Switch role pluggability to use SPI

plugins/examples/discovery-node-role-extension/build.gradle

@@ -0,0 +1,36 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+apply plugin: 'elasticsearch.testclusters'
+apply plugin: 'elasticsearch.esplugin'
+
+esplugin {
+  name 'discovery-node-role-extension'
+  description 'an example DiscoveryNodeRoleExtension'
+  classname 'org.elasticsearch.example.discovery_node_role_extension.AdditionalRolePlugin'
+  licenseFile rootProject.file('licenses/APACHE-LICENSE-2.0.txt')
+  noticeFile rootProject.file('NOTICE.txt')
+}
+
+testClusters.integTest {
+  setting 'node.additional', 'true'
+  testDistribution = 'OSS'
+}
+
+test.enabled = false

plugins/examples/discovery-node-role-extension/src/main/java/org/elasticsearch/example/discovery_node_role_extension/AdditionalRolePlugin.java

@@ -0,0 +1,56 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.example.discovery_node_role_extension;
+
+import org.elasticsearch.cluster.node.DiscoveryNodeRole;
+import org.elasticsearch.common.settings.Setting;
+import org.elasticsearch.plugins.Plugin;
+
+import java.util.List;
+import java.util.Set;
+
+public class AdditionalRolePlugin extends Plugin {
+
+    static final Setting<Boolean> NODE_ADDITIONAL_SETTING = Setting.boolSetting("node.additional", false, Setting.Property.NodeScope);
+
+    @Override
+    public List<Setting<?>> getSettings() {
+        return List.of(NODE_ADDITIONAL_SETTING);
+    }
+
+    public static DiscoveryNodeRole ADDITIONAL_ROLE = new DiscoveryNodeRole("additional", "a") {
+
+        @Override
+        protected Setting<Boolean> roleSetting() {
+            return NODE_ADDITIONAL_SETTING;
+        }
+
+    };
+
+    public static class DiscoveryNodeRoleExtension implements org.elasticsearch.cluster.node.DiscoveryNodeRoleExtension {
+
+        @Override
+        public Set<DiscoveryNodeRole> roles() {
+            return Set.of(ADDITIONAL_ROLE);
+        }
+
+    }
+
+}

plugins/examples/discovery-node-role-extension/src/main/resources/META-INF/services/org.elasticsearch.cluster.node.DiscoveryNodeRoleExtension

@@ -0,0 +1 @@
+org.elasticsearch.example.discovery_node_role_extension.AdditionalRolePlugin$DiscoveryNodeRoleExtension

plugins/examples/discovery-node-role-extension/src/test/java/org/elasticsearch/examples/discovery_node_role_extension/DiscoveryNodeRoleExtensionClientYamlTestSuiteIT.java

@@ -0,0 +1,38 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.examples.discovery_node_role_extension;
+
+import com.carrotsearch.randomizedtesting.annotations.Name;
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+import org.elasticsearch.test.rest.yaml.ClientYamlTestCandidate;
+import org.elasticsearch.test.rest.yaml.ESClientYamlSuiteTestCase;
+
+public class DiscoveryNodeRoleExtensionClientYamlTestSuiteIT extends ESClientYamlSuiteTestCase {
+
+    public DiscoveryNodeRoleExtensionClientYamlTestSuiteIT(@Name("yaml") final ClientYamlTestCandidate testCandidate) {
+        super(testCandidate);
+    }
+
+    @ParametersFactory
+    public static Iterable<Object[]> parameters() throws Exception {
+        return ESClientYamlSuiteTestCase.createParameters();
+    }
+
+}

plugins/examples/discovery-node-role-extension/src/test/resources/rest-api-spec/test/discovery_node_role_extension/10_basic.yml

@@ -0,0 +1,15 @@
+"additional role":
+    - skip:
+        reason: "contains"
+        features: contains
+
+    - do:
+        cluster.state: {}
+
+    # get master node id
+    - set: { master_node: master }
+
+    - do:
+        nodes.info: {}
+
+    - match: { nodes.$master.roles.0: "additional" }

server/src/main/java/org/elasticsearch/cluster/node/DiscoveryNode.java

@@ -37,11 +37,13 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.ServiceLoader;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 
 /**
@@ -456,20 +458,35 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
 
     private static Map<String, DiscoveryNodeRole> roleNameToPossibleRoles;
 
-    public static void setPossibleRoles(final Set<DiscoveryNodeRole> possibleRoles) {
+    public static Set<String> getPossibleRoleNames() {
+        return roleNameToPossibleRoles.keySet();
+    }
+
+    static {
+        setPossibleRoles(DiscoveryNodeRole.BUILT_IN_ROLES);
+    }
+
+    static void setPossibleRoles(final Set<DiscoveryNodeRole> possibleRoles) {
         final Map<String, DiscoveryNodeRole> roleNameToPossibleRoles =
-                possibleRoles.stream().collect(Collectors.toUnmodifiableMap(DiscoveryNodeRole::roleName, Function.identity()));
+            possibleRoles.stream().collect(Collectors.toUnmodifiableMap(DiscoveryNodeRole::roleName, Function.identity()));
         // collect the abbreviation names into a map to ensure that there are not any duplicate abbreviations
         final Map<String, DiscoveryNodeRole> roleNameAbbreviationToPossibleRoles = roleNameToPossibleRoles.values()
-                .stream()
-                .collect(Collectors.toUnmodifiableMap(DiscoveryNodeRole::roleNameAbbreviation, Function.identity()));
+            .stream()
+            .collect(Collectors.toUnmodifiableMap(DiscoveryNodeRole::roleNameAbbreviation, Function.identity()));
         assert roleNameToPossibleRoles.size() == roleNameAbbreviationToPossibleRoles.size() :
-                "roles by name [" + roleNameToPossibleRoles + "], roles by name abbreviation [" + roleNameAbbreviationToPossibleRoles + "]";
+            "roles by name [" + roleNameToPossibleRoles + "], roles by name abbreviation [" + roleNameAbbreviationToPossibleRoles + "]";
         DiscoveryNode.roleNameToPossibleRoles = roleNameToPossibleRoles;
     }
 
-    public static Set<String> getPossibleRoleNames() {
-        return roleNameToPossibleRoles.keySet();
+    public static void reloadSPI(final ClassLoader loader) {
+        for (final DiscoveryNodeRoleExtension extension : ServiceLoader.load(DiscoveryNodeRoleExtension.class, loader)) {
+            final Set<DiscoveryNodeRole> possibleRoles = Stream.concat(
+                roleNameToPossibleRoles.values().stream(),
+                extension.roles().stream())
+                .collect(Collectors.toUnmodifiableSet());
+            setPossibleRoles(possibleRoles);
+        }
+
     }
 
     /**

server/src/main/java/org/elasticsearch/cluster/node/DiscoveryNodeRoleExtension.java

@@ -0,0 +1,28 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.cluster.node;
+
+import java.util.Set;
+
+public interface DiscoveryNodeRoleExtension {
+
+    Set<DiscoveryNodeRole> roles();
+
+}

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

@@ -54,7 +54,6 @@
 import org.elasticsearch.cluster.metadata.MetaDataIndexUpgradeService;
 import org.elasticsearch.cluster.metadata.TemplateUpgradeService;
 import org.elasticsearch.cluster.node.DiscoveryNode;
-import org.elasticsearch.cluster.node.DiscoveryNodeRole;
 import org.elasticsearch.cluster.routing.BatchedRerouteService;
 import org.elasticsearch.cluster.routing.RerouteService;
 import org.elasticsearch.cluster.routing.allocation.DiskThresholdMonitor;
@@ -320,14 +319,6 @@ protected Node(final Environment initialEnvironment,
             this.pluginsService = new PluginsService(tmpSettings, initialEnvironment.configFile(), initialEnvironment.modulesFile(),
                 initialEnvironment.pluginsFile(), classpathPlugins);
             final Settings settings = pluginsService.updatedSettings();
-            final Set<DiscoveryNodeRole> possibleRoles = Stream.concat(
-                    DiscoveryNodeRole.BUILT_IN_ROLES.stream(),
-                    pluginsService.filterPlugins(Plugin.class)
-                            .stream()
-                            .map(Plugin::getRoles)
-                            .flatMap(Set::stream))
-                    .collect(Collectors.toSet());
-            DiscoveryNode.setPossibleRoles(possibleRoles);
             localNodeFactory = new LocalNodeFactory(settings, nodeEnvironment.nodeId());
 
             // create the environment based on the finalized (processed) view of the settings

server/src/main/java/org/elasticsearch/plugins/Plugin.java

@@ -23,7 +23,6 @@
 import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.IndexTemplateMetaData;
-import org.elasticsearch.cluster.node.DiscoveryNodeRole;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.component.LifecycleComponent;
 import org.elasticsearch.common.io.stream.NamedWriteable;
@@ -47,7 +46,6 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.function.UnaryOperator;
 
 /**
@@ -179,10 +177,6 @@ public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settings) {
      */
     public List<BootstrapCheck> getBootstrapChecks() { return Collections.emptyList(); }
 
-    public Set<DiscoveryNodeRole> getRoles() {
-        return Set.of();
-    }
-
     /**
      * Close the resources opened by this plugin.
      *

server/src/main/java/org/elasticsearch/plugins/PluginsService.java

@@ -31,6 +31,7 @@
 import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.cluster.node.info.PluginsAndModules;
 import org.elasticsearch.bootstrap.JarHell;
+import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.io.FileSystemUtils;
@@ -511,6 +512,7 @@ private Plugin loadBundle(Bundle bundle, Map<String, Plugin> loaded) {
             // note: already asserted above that extended plugins are loaded and extensible
             ExtensiblePlugin.class.cast(loaded.get(extendedPluginName)).reloadSPI(loader);
         }
+        DiscoveryNode.reloadSPI(loader);
 
         Class<? extends Plugin> pluginClass = loadPluginClass(bundle.plugin.getClassname(), loader);
         Plugin plugin = loadPlugin(pluginClass, settings, configPath);