Handle uberjar scenario where the ES jdbc driver file is bundled

inside another jar file.

x-pack/plugin/sql/sql-client/src/main/java/org/elasticsearch/xpack/sql/client/Version.java

@@ -85,14 +85,16 @@ static byte[] from(String ver) {
 
         // This is similar to how Elasticsearch's Build class digs up its build information.
         // Since version info is not critical, the parsing is lenient
-        URL url = Version.class.getProtectionDomain().getCodeSource().getLocation();
-        String urlStr = url.toString();
+        CURRENT = extractVersion(Version.class.getProtectionDomain().getCodeSource().getLocation());
+    }
 
+    static Version extractVersion(URL url) {
+        String urlStr = url.toString();
         byte maj = 0, min = 0, rev = 0;
         String ver = "Unknown";
         String hash = ver;
 
-        if (urlStr.endsWith(".jar")) {
+        if (urlStr.endsWith(".jar") || urlStr.endsWith(".jar!/")) {
             try (JarInputStream jar = new JarInputStream(url.openStream())) {
                 Manifest manifest = jar.getManifest();
                 hash = manifest.getMainAttributes().getValue("Change");
@@ -105,7 +107,7 @@ static byte[] from(String ver) {
                 throw new IllegalArgumentException("Detected Elasticsearch JDBC jar but cannot retrieve its version", ex);
             }
         }
-        CURRENT = new Version(ver, hash, maj, min, rev);
+        return new Version(ver, hash, maj, min, rev);
     }
 
     @Override

x-pack/plugin/sql/sql-client/src/test/java/org/elasticsearch/xpack/sql/client/VersionTests.java

@@ -6,7 +6,17 @@
 package org.elasticsearch.xpack.sql.client;
 
 import org.elasticsearch.test.ESTestCase;
-import org.elasticsearch.xpack.sql.client.Version;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.jar.Attributes;
+import java.util.jar.JarEntry;
+import java.util.jar.JarOutputStream;
+import java.util.jar.Manifest;
 
 public class VersionTests extends ESTestCase {
     public void test70Version() {
@@ -43,4 +53,42 @@ public void testInvalidVersion() {
         IllegalArgumentException err = expectThrows(IllegalArgumentException.class, () -> Version.from("7.1"));
         assertEquals("Invalid version 7.1", err.getMessage());
     }
+
+    public void testVersionFromJarInJar() throws IOException {
+        Path dir = createTempDir();
+        Path jarPath = dir.resolve("foo.jar");
+        Path innerJarPath = dir.resolve("es-sql-jdbc.jar");
+
+        Manifest jdbcJarManifest = new Manifest();
+        Attributes attributes = jdbcJarManifest.getMainAttributes();
+        attributes.put(Attributes.Name.MANIFEST_VERSION, "1.0.0");
+        attributes.put(new Attributes.Name("Change"), "abc");
+        attributes.put(new Attributes.Name("X-Compile-Elasticsearch-Version"), "1.2.3");
+
+        try (JarOutputStream jdbc = new JarOutputStream(Files.newOutputStream(innerJarPath, StandardOpenOption.CREATE), jdbcJarManifest)) {}
+
+        try (BufferedInputStream in = new BufferedInputStream(Files.newInputStream(innerJarPath));
+                JarOutputStream out = new JarOutputStream(Files.newOutputStream(jarPath, StandardOpenOption.CREATE), new Manifest())) {
+            JarEntry entry = new JarEntry("es-sql-jdbc.jar!/");
+            out.putNextEntry(entry);
+
+            byte[] buffer = new byte[1024];
+            while (true) {
+                int count = in.read(buffer);
+                if (count == -1) {
+                    break;
+                }
+                out.write(buffer, 0, count);
+            }
+        }
+
+        URL jarInJar = new URL("jar:" + jarPath.toUri().toURL().toString() + "!/es-sql-jdbc.jar!/");
+
+        Version version = Version.extractVersion(jarInJar);
+        assertEquals(1, version.major);
+        assertEquals(2, version.minor);
+        assertEquals(3, version.revision);
+        assertEquals("abc", version.hash);
+        assertEquals("1.2.3", version.version);
+    }
 }