org.elasticsearch.plugins.ActionPlugin Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* 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.plugins;
import org.elasticsearch.action.ActionType;
import org.elasticsearch.action.ActionRequest;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.action.RequestValidators;
import org.elasticsearch.action.admin.indices.alias.IndicesAliasesRequest;
import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
import org.elasticsearch.action.support.ActionFilter;
import org.elasticsearch.action.support.TransportAction;
import org.elasticsearch.action.support.TransportActions;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.settings.ClusterSettings;
import org.elasticsearch.common.settings.IndexScopedSettings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.settings.SettingsFilter;
import org.elasticsearch.common.util.concurrent.ThreadContext;
import org.elasticsearch.rest.RestController;
import org.elasticsearch.rest.RestHandler;
import org.elasticsearch.rest.RestHeaderDefinition;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.function.Supplier;
import java.util.function.UnaryOperator;
import java.util.stream.Collectors;
/**
* An additional extension point for {@link Plugin}s that extends Elasticsearch's scripting functionality. Implement it like this:
* {@code
* {@literal @}Override
* public List> getActions() {
* return Arrays.asList(new ActionHandler<>(ReindexAction.INSTANCE, TransportReindexAction.class),
* new ActionHandler<>(UpdateByQueryAction.INSTANCE, TransportUpdateByQueryAction.class),
* new ActionHandler<>(DeleteByQueryAction.INSTANCE, TransportDeleteByQueryAction.class),
* new ActionHandler<>(RethrottleAction.INSTANCE, TransportRethrottleAction.class));
* }
* }
*/
public interface ActionPlugin {
/**
* Actions added by this plugin.
*/
default List> getActions() {
return Collections.emptyList();
}
/**
* Client actions added by this plugin. This defaults to all of the {@linkplain ActionType} in
* {@linkplain ActionPlugin#getActions()}.
*/
default List> getClientActions() {
return getActions().stream().map(a -> a.action).collect(Collectors.toList());
}
/**
* ActionType filters added by this plugin.
*/
default List getActionFilters() {
return Collections.emptyList();
}
/**
* Rest handlers added by this plugin.
*/
default List getRestHandlers(Settings settings, RestController restController, ClusterSettings clusterSettings,
IndexScopedSettings indexScopedSettings, SettingsFilter settingsFilter,
IndexNameExpressionResolver indexNameExpressionResolver, Supplier nodesInCluster) {
return Collections.emptyList();
}
/**
* Returns headers which should be copied through rest requests on to internal requests.
*/
default Collection getRestHeaders() {
return Collections.emptyList();
}
/**
* Returns headers which should be copied from internal requests into tasks.
*/
default Collection getTaskHeaders() {
return Collections.emptyList();
}
/**
* Returns a function used to wrap each rest request before handling the request.
* The returned {@link UnaryOperator} is called for every incoming rest request and receives
* the original rest handler as it's input. This allows adding arbitrary functionality around
* rest request handlers to do for instance logging or authentication.
* A simple example of how to only allow GET request is here:
*
* {@code
* UnaryOperator getRestHandlerWrapper(ThreadContext threadContext) {
* return originalHandler -> (RestHandler) (request, channel, client) -> {
* if (request.method() != Method.GET) {
* throw new IllegalStateException("only GET requests are allowed");
* }
* originalHandler.handleRequest(request, channel, client);
* };
* }
* }
*
*
* Note: Only one installed plugin may implement a rest wrapper.
*/
default UnaryOperator getRestHandlerWrapper(ThreadContext threadContext) {
return null;
}
final class ActionHandler {
private final ActionType action;
private final Class> transportAction;
private final Class[] supportTransportActions;
/**
* Create a record of an action, the {@linkplain TransportAction} that handles it, and any supporting {@linkplain TransportActions}
* that are needed by that {@linkplain TransportAction}.
*/
public ActionHandler(ActionType action, Class> transportAction,
Class... supportTransportActions) {
this.action = action;
this.transportAction = transportAction;
this.supportTransportActions = supportTransportActions;
}
public ActionType getAction() {
return action;
}
public Class> getTransportAction() {
return transportAction;
}
public Class[] getSupportTransportActions() {
return supportTransportActions;
}
@Override
public String toString() {
StringBuilder b = new StringBuilder().append(action.name()).append(" is handled by ").append(transportAction.getName());
if (supportTransportActions.length > 0) {
b.append('[').append(Strings.arrayToCommaDelimitedString(supportTransportActions)).append(']');
}
return b.toString();
}
@Override
public boolean equals(Object obj) {
if (obj == null || obj.getClass() != ActionHandler.class) {
return false;
}
ActionHandler other = (ActionHandler) obj;
return Objects.equals(action, other.action)
&& Objects.equals(transportAction, other.transportAction)
&& Objects.deepEquals(supportTransportActions, other.supportTransportActions);
}
@Override
public int hashCode() {
return Objects.hash(action, transportAction, supportTransportActions);
}
}
/**
* Returns a collection of validators that are used by {@link RequestValidators} to validate a
* {@link org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest} before the executing it.
*/
default Collection> mappingRequestValidators() {
return Collections.emptyList();
}
default Collection> indicesAliasesRequestValidators() {
return Collections.emptyList();
}
}