org.elasticsearch.action.admin.indices.alias.get.TransportGetAliasesAction Maven / Gradle / Ivy

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/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */
package org.elasticsearch.action.admin.indices.alias.get;

import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.master.TransportMasterNodeReadAction;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.block.ClusterBlockException;
import org.elasticsearch.cluster.block.ClusterBlockLevel;
import org.elasticsearch.cluster.metadata.AliasMetadata;
import org.elasticsearch.cluster.metadata.IndexMetadata;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.collect.ImmutableOpenMap;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.logging.DeprecationLogger;
import org.elasticsearch.common.util.concurrent.ThreadContext;
import org.elasticsearch.indices.SystemIndices;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportService;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Collectors;

public class TransportGetAliasesAction extends TransportMasterNodeReadAction {
    private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(TransportGetAliasesAction.class);

    private final SystemIndices systemIndices;

    @Inject
    public TransportGetAliasesAction(TransportService transportService, ClusterService clusterService,
                                     ThreadPool threadPool, ActionFilters actionFilters,
                                     IndexNameExpressionResolver indexNameExpressionResolver, SystemIndices systemIndices) {
        super(GetAliasesAction.NAME, transportService, clusterService, threadPool, actionFilters, GetAliasesRequest::new,
            indexNameExpressionResolver, GetAliasesResponse::new, ThreadPool.Names.SAME);
        this.systemIndices = systemIndices;
    }

    @Override
    protected ClusterBlockException checkBlock(GetAliasesRequest request, ClusterState state) {
        // Resolve with system index access since we're just checking blocks
        return state.blocks().indicesBlockedException(ClusterBlockLevel.METADATA_READ,
            indexNameExpressionResolver.concreteIndexNamesWithSystemIndexAccess(state, request));
    }

    @Override
    protected void masterOperation(GetAliasesRequest request, ClusterState state, ActionListener listener) {
        String[] concreteIndices;
        // Switch to a context which will drop any deprecation warnings, because there may be indices resolved here which are not
        // returned in the final response. We'll add warnings back later if necessary in checkSystemIndexAccess.
        try (ThreadContext.StoredContext ignore = threadPool.getThreadContext().newStoredContext(false)) {
            concreteIndices = indexNameExpressionResolver.concreteIndexNames(state, request);
        }
        final boolean systemIndexAccessAllowed = indexNameExpressionResolver.isSystemIndexAccessAllowed();
        ImmutableOpenMap> aliases = state.metadata().findAliases(request, concreteIndices);
        listener.onResponse(new GetAliasesResponse(postProcess(request, concreteIndices, aliases, state,
            systemIndexAccessAllowed, systemIndices)));
    }

    /**
     * Fills alias result with empty entries for requested indices when no specific aliases were requested.
     */
    static ImmutableOpenMap> postProcess(GetAliasesRequest request, String[] concreteIndices,
                                                                     ImmutableOpenMap> aliases,
                                                                     ClusterState state, boolean systemIndexAccessAllowed,
                                                                     SystemIndices systemIndices) {
        boolean noAliasesSpecified = request.getOriginalAliases() == null || request.getOriginalAliases().length == 0;
        ImmutableOpenMap.Builder> mapBuilder = ImmutableOpenMap.builder(aliases);
        for (String index : concreteIndices) {
            if (aliases.get(index) == null && noAliasesSpecified) {
                List previous = mapBuilder.put(index, Collections.emptyList());
                assert previous == null;
            }
        }
        final ImmutableOpenMap> finalResponse = mapBuilder.build();
        if (systemIndexAccessAllowed == false) {
            checkSystemIndexAccess(request, systemIndices, state, finalResponse);
        }
        return finalResponse;
    }

    private static void checkSystemIndexAccess(GetAliasesRequest request, SystemIndices systemIndices, ClusterState state,
                                               ImmutableOpenMap> aliasesMap) {
        List systemIndicesNames = new ArrayList<>();
        for (Iterator it = aliasesMap.keysIt(); it.hasNext(); ) {
            String indexName = it.next();
            IndexMetadata index = state.metadata().index(indexName);
            if (index != null && index.isSystem()) {
                systemIndicesNames.add(indexName);
            }
        }
        if (systemIndicesNames.isEmpty() == false) {
            deprecationLogger.deprecate("open_system_index_access",
                "this request accesses system indices: {}, but in a future major version, direct access to system " +
                    "indices will be prevented by default", systemIndicesNames);
        } else {
            checkSystemAliasAccess(request, systemIndices);
        }
    }

    private static void checkSystemAliasAccess(GetAliasesRequest request, SystemIndices systemIndices) {
        final List systemAliases = Arrays.stream(request.aliases())
            .filter(alias -> systemIndices.isSystemIndex(alias))
            .collect(Collectors.toList());
        if (systemAliases.isEmpty() == false) {
            deprecationLogger.deprecate("open_system_alias_access",
                "this request accesses aliases with names reserved for system indices: {}, but in a future major version, direct" +
                    "access to system indices and their aliases will not be allowed", systemAliases);
        }
    }
}