Version option should display if snapshot

We have a command-line flag -V or --version that can be used to display
the version of Elasticsearch. However, the version that we display does
not contain whether or not the version is a snapshot build. This commit
changes the behavior here so that if the build is a snapshot, that is
included in the version string.

Relates #25970

core/src/main/java/org/elasticsearch/Version.java

@@ -382,6 +382,10 @@ public class Version implements Comparable<Version> {
         return sb.toString();
     }
 
+    public static String displayVersion(final Version version, final boolean isSnapshot) {
+        return version + (isSnapshot ? "-SNAPSHOT" : "");
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) {

core/src/main/java/org/elasticsearch/bootstrap/Elasticsearch.java

@@ -24,6 +24,7 @@ import joptsimple.OptionSpec;
 import joptsimple.OptionSpecBuilder;
 import joptsimple.util.PathConverter;
 import org.elasticsearch.Build;
+import org.elasticsearch.Version;
 import org.elasticsearch.cli.EnvironmentAwareCommand;
 import org.elasticsearch.cli.ExitCodes;
 import org.elasticsearch.cli.Terminal;
@@ -97,7 +98,7 @@ class Elasticsearch extends EnvironmentAwareCommand {
             throw new UserException(ExitCodes.USAGE, "Positional arguments not allowed, found " + options.nonOptionArguments());
         }
         if (options.has(versionOption)) {
-            terminal.println("Version: " + org.elasticsearch.Version.CURRENT
+            terminal.println("Version: " + Version.displayVersion(Version.CURRENT, Build.CURRENT.isSnapshot())
                     + ", Build: " + Build.CURRENT.shortHash() + "/" + Build.CURRENT.date()
                     + ", JVM: " + JvmInfo.jvmInfo().version());
             return;

core/src/main/java/org/elasticsearch/node/Node.java

@@ -277,7 +277,7 @@ public class Node implements Closeable {
             final JvmInfo jvmInfo = JvmInfo.jvmInfo();
             logger.info(
                 "version[{}], pid[{}], build[{}/{}], OS[{}/{}/{}], JVM[{}/{}/{}/{}]",
-                displayVersion(Version.CURRENT, Build.CURRENT.isSnapshot()),
+                Version.displayVersion(Version.CURRENT, Build.CURRENT.isSnapshot()),
                 jvmInfo.pid(),
                 Build.CURRENT.shortHash(),
                 Build.CURRENT.date(),
@@ -515,19 +515,14 @@ public class Node implements Closeable {
         }
     }
 
-    // visible for testing
     static void warnIfPreRelease(final Version version, final boolean isSnapshot, final Logger logger) {
         if (!version.isRelease() || isSnapshot) {
             logger.warn(
                 "version [{}] is a pre-release version of Elasticsearch and is not suitable for production",
-                displayVersion(version, isSnapshot));
+                Version.displayVersion(version, isSnapshot));
         }
     }
 
-    private static String displayVersion(final Version version, final boolean isSnapshot) {
-        return version + (isSnapshot ? "-SNAPSHOT" : "");
-    }
-
     protected TransportService newTransportService(Settings settings, Transport transport, ThreadPool threadPool,
                                                    TransportInterceptor interceptor,
                                                    Function<BoundTransportAddress, DiscoveryNode> localNodeFactory,

core/src/test/java/org/elasticsearch/VersionTests.java

@@ -378,4 +378,16 @@ public class VersionTests extends ESTestCase {
         VersionTests.assertUnknownVersion(VERSION_5_1_0_UNRELEASED);
     }
 
+    public void testDisplayVersion() {
+        final Version version = randomVersion(random());
+        {
+            final String displayVersion = Version.displayVersion(version, true);
+            assertThat(displayVersion, equalTo(version.toString() + "-SNAPSHOT"));
+        }
+        {
+            final String displayVersion = Version.displayVersion(version, false);
+            assertThat(displayVersion, equalTo(version.toString()));
+        }
+    }
+
 }

core/src/test/java/org/elasticsearch/bootstrap/ElasticsearchCliTests.java

@@ -63,7 +63,7 @@ public class ElasticsearchCliTests extends ESElasticsearchCliTestCase {
 
     private void runTestThatVersionIsReturned(String... args) throws Exception {
         runTestVersion(ExitCodes.OK, output -> {
-            assertThat(output, containsString("Version: " + Version.CURRENT.toString()));
+            assertThat(output, containsString("Version: " + Version.displayVersion(Version.CURRENT, Build.CURRENT.isSnapshot())));
             assertThat(output, containsString("Build: " + Build.CURRENT.shortHash() + "/" + Build.CURRENT.date()));
             assertThat(output, containsString("JVM: " + JvmInfo.jvmInfo().version()));
         }, args);