Remove (deprecated) support for '+' in index expressions (#25274)

Relates to #24515

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

@@ -29,8 +29,6 @@ import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.joda.DateMathParser;
 import org.elasticsearch.common.joda.FormatDateTimeFormatter;
-import org.elasticsearch.common.logging.DeprecationLogger;
-import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.Index;
@@ -58,8 +56,6 @@ public class IndexNameExpressionResolver extends AbstractComponent {
 
     private final List<ExpressionResolver> expressionResolvers;
     private final DateMathExpressionResolver dateMathExpressionResolver;
-    private static final DeprecationLogger DEPRECATION_LOGGER =
-        new DeprecationLogger(Loggers.getLogger(IndexNameExpressionResolver.class));
 
     public IndexNameExpressionResolver(Settings settings) {
         super(settings);
@@ -592,7 +588,6 @@ public class IndexNameExpressionResolver extends AbstractComponent {
         private Set<String> innerResolve(Context context, List<String> expressions, IndicesOptions options, MetaData metaData) {
             Set<String> result = null;
             boolean wildcardSeen = false;
-            boolean plusSeen = false;
             for (int i = 0; i < expressions.size(); i++) {
                 String expression = expressions.get(i);
                 if (aliasOrIndexExists(metaData, expression)) {
@@ -605,14 +600,7 @@ public class IndexNameExpressionResolver extends AbstractComponent {
                     throw infe(expression);
                 }
                 boolean add = true;
-                if (expression.charAt(0) == '+') {
-                    // if its the first, add empty result set
-                    plusSeen = true;
-                    if (i == 0) {
-                        result = new HashSet<>();
-                    }
-                    expression = expression.substring(1);
-                } else if (expression.charAt(0) == '-') {
+                if (expression.charAt(0) == '-') {
                     // if there is a negation without a wildcard being previously seen, add it verbatim,
                     // otherwise return the expression
                     if (wildcardSeen) {
@@ -655,9 +643,6 @@ public class IndexNameExpressionResolver extends AbstractComponent {
                     wildcardSeen = true;
                 }
             }
-            if (plusSeen) {
-              DEPRECATION_LOGGER.deprecated("support for '+' as part of index expressions is deprecated");
-            }
             return result;
         }
 

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

@@ -1027,24 +1027,6 @@ public class IndexNameExpressionResolverTests extends ESTestCase {
         assertArrayEquals(new String[] {"test-alias-0", "test-alias-1", "test-alias-non-filtering"}, strings);
     }
 
-    public void testConcreteIndicesForDeprecatedPattern() {
-        MetaData.Builder mdBuilder = MetaData.builder()
-            .put(indexBuilder("testXXX").state(State.OPEN))
-            .put(indexBuilder("testXXY").state(State.OPEN))
-            .put(indexBuilder("testYYY").state(State.OPEN));
-        ClusterState state = ClusterState.builder(new ClusterName("_name")).metaData(mdBuilder).build();
-
-        IndexNameExpressionResolver.Context context = new IndexNameExpressionResolver.Context(state,
-            IndicesOptions.fromOptions(true, true, true, true));
-        assertThat(newHashSet(indexNameExpressionResolver.concreteIndexNames(context, "+testX*")),
-            equalTo(newHashSet("testXXX", "testXXY")));
-        assertThat(newHashSet(indexNameExpressionResolver.concreteIndexNames(context, "+testXXX", "+testXXY", "+testYYY", "-testYYY")),
-            equalTo(newHashSet("testXXX", "testXXY", "testYYY")));
-        assertThat(newHashSet(indexNameExpressionResolver.concreteIndexNames(context, "+testXX*", "+testY*")),
-            equalTo(newHashSet("testXXX", "testXXY", "testYYY")));
-        assertWarnings("support for '+' as part of index expressions is deprecated");
-    }
-
     public void testDeleteIndexIgnoresAliases() {
         MetaData.Builder mdBuilder = MetaData.builder()
                 .put(indexBuilder("test-index").state(State.OPEN)

core/src/test/java/org/elasticsearch/cluster/metadata/WildcardExpressionResolverTests.java

@@ -182,20 +182,4 @@ public class WildcardExpressionResolverTests extends ESTestCase {
     private IndexMetaData.Builder indexBuilder(String index) {
         return IndexMetaData.builder(index).settings(settings(Version.CURRENT).put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1).put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 0));
     }
-
-    public void testForDeprecatedPlusPattern() {
-        MetaData.Builder mdBuilder = MetaData.builder()
-            .put(indexBuilder("testXXX").state(IndexMetaData.State.OPEN))
-            .put(indexBuilder("testXYY").state(IndexMetaData.State.OPEN))
-            .put(indexBuilder("testYYY").state(IndexMetaData.State.OPEN));
-        ClusterState state = ClusterState.builder(new ClusterName("_name")).metaData(mdBuilder).build();
-        IndexNameExpressionResolver.WildcardExpressionResolver resolver = new IndexNameExpressionResolver.WildcardExpressionResolver();
-
-        IndexNameExpressionResolver.Context context = new IndexNameExpressionResolver.Context(state, IndicesOptions.fromOptions(true, true, true, true));
-        assertThat(newHashSet(resolver.resolve(context, Arrays.asList("+testX*", "-testYYY"))), equalTo(newHashSet("testXXX", "testXYY")));
-        assertThat(newHashSet(resolver.resolve(context, Arrays.asList("+testYYY", "+testXY*"))), equalTo(newHashSet("testYYY", "testXYY")));
-        assertThat(newHashSet(resolver.resolve(context, Arrays.asList("testYYY", "+testXX*"))), equalTo(newHashSet("testXXX", "testYYY")));
-        assertWarnings("support for '+' as part of index expressions is deprecated");
-    }
-
 }

docs/reference/api-conventions.asciidoc

@@ -20,8 +20,8 @@ API, unless otherwise specified.
 
 Most APIs that refer to an `index` parameter support execution across multiple indices,
 using simple `test1,test2,test3` notation (or `_all` for all indices). It also
-support wildcards, for example: `test*` or `*test` or `te*t` or `*test*`, and the ability to "add" (`+`)
-and "remove" (`-`), for example: `+test*,-test3`.
+support wildcards, for example: `test*` or `*test` or `te*t` or `*test*`, and the
+ability to "exclude" (`-`), for example: `test*,-test3`.
 
 All multi indices API support the following url query string parameters:
 

docs/reference/migration/migrate_6_0/indices.asciidoc

@@ -62,3 +62,9 @@ which will expand to matching indices).
 The index parameter in the delete index API no longer accepts alias names.
 Instead, it accepts only index names (or wildcards which will expand to
 matching indices).
+
+==== Support for '+' has been removed in index expressions
+
+Omitting the '+' has the same effect as specifying it, hence support for '+'
+has been removed in index expressions.
+