Support downloading pre-built SNAPSHOT artifacts for BWC tests

Add a -Dbwc.useSnapshots=true flag that downloads pre-built SNAPSHOT
artifacts from artifacts.opensearch.org for unreleased versions instead
of checking out git branches and compiling from source. The default
behavior is unchanged.

Signed-off-by: Andrew Ross <andrross@amazon.com>

Author: andrross

buildSrc/src/main/java/org/opensearch/gradle/BwcVersions.java

@@ -193,6 +193,18 @@ public UnreleasedVersionInfo unreleasedInfo(Version version) {
         return unreleased.get(version);
     }
 
+    /**
+     * Returns the version string for use in distribution resolution. When {@code bwc.useSnapshots}
+     * is set, unreleased versions get a "-SNAPSHOT" suffix so they resolve from the snapshot
+     * artifact repository instead of being built from source.
+     */
+    public String versionString(Version version) {
+        if (Boolean.parseBoolean(System.getProperty("bwc.useSnapshots", "false")) && unreleased.containsKey(version)) {
+            return version + "-SNAPSHOT";
+        }
+        return version.toString();
+    }
+
     public void forPreviousUnreleased(Consumer<UnreleasedVersionInfo> consumer) {
         List<UnreleasedVersionInfo> collect = getUnreleased().stream()
             .filter(version -> version.equals(currentVersion) == false)

buildSrc/src/main/java/org/opensearch/gradle/internal/InternalDistributionDownloadPlugin.java

@@ -98,6 +98,10 @@ private void registerInternalDistributionResolutions(NamedDomainObjectContainer<
         }));
 
         resolutions.register("bwc", distributionResolution -> distributionResolution.setResolver((project, distribution) -> {
+            // When bwc.useSnapshots is set, skip local builds and download pre-built SNAPSHOT artifacts instead
+            if (Boolean.parseBoolean(System.getProperty("bwc.useSnapshots", "false"))) {
+                return null;
+            }
             BwcVersions.UnreleasedVersionInfo unreleasedInfo = bwcVersions.unreleasedInfo(Version.fromString(distribution.getVersion()));
             if (unreleasedInfo != null) {
                 if (distribution.getBundledJdk() == JavaPackageType.NONE) {

qa/full-cluster-restart/build.gradle

@@ -44,7 +44,7 @@ for (Version bwcVersion : BuildParams.bwcVersions.indexCompatible) {
 
   testClusters {
     "${baseName}" {
-      versions = [bwcVersion.toString(), project.version]
+      versions = [BuildParams.bwcVersions.versionString(bwcVersion), project.version]
       numberOfNodes = 2
       // some tests rely on the translog not being flushed
       setting 'indices.memory.shard_inactive_time', '60m'

qa/mixed-cluster/build.gradle

@@ -61,7 +61,7 @@ for (Version bwcVersion : BuildParams.bwcVersions.wireCompatible) {
      the nodes has a different minor.  */
   testClusters {
     "${baseName}" {
-      versions = [bwcVersion.toString(), project.version]
+      versions = [BuildParams.bwcVersions.versionString(bwcVersion), project.version]
       numberOfNodes = 4
 
       setting 'path.repo', "${buildDir}/cluster/shared/repo/${baseName}"

qa/repository-multi-version/build.gradle

@@ -54,7 +54,7 @@ for (Version bwcVersion : BuildParams.bwcVersions.indexCompatible) {
   }
 
   testClusters {
-    "${oldClusterName}" clusterSettings(bwcVersion.toString())
+    "${oldClusterName}" clusterSettings(BuildParams.bwcVersions.versionString(bwcVersion))
     "${newClusterName}" clusterSettings(project.version)
   }
 

qa/rolling-upgrade/build.gradle

@@ -56,7 +56,7 @@ for (Version bwcVersion : BuildParams.bwcVersions.wireCompatible) {
 
   testClusters {
     "${baseName}" {
-      versions = [bwcVersionStr, project.version]
+      versions = [BuildParams.bwcVersions.versionString(bwcVersion), project.version]
       numberOfNodes = 3
 
       setting 'repositories.url.allowed_urls', 'http://snapshot.test*'

qa/verify-version-constants/build.gradle

@@ -42,7 +42,7 @@ for (Version bwcVersion : BuildParams.bwcVersions.indexCompatible) {
 
   testClusters {
     "${baseName}" {
-      version = bwcVersion.toString()
+      version = BuildParams.bwcVersions.versionString(bwcVersion)
       setting 'http.content_type.required', 'true'
     }
   }