SQL: add support for index aliases for SYS COLUMNS command

x-pack/plugin/ql/src/main/java/org/elasticsearch/xpack/ql/index/IndexResolver.java

@@ -6,6 +6,7 @@
 package org.elasticsearch.xpack.ql.index;
 
 import com.carrotsearch.hppc.cursors.ObjectCursor;
+import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
 
 import org.elasticsearch.ElasticsearchSecurityException;
 import org.elasticsearch.action.ActionListener;
@@ -22,6 +23,7 @@
 import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.metadata.AliasMetaData;
 import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.xpack.ql.QlIllegalArgumentException;
@@ -41,9 +43,11 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.EnumSet;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -162,7 +166,6 @@ public boolean equals(Object obj) {
     private final String clusterName;
     private final DataTypeRegistry typeRegistry;
 
-
     public IndexResolver(Client client, String clusterName, DataTypeRegistry typeRegistry) {
         this.client = client;
         this.clusterName = clusterName;
@@ -294,7 +297,7 @@ public static IndexResolution mergedMappings(DataTypeRegistry typeRegistry, Stri
         }
 
         // merge all indices onto the same one
-        List<EsIndex> indices = buildIndices(typeRegistry, indexNames, null, fieldCaps, i -> indexPattern, (n, types) -> {
+        List<EsIndex> indices = buildIndices(typeRegistry, indexNames, null, fieldCaps, null, i -> indexPattern, (n, types) -> {
             StringBuilder errorMessage = new StringBuilder();
 
             boolean hasUnmapped = types.containsKey(UNMAPPED);
@@ -460,15 +463,31 @@ public void resolveAsSeparateMappings(String indexWildcard, String javaRegex, bo
         FieldCapabilitiesRequest fieldRequest = createFieldCapsRequest(indexWildcard, includeFrozen);
         client.fieldCaps(fieldRequest,
                 ActionListener.wrap(
-                        response -> listener.onResponse(
-                                separateMappings(typeRegistry, indexWildcard, javaRegex, response.getIndices(), response.get())),
+                        response -> {
+                            String[] indicesList = response.getIndices();
+                            GetAliasesRequest aliasRequest = new GetAliasesRequest()
+                                    .local(true)
+                                    .aliases("*")
+                                    .indices(indicesList)
+                                    .indicesOptions(IndicesOptions.lenientExpandOpen());
+                            client.admin().indices().getAliases(aliasRequest, wrap(aliases ->
+                                listener.onResponse(separateMappings(typeRegistry, javaRegex, indicesList, response.get(),
+                                        aliases.getAliases())),
+                                ex -> {
+                                    if (ex instanceof IndexNotFoundException || ex instanceof ElasticsearchSecurityException) {
+                                        listener.onResponse(separateMappings(typeRegistry, javaRegex, indicesList, response.get(), null));
+                                    } else {
+                                        listener.onFailure(ex);
+                                    }
+                                }));
+                        },
                         listener::onFailure));
 
     }
 
-    public static List<EsIndex> separateMappings(DataTypeRegistry typeRegistry, String indexPattern, String javaRegex, String[] indexNames,
-            Map<String, Map<String, FieldCapabilities>> fieldCaps) {
-        return buildIndices(typeRegistry, indexNames, javaRegex, fieldCaps, Function.identity(), (s, cap) -> null);
+    public static List<EsIndex> separateMappings(DataTypeRegistry typeRegistry, String javaRegex, String[] indexNames,
+            Map<String, Map<String, FieldCapabilities>> fieldCaps, ImmutableOpenMap<String, List<AliasMetaData>> aliases) {
+        return buildIndices(typeRegistry, indexNames, javaRegex, fieldCaps, aliases, Function.identity(), (s, cap) -> null);
     }
 
     private static class Fields {
@@ -481,16 +500,26 @@ private static class Fields {
      * each field.
      */
     private static List<EsIndex> buildIndices(DataTypeRegistry typeRegistry, String[] indexNames, String javaRegex,
-            Map<String, Map<String, FieldCapabilities>> fieldCaps,
+            Map<String, Map<String, FieldCapabilities>> fieldCaps, ImmutableOpenMap<String, List<AliasMetaData>> aliases,
             Function<String, String> indexNameProcessor,
             BiFunction<String, Map<String, FieldCapabilities>, InvalidMappedField> validityVerifier) {
 
-        if (indexNames == null || indexNames.length == 0) {
+        if ((indexNames == null || indexNames.length == 0) && (aliases == null || aliases.size() == 0)) {
             return emptyList();
         }
 
-        final List<String> resolvedIndices = asList(indexNames);
-        Map<String, Fields> indices = new LinkedHashMap<>(resolvedIndices.size());
+        Set<String> resolvedAliases = new LinkedHashSet<>();
+        if (aliases != null) {
+            Iterator<ObjectObjectCursor<String, List<AliasMetaData>>> iterator = aliases.iterator();
+            while (iterator.hasNext()) {
+                for(AliasMetaData alias : iterator.next().value) {
+                    resolvedAliases.add(alias.getAlias());
+                }
+            }
+        }
+
+        List<String> resolvedIndices = new ArrayList<>(asList(indexNames));
+        Map<String, Fields> indices = new LinkedHashMap<>(resolvedIndices.size() + resolvedAliases.size());
         Pattern pattern = javaRegex != null ? Pattern.compile(javaRegex) : null;
 
         // sort fields in reverse order to build the field hierarchy
@@ -508,8 +537,10 @@ private static List<EsIndex> buildIndices(DataTypeRegistry typeRegistry, String[
                 continue;
             }
 
-            // apply verification
+            // apply verification for individual fields
             final InvalidMappedField invalidField = validityVerifier.apply(fieldName, types);
+            // apply verification for fields belonging to index aliases
+            Map<String, InvalidMappedField> invalidFieldsForAliases = getInvalidFieldsForAliases(fieldName, types, aliases);
 
             // filter meta fields and unmapped
             FieldCapabilities unmapped = types.get(UNMAPPED);
@@ -530,7 +561,7 @@ private static List<EsIndex> buildIndices(DataTypeRegistry typeRegistry, String[
                 List<String> concreteIndices = null;
                 if (capIndices != null) {
                     if (unmappedIndices.isEmpty()) {
-                        concreteIndices = asList(capIndices);
+                        concreteIndices = new ArrayList<>(asList(capIndices));
                     } else {
                         concreteIndices = new ArrayList<>(capIndices.length);
                         for (String capIndex : capIndices) {
@@ -544,38 +575,63 @@ private static List<EsIndex> buildIndices(DataTypeRegistry typeRegistry, String[
                     concreteIndices = resolvedIndices;
                 }
 
+                // add to the list of concrete indices the aliases associated with these indices
+                Set<String> uniqueAliases = new LinkedHashSet<>();
+                if (aliases != null) {
+                    for (String concreteIndex : concreteIndices) {
+                        if (aliases.containsKey(concreteIndex)) {
+                            List<AliasMetaData> concreteIndexAliases = aliases.get(concreteIndex);
+                            concreteIndexAliases.stream().forEach(e -> uniqueAliases.add(e.alias()));
+                        }
+                    }
+                    concreteIndices.addAll(uniqueAliases);
+                }
+
                 // put the field in their respective mappings
                 for (String index : concreteIndices) {
-                    if (pattern == null || pattern.matcher(index).matches()) {
-                        String indexName = indexNameProcessor.apply(index);
+                    boolean isIndexAlias = uniqueAliases.contains(index);
+                    if (pattern == null || pattern.matcher(index).matches() || isIndexAlias) {
+                        String indexName = isIndexAlias ? index : indexNameProcessor.apply(index);
                         Fields indexFields = indices.get(indexName);
                         if (indexFields == null) {
                             indexFields = new Fields();
                             indices.put(indexName, indexFields);
                         }
                         EsField field = indexFields.flattedMapping.get(fieldName);
-                        if (field == null || (invalidField != null && (field instanceof InvalidMappedField) == false)) {
+                        boolean createField = false;
+                        if (isIndexAlias == false) {
+                            if (field == null || (invalidField != null && (field instanceof InvalidMappedField) == false)) {
+                                createField = true;
+                            }
+                        }
+                        else {
+                            if (field == null && invalidFieldsForAliases.get(index) == null) {
+                                createField = true;
+                            }
+                        }
+
+                        if (createField) {
                             int dot = fieldName.lastIndexOf('.');
                             /*
                              * Looking up the "tree" at the parent fields here to see if the field is an alias.
                              * When the upper elements of the "tree" have no elements in fieldcaps, then this is an alias field. But not
                              * always: if there are two aliases - a.b.c.alias1 and a.b.c.alias2 - only one of them will be considered alias.
                              */
-                            Holder<Boolean> isAlias = new Holder<>(false);
+                            Holder<Boolean> isAliasFieldType = new Holder<>(false);
                             if (dot >= 0) {
                                 String parentName = fieldName.substring(0, dot);
                                 if (indexFields.flattedMapping.get(parentName) == null) {
                                     // lack of parent implies the field is an alias
                                     if (fieldCaps.get(parentName) == null) {
-                                        isAlias.set(true);
+                                        isAliasFieldType.set(true);
                                     }
                                 }
                             }
 
                             createField(typeRegistry, fieldName, fieldCaps, indexFields.hierarchicalMapping, indexFields.flattedMapping,
                                     s -> invalidField != null ? invalidField :
                                         createField(typeRegistry, s, typeCap.getType(), emptyMap(), typeCap.isAggregatable(),
-                                                isAlias.get()));
+                                                isAliasFieldType.get()));
                         }
                     }
                 }
@@ -590,4 +646,134 @@ private static List<EsIndex> buildIndices(DataTypeRegistry typeRegistry, String[
         foundIndices.sort(Comparator.comparing(EsIndex::name));
         return foundIndices;
     }
+
+
+    /*
+     * Checks if the field is valid (same type and same capabilities - searchable/aggregatable) across indices belonging to a list
+     * of aliases.
+     * A field can look like the example below (generated by field_caps API).
+     *   "name": {
+     *       "text": {
+     *           "type": "text",
+     *           "searchable": false,
+     *           "aggregatable": false,
+     *           "indices": [
+     *               "bar",
+     *               "foo"
+     *           ],
+     *           "non_searchable_indices": [
+     *               "foo"
+     *           ]
+     *       },
+     *       "keyword": {
+     *           "type": "keyword",
+     *           "searchable": false,
+     *           "aggregatable": true,
+     *           "non_aggregatable_indices": [
+     *               "bar", "baz"
+     *           ]
+     *       }
+     *   }
+     */
+    private static Map<String, InvalidMappedField> getInvalidFieldsForAliases(String fieldName, Map<String, FieldCapabilities> types,
+            ImmutableOpenMap<String, List<AliasMetaData>> aliases) {
+        if (aliases == null || aliases.isEmpty()) {
+            return emptyMap();
+        }
+        Map<String, InvalidMappedField> invalidFields = new HashMap<>();
+        Map<String, Set<String>> typesErrors = new HashMap<>();
+        Map<String, Set<String>> aliasToIndices = new HashMap<>(); // map with aliases and their list of indices
+
+        Iterator<ObjectObjectCursor<String, List<AliasMetaData>>> iter = aliases.iterator();
+        while (iter.hasNext()) {
+            ObjectObjectCursor<String, List<AliasMetaData>> index = iter.next();
+            for (AliasMetaData aliasMetaData : index.value) {
+                String aliasName = aliasMetaData.alias();
+                typesErrors.putIfAbsent(aliasName, new HashSet<>());
+                aliasToIndices.putIfAbsent(aliasName, new HashSet<String>());
+                aliasToIndices.get(aliasName).add(index.key);
+            }
+        }
+
+        // iterate over each type
+        for (Entry<String, FieldCapabilities> type : types.entrySet()) {
+            if (type.getKey() == UNMAPPED) {
+                continue;
+            }
+            String[] indices = type.getValue().indices();
+            // if there is a list of indices where this field type is defined
+            if (indices != null) {
+                // Look at all these indices' aliases and add the type of the field to a list (Set) with unique elements.
+                // A valid mapping for a field in an index alias should contain only one type. If it doesn't this means that field
+                // is mapped as different types across the indices in this index alias.
+                for (String index : indices) {
+                    List<AliasMetaData> indexAliases = aliases.get(index);
+                    if (indexAliases == null) {
+                        continue;
+                    }
+                    for (AliasMetaData aliasMetaData : indexAliases) {
+                        typesErrors.get(aliasMetaData.alias()).add(type.getKey());
+                    }
+                }
+            }
+        }
+
+        for (Entry<String, Set<String>> entry : typesErrors.entrySet()) {
+            String aliasName = entry.getKey();
+            // if, for the same index alias, there are multiple field types for this fieldName ie the index alias has indices where the same
+            // field name is of different types
+            if (entry.getValue().size() > 1) {
+                // consider the field as invalid, for the currently checked index alias
+                // the error message doesn't actually matter
+                invalidFields.put(aliasName, new InvalidMappedField(fieldName));
+            } else {
+                // if the field type is the same across all this alias' indices, check the field's capabilities (searchable/aggregatable)
+                for (Entry<String, FieldCapabilities> type : types.entrySet()) {
+                    if (type.getKey() == UNMAPPED) {
+                        continue;
+                    }
+                    FieldCapabilities f = type.getValue();
+
+                    // the existence of a list of non_aggregatable_indices is an indication that not all indices have the same capabilities
+                    // but this list can contain indices belonging to other aliases, so we need to check only for this alias
+                    if (f.nonAggregatableIndices() != null) {
+                        Set<String> aliasIndices = aliasToIndices.get(aliasName);
+                        int nonAggregatableCount = 0;
+                        // either all or none of the non-aggregatable indices belonging to a certain alias should be in this list
+                        for (String nonAggIndex : f.nonAggregatableIndices()) {
+                            if (aliasIndices.contains(nonAggIndex)) {
+                                nonAggregatableCount++;
+                            }
+                        }
+                        if (nonAggregatableCount > 0 && nonAggregatableCount != aliasIndices.size()) {
+                            invalidFields.put(aliasName, new InvalidMappedField(fieldName));
+                            break;
+                        }
+                    }
+
+                    // perform the same check for non_searchable_indices list
+                    if (f.nonSearchableIndices() != null) {
+                        Set<String> aliasIndices = aliasToIndices.get(aliasName);
+                        int nonSearchableCount = 0;
+                        // either all or none of the non-searchable indices belonging to a certain alias should be in this list
+                        for (String nonSearchIndex : f.nonSearchableIndices()) {
+                            if (aliasIndices.contains(nonSearchIndex)) {
+                                nonSearchableCount++;
+                            }
+                        }
+                        if (nonSearchableCount > 0 && nonSearchableCount != aliasIndices.size()) {
+                            invalidFields.put(aliasName, new InvalidMappedField(fieldName));
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+
+        if (invalidFields.size() > 0) {
+            return invalidFields;
+        }
+        // everything checks
+        return emptyMap();
+    }
 }

x-pack/plugin/ql/src/main/java/org/elasticsearch/xpack/ql/type/InvalidMappedField.java

@@ -25,6 +25,11 @@ public InvalidMappedField(String name, String errorMessage) {
         this.errorMessage = errorMessage;
     }
 
+    public InvalidMappedField(String name) {
+        super(name, DataTypes.UNSUPPORTED, emptyMap(), false);
+        this.errorMessage = StringUtils.EMPTY;
+    }
+
     public String errorMessage() {
         return errorMessage;
     }

x-pack/plugin/sql/qa/single-node/src/test/java/org/elasticsearch/xpack/sql/qa/single_node/SysColumnsIT.java

@@ -0,0 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+package org.elasticsearch.xpack.sql.qa.single_node;
+
+import org.elasticsearch.xpack.sql.qa.jdbc.SysColumnsTestCase;
+
+public class SysColumnsIT extends SysColumnsTestCase {
+
+}