Merge changes from topic "ES-6.5-discontinued" into stable-2.16

* changes:
  ElasticContainer: Upgrade V6_8 to elasticsearch 6.8.9
  ElasticVersion: Replace unchecked throw w/ javadoc
  Elasticsearch: Remove support for EOL 6.5 version

Documentation/config-gerrit.txt

@@ -3208,11 +3208,6 @@ Note that the same username and password are used for all servers.
 
 For further information about Elasticsearch security, please refer to the documentation:
 
-* link:https://www.elastic.co/guide/en/x-pack/5.6/security-getting-started.html[Elasticsearch 5.6]
-* link:https://www.elastic.co/guide/en/x-pack/6.2/security-getting-started.html[Elasticsearch 6.2]
-* link:https://www.elastic.co/guide/en/elastic-stack-overview/6.3/security-getting-started.html[Elasticsearch 6.3]
-* link:https://www.elastic.co/guide/en/elastic-stack-overview/6.4/security-getting-started.html[Elasticsearch 6.4]
-* link:https://www.elastic.co/guide/en/elastic-stack-overview/6.5/security-getting-started.html[Elasticsearch 6.5]
 * link:https://www.elastic.co/guide/en/elastic-stack-overview/6.6/security-getting-started.html[Elasticsearch 6.6]
 
 [[elasticsearch.username]]elasticsearch.username::

java/com/google/gerrit/elasticsearch/ElasticVersion.java

@@ -18,7 +18,6 @@ import com.google.common.base.Joiner;
 import java.util.regex.Pattern;
 
 public enum ElasticVersion {
-  V6_5("6.5.*"),
   V6_6("6.6.*"),
   V6_7("6.7.*"),
   V6_8("6.8.*"),
@@ -48,7 +47,14 @@ public enum ElasticVersion {
     }
   }
 
-  public static ElasticVersion forVersion(String version) throws UnsupportedVersion {
+  /**
+   * Convert a version String to an ElasticVersion if supported.
+   *
+   * @param version for which to return an ElasticVersion
+   * @return the corresponding ElasticVersion if supported
+   * @throws UnsupportedVersion
+   */
+  public static ElasticVersion forVersion(String version) {
     for (ElasticVersion value : ElasticVersion.values()) {
       if (value.pattern.matcher(version).matches()) {
         return value;

javatests/com/google/gerrit/elasticsearch/ElasticContainer.java

@@ -38,14 +38,12 @@ public class ElasticContainer extends ElasticsearchContainer {
 
   private static String getImageName(ElasticVersion version) {
     switch (version) {
-      case V6_5:
-        return "blacktop/elasticsearch:6.5.4";
       case V6_6:
         return "blacktop/elasticsearch:6.6.2";
       case V6_7:
         return "blacktop/elasticsearch:6.7.2";
       case V6_8:
-        return "blacktop/elasticsearch:6.8.8";
+        return "blacktop/elasticsearch:6.8.9";
       case V7_0:
         return "blacktop/elasticsearch:7.0.1";
       case V7_1:

javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java

@@ -25,9 +25,6 @@ public class ElasticVersionTest {
 
   @Test
   public void supportedVersion() throws Exception {
-    assertThat(ElasticVersion.forVersion("6.5.0")).isEqualTo(ElasticVersion.V6_5);
-    assertThat(ElasticVersion.forVersion("6.5.1")).isEqualTo(ElasticVersion.V6_5);
-
     assertThat(ElasticVersion.forVersion("6.6.0")).isEqualTo(ElasticVersion.V6_6);
     assertThat(ElasticVersion.forVersion("6.6.1")).isEqualTo(ElasticVersion.V6_6);
 
@@ -69,7 +66,6 @@ public class ElasticVersionTest {
 
   @Test
   public void atLeastMinorVersion() throws Exception {
-    assertThat(ElasticVersion.V6_5.isAtLeastMinorVersion(ElasticVersion.V6_7)).isFalse();
     assertThat(ElasticVersion.V6_6.isAtLeastMinorVersion(ElasticVersion.V6_7)).isFalse();
     assertThat(ElasticVersion.V6_7.isAtLeastMinorVersion(ElasticVersion.V6_7)).isTrue();
     assertThat(ElasticVersion.V6_8.isAtLeastMinorVersion(ElasticVersion.V6_8)).isTrue();
@@ -84,7 +80,6 @@ public class ElasticVersionTest {
 
   @Test
   public void version6OrLater() throws Exception {
-    assertThat(ElasticVersion.V6_5.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V6_6.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V6_7.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V6_8.isV6OrLater()).isTrue();
@@ -99,7 +94,6 @@ public class ElasticVersionTest {
 
   @Test
   public void version7OrLater() throws Exception {
-    assertThat(ElasticVersion.V6_5.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V6_6.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V6_7.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V6_8.isV7OrLater()).isFalse();