Return error when remote indices are locally resolved

server/src/internalClusterTest/java/org/elasticsearch/get/GetActionIT.java

@@ -19,13 +19,13 @@
 import org.elasticsearch.action.get.MultiGetResponse;
 import org.elasticsearch.action.index.IndexResponse;
 import org.elasticsearch.action.support.DefaultShardOperationFailedException;
-import org.elasticsearch.core.Nullable;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.lucene.uid.Versions;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentType;
+import org.elasticsearch.core.Nullable;
 import org.elasticsearch.index.IndexModule;
 import org.elasticsearch.index.engine.EngineTestCase;
 import org.elasticsearch.index.engine.VersionConflictEngineException;
@@ -781,6 +781,12 @@ void indexSingleDocumentWithStringFieldsGeneratedFromText(boolean stored, boolea
         index("test", "1", doc);
     }
 
+    public void testGetRemoteIndex() {
+        IllegalArgumentException iae = expectThrows(IllegalArgumentException.class, () -> client().prepareGet("cluster:index", "id").get());
+        assertEquals("Cross-cluster calls are not supported in this context but remote indices were requested: [cluster:index]",
+            iae.getMessage());
+    }
+
     private void assertGetFieldsAlwaysWorks(String index, String docId, String[] fields) {
         assertGetFieldsAlwaysWorks(index, docId, fields, null);
     }

server/src/main/java/org/elasticsearch/cluster/metadata/IndexNameExpressionResolver.java

@@ -14,7 +14,6 @@
 import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexAbstraction.Type;
-import org.elasticsearch.core.Nullable;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.logging.DeprecationCategory;
@@ -26,6 +25,7 @@
 import org.elasticsearch.common.util.CollectionUtils;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
 import org.elasticsearch.common.util.set.Sets;
+import org.elasticsearch.core.Nullable;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexNotFoundException;
 import org.elasticsearch.indices.IndexClosedException;
@@ -112,7 +112,7 @@ public Index[] concreteIndices(ClusterState state, IndicesRequest request) {
      * provided indices options in the context don't allow such a case, or if the final result of the indices resolution
      * contains no indices and the indices options in the context don't allow such a case.
      * @throws IllegalArgumentException if one of the aliases resolve to multiple indices and the provided
-     * indices options in the context don't allow such a case.
+     * indices options in the context don't allow such a case; if a remote index is requested.
      */
     public String[] concreteIndexNames(ClusterState state, IndicesOptions options, String... indexExpressions) {
         Context context = new Context(state, options, getSystemIndexAccessPredicate());
@@ -163,7 +163,7 @@ public List<String> dataStreamNames(ClusterState state, IndicesOptions options,
      * provided indices options in the context don't allow such a case, or if the final result of the indices resolution
      * contains no indices and the indices options in the context don't allow such a case.
      * @throws IllegalArgumentException if one of the aliases resolve to multiple indices and the provided
-     * indices options in the context don't allow such a case.
+     * indices options in the context don't allow such a case; if a remote index is requested.
      */
     public Index[] concreteIndices(ClusterState state, IndicesOptions options, String... indexExpressions) {
         return concreteIndices(state, options, false, indexExpressions);
@@ -185,7 +185,7 @@ public Index[] concreteIndices(ClusterState state, IndicesOptions options, boole
      * provided indices options in the context don't allow such a case, or if the final result of the indices resolution
      * contains no indices and the indices options in the context don't allow such a case.
      * @throws IllegalArgumentException if one of the aliases resolve to multiple indices and the provided
-     * indices options in the context don't allow such a case.
+     * indices options in the context don't allow such a case; if a remote index is requested.
      */
     public Index[] concreteIndices(ClusterState state, IndicesRequest request, long startTime) {
         Context context = new Context(state, request.indicesOptions(), startTime, false, false, request.includeDataStreams(), false,
@@ -203,11 +203,20 @@ String[] concreteIndexNames(Context context, String... indexExpressions) {
     }
 
     Index[] concreteIndices(Context context, String... indexExpressions) {
+        Metadata metadata = context.getState().metadata();
+        IndicesOptions options = context.getOptions();
         if (indexExpressions == null || indexExpressions.length == 0) {
             indexExpressions = new String[]{Metadata.ALL};
+        } else {
+            if (options.ignoreUnavailable() == false) {
+                List<String> crossClusterIndices = Arrays.stream(indexExpressions)
+                    .filter(index -> index.contains(":")).collect(Collectors.toList());
+                if (crossClusterIndices.size() > 0) {
+                    throw new IllegalArgumentException("Cross-cluster calls are not supported in this context but remote indices " +
+                        "were requested: " + crossClusterIndices);
+                }
+            }
         }
-        Metadata metadata = context.getState().metadata();
-        IndicesOptions options = context.getOptions();
         // If only one index is specified then whether we fail a request if an index is missing depends on the allow_no_indices
         // option. At some point we should change this, because there shouldn't be a reason why whether a single index
         // or multiple indices are specified yield different behaviour.
@@ -386,7 +395,7 @@ private static IllegalArgumentException aliasesNotSupportedException(String expr
      * @param state             the cluster state containing all the data to resolve to expression to a concrete index
      * @param request           The request that defines how the an alias or an index need to be resolved to a concrete index
      *                          and the expression that can be resolved to an alias or an index name.
-     * @throws IllegalArgumentException if the index resolution lead to more than one index
+     * @throws IllegalArgumentException if the index resolution returns more than one index; if a remote index is requested.
      * @return the concrete index obtained as a result of the index resolution
      */
     public Index concreteSingleIndex(ClusterState state, IndicesRequest request) {
@@ -423,7 +432,8 @@ public Index concreteWriteIndex(ClusterState state, IndicesRequest request) {
      * @param index             index that can be resolved to alias or index name.
      * @param allowNoIndices    whether to allow resolve to no index
      * @param includeDataStreams Whether data streams should be included in the evaluation.
-     * @throws IllegalArgumentException if the index resolution does not lead to an index, or leads to more than one index
+     * @throws IllegalArgumentException if the index resolution does not lead to an index, or leads to more than one index, as well as
+     * if a remote index is requested.
      * @return the write index obtained as a result of the index resolution or null if no index
      */
     public Index concreteWriteIndex(ClusterState state, IndicesOptions options, String index, boolean allowNoIndices,

server/src/test/java/org/elasticsearch/cluster/metadata/IndexNameExpressionResolverTests.java

@@ -2394,6 +2394,27 @@ public void testMathExpressionSupportWithOlderDate() {
 
         assertEquals(resolved, "older-date-2020-12");
     }
+
+    public void testRemoteIndex() {
+        Metadata.Builder mdBuilder = Metadata.builder();
+        ClusterState state = ClusterState.builder(new ClusterName("_name")).metadata(mdBuilder).build();
+
+        {
+            IndicesOptions options = IndicesOptions.fromOptions(false, randomBoolean(), randomBoolean(), randomBoolean(), randomBoolean());
+            IndexNameExpressionResolver.Context context = new IndexNameExpressionResolver.Context(state, options, NONE);
+            IllegalArgumentException iae = expectThrows(IllegalArgumentException.class,
+                () -> indexNameExpressionResolver.concreteIndexNames(context, "cluster:index", "local"));
+            assertEquals("Cross-cluster calls are not supported in this context but remote indices were requested: [cluster:index]",
+                iae.getMessage());
+        }
+        {
+            IndicesOptions options = IndicesOptions.fromOptions(true, true, randomBoolean(), randomBoolean(), randomBoolean());
+            IndexNameExpressionResolver.Context context = new IndexNameExpressionResolver.Context(state, options, NONE);
+            String[] indexNames = indexNameExpressionResolver.concreteIndexNames(context, "cluster:index", "local");
+            assertEquals(0, indexNames.length);
+        }
+    }
+
     private ClusterState systemIndexTestClusterState() {
         Settings settings = Settings.builder().build();
         Metadata.Builder mdBuilder = Metadata.builder()