
 In addition, certain backward compatibility tests check out and compile the previous major version of OpenSearch, and therefore require installing [JDK 11](https://adoptium.net/temurin/releases/?version=11) and [JDK 17](https://adoptium.net/temurin/releases/?version=17) and setting the `JAVA11_HOME` and `JAVA17_HOME` environment variables. More to that, since 8.10 release, Gradle has deprecated the usage of the any JDKs below JDK-16. For smooth development experience, the recommendation is to install at least [JDK 17](https://adoptium.net/temurin/releases/?version=17) or [JDK 21](https://adoptium.net/temurin/releases/?version=21). If you still want to build with JDK-11 only, please add `-Dorg.gradle.warning.mode=none` when invoking any Gradle build task from command line, for example:
@@ -178,6 +178,23 @@ Run OpenSearch using `gradlew run`.
 ./gradlew run -PinstalledPlugins="['plugin1', 'plugin2']"
 ```
 
+External plugins may also be fetched and installed from maven snapshots:
+
+```bash
+./gradlew run -PinstalledPlugins="['opensearch-job-scheduler', 'opensearch-sql-plugin']"
+```
+
+You can specify a plugin version to pull to test a specific version in the org.opensearch.plugin groupId:
+```bash
+./gradlew run -PinstalledPlugins="['opensearch-job-scheduler:3.3.x.x']"
+```
+
+or install with fully qualified maven coordinates:
+```bash
+./gradlew run -PinstalledPlugins="['com.example:my-cool-plugin:3.3.x.x']"
+```
+
+
 That will build OpenSearch and start it, writing its log above Gradle's status message. We log a lot of stuff on startup, specifically these lines tell you that OpenSearch is ready.
 
 ```

gradle/run.gradle

@@ -28,6 +28,7 @@
  * under the License.
  */
 import org.opensearch.gradle.testclusters.RunTask
+import org.opensearch.gradle.VersionProperties
 
 apply plugin: 'opensearch.testclusters'
 
@@ -41,8 +42,45 @@ testClusters {
     if (numNodes > 1) numberOfNodes = numNodes
     if (findProperty("installedPlugins")) {
       installedPlugins = Eval.me(installedPlugins)
+
+      def resolveMavenPlugin = { coords ->
+        // Add default groupId if not fully qualified (less than 2 colons)
+        String[] parts = coords.split(':')
+        if (parts.length == 2 && parts[0].contains('.')) {
+          throw new IllegalArgumentException("version is required if groupdId is specified '${coords}' Use format: groupId:artifactId:version")
+        }
+        String fullCoords = parts.length < 3 ? 'org.opensearch.plugin:' + coords : coords
+        def config = project.configurations.detachedConfiguration(
+          project.dependencies.create(fullCoords)
+        )
+        config.resolutionStrategy.cacheChangingModulesFor 0, 'seconds'
+        plugin(project.layout.file(project.provider { config.singleFile }))
+      }
+
       for (String p : installedPlugins) {
-        plugin('plugins:'.concat(p))
+        // check if its a local plugin first
+        if (project.findProject(':plugins:' + p) != null) {
+          plugin('plugins:' + p)
+        } else {
+          // attempt to fetch it from maven
+          project.repositories.mavenLocal()
+          project.repositories {
+            maven {
+              name = 'OpenSearch Snapshots'
+              url = 'https://central.sonatype.com/repository/maven-snapshots/'
+            }
+          }
+          if (p.contains(':')) {
+            // Maven coordinates with version specified
+            String coords = p.contains('@') ? p : (p + '@zip')
+            resolveMavenPlugin(coords)
+          } else {
+            // Not found locally, try Maven with current OS version + 0
+            String version = VersionProperties.getOpenSearch().replace('-SNAPSHOT', '.0-SNAPSHOT')
+            String coords = p + ':' + version + '@zip'
+            resolveMavenPlugin(coords)
+          }
+        }
         if (p.equals("arrow-flight-rpc")) {
           // Add system properties for Netty configuration
           systemProperty 'io.netty.allocator.numDirectArenas', '1'