[Bug] Fix Build Metadata (opensearch-project#7817)

Refactoring Build to core library broke the build metadata. Test
coverage was insufficient to catch this bug. This commit fixes the
build metadata and improves test coverage such that any unexpected
metadata changes are caught.

Signed-off-by: Nicholas Walter Knize <nknize@apache.org>
Co-authored-by: Nicholas Walter Knize <nknize@apache.org>
Co-authored-by: Thomas Farr <tsfarr@amazon.com>

libs/core/src/main/java/org/opensearch/Build.java

@@ -114,12 +114,14 @@ public static Type fromDisplayName(final String displayName, final boolean stric
         // these are parsed at startup, and we require that we are able to recognize the values passed in by the startup scripts
         type = Type.fromDisplayName(System.getProperty("opensearch.distribution.type", "unknown"), true);
 
-        final String opensearchPrefix = distribution + "-" + Version.CURRENT;
+        final String opensearchPrefix = distribution;
         final URL url = getOpenSearchCodeSourceLocation();
         final String urlStr = url == null ? "" : url.toString();
         if (urlStr.startsWith("file:/")
-            && (urlStr.endsWith(opensearchPrefix + ".jar")
-                || urlStr.matches("(.*)" + opensearchPrefix + "(-)?((alpha|beta|rc)[0-9]+)?(-SNAPSHOT)?.jar"))) {
+            && (urlStr.endsWith(opensearchPrefix + "-" + Version.CURRENT + ".jar")
+                || urlStr.matches(
+                    "(.*)" + opensearchPrefix + "(-)?(.*?)" + Version.CURRENT + "(-)?((alpha|beta|rc)[0-9]+)?(-SNAPSHOT)?.jar"
+                ))) {
             try (JarInputStream jar = new JarInputStream(FileSystemUtils.openFileURLStream(url))) {
                 Manifest manifest = jar.getManifest();
                 hash = manifest.getMainAttributes().getValue("Change");

server/src/test/java/org/opensearch/BuildTests.java

@@ -60,9 +60,11 @@ public void testJarMetadata() throws IOException {
         URL url = Build.getOpenSearchCodeSourceLocation();
         // throws exception if does not exist, or we cannot access it
         try (InputStream ignored = FileSystemUtils.openFileURLStream(url)) {}
-        // these should never be null
+        // these should never be null or "unknown"
         assertNotNull(Build.CURRENT.date());
+        assertNotEquals(Build.CURRENT.date(), "unknown");
         assertNotNull(Build.CURRENT.hash());
+        assertNotEquals(Build.CURRENT.hash(), "unknown");
     }
 
     public void testIsProduction() {