Update gradle run to be able to fetch and run external plugins

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'