Add tier_preference and node.role columns to _cat/shards API

docs/changelog/138405.yaml

@@ -0,0 +1,6 @@
+pr: 138405
+summary: Add tier_preference and node.role columns to _cat/shards API
+area: CAT APIs
+type: enhancement
+issues:
+ - 136895

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/cat.shards/10_basic.yml

@@ -88,6 +88,8 @@
              bulk.avg_size_in_bytes           .+   \n
              dense_vector.value_count         .+   \n
              sparse_vector.value_count        .+   \n
+             tier_preference                  .+   \n
+             node.role                        .+   \n
         $/
 ---
 "Test cat shards output":
@@ -115,7 +117,7 @@
 
   - match:
       $body: |
-        /^(index1 \s+ \d \s+ (p|r) \s+ ((STARTED|INITIALIZING|RELOCATING) \s+ (\d \s+ (\d+|\d+[.]\d+)(kb|b) \s+ (\d+|\d+[.]\d+)(kb|b) \s+)? \d{1,3}.\d{1,3}.\d{1,3}.\d{1,3} \s+ .+|UNASSIGNED \s+)  \n?){10}$/
+        /^(index1 \s+ \d \s+ (p|r) \s+ ((STARTED|INITIALIZING|RELOCATING) \s+ (\d \s+ (\d+|\d+[.]\d+)(kb|b) \s+ (\d+|\d+[.]\d+)(kb|b) \s+)? \d{1,3}.\d{1,3}.\d{1,3}.\d{1,3} \s+ .+|UNASSIGNED \s+ \s+ \S* \s+ \S*)  \n?){10}$/
 
   - do:
       indices.create:
@@ -130,14 +132,14 @@
         index: i*
   - match:
       $body: |
-        /^(index(1|2) \s+ \d \s+ (p|r) \s+ ((STARTED|INITIALIZING|RELOCATING) \s+ (\d \s+ (\d+|\d+[.]\d+)(kb|b) \s+ (\d+|\d+[.]\d+)(kb|b) \s+)? \d{1,3}.\d{1,3}.\d{1,3}.\d{1,3} \s+ .+|UNASSIGNED \s+) \n?){15}$/
+        /^(index(1|2) \s+ \d \s+ (p|r) \s+ ((STARTED|INITIALIZING|RELOCATING) \s+ (\d \s+ (\d+|\d+[.]\d+)(kb|b) \s+ (\d+|\d+[.]\d+)(kb|b) \s+)? \d{1,3}.\d{1,3}.\d{1,3}.\d{1,3} \s+ .+|UNASSIGNED \s+ \s+ \S* \s+ \S*) \n?){15}$/
 
   - do:
       cat.shards:
         index: index2
   - match:
       $body: |
-        /^(index2 \s+ \d \s+ (p|r) \s+ ((STARTED|INITIALIZING|RELOCATING) \s+ (\d \s+ (\d+|\d+[.]\d+)(kb|b) \s+ (\d+|\d+[.]\d+)(kb|b) \s+)? \d{1,3}.\d{1,3}.\d{1,3}.\d{1,3} \s+ .+|UNASSIGNED \s+) \n?){5}$/
+        /^(index2 \s+ \d \s+ (p|r) \s+ ((STARTED|INITIALIZING|RELOCATING) \s+ (\d \s+ (\d+|\d+[.]\d+)(kb|b) \s+ (\d+|\d+[.]\d+)(kb|b) \s+)? \d{1,3}.\d{1,3}.\d{1,3}.\d{1,3} \s+ .+|UNASSIGNED \s+ \s+ \S* \s+ \S*) \n?){5}$/
 
 ---
 "Test cat shards using wildcards":

server/src/main/java/org/elasticsearch/rest/action/cat/RestShardsAction.java

@@ -17,6 +17,8 @@
 import org.elasticsearch.action.admin.indices.stats.ShardStats;
 import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.client.internal.node.NodeClient;
+import org.elasticsearch.cluster.metadata.IndexMetadata;
+import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.cluster.routing.UnassignedInfo;
 import org.elasticsearch.common.Strings;
@@ -51,6 +53,7 @@
 import java.time.Instant;
 import java.util.List;
 import java.util.Locale;
+import java.util.Optional;
 import java.util.function.Function;
 
 import static org.elasticsearch.rest.RestRequest.Method.GET;
@@ -261,7 +264,11 @@ protected Table getTableWithHeader(final RestRequest request) {
             "sparse_vector.value_count",
             "alias:svc,sparseVectorCount;default:false;text-align:right;desc:number of indexed sparse vectors in shard"
         );
-
+        table.addCell("tier_preference", "alias:tp;desc:preference for the tier of the index");
+        table.addCell(
+            "node.role",
+            "alias:r,role,nodeRole;desc:m:master eligible node, d:data node, i:ingest node, -:coordinating node only"
+        );
         table.endHeaders();
         return table;
     }
@@ -431,6 +438,21 @@ Table buildTable(RestRequest request, ClusterStateResponse state, IndicesStatsRe
             table.addCell(getOrNull(commonStats, CommonStats::getDenseVectorStats, DenseVectorStats::getValueCount));
             table.addCell(getOrNull(commonStats, CommonStats::getSparseVectorStats, SparseVectorStats::getValueCount));
 
+            table.addCell(
+                Optional.ofNullable(
+                    getOrNull(
+                        state.getState().metadata().findIndex(shard.index()).orElse(null),
+                        IndexMetadata::getSettings,
+                        s -> s.get("index.routing.allocation.include._tier_preference")
+                    )
+                ).orElse("")
+            );
+            table.addCell(
+                Optional.ofNullable(shard.currentNodeId())
+                    .map(id -> state.getState().nodes().get(id))
+                    .map(DiscoveryNode::getRoleAbbreviationString)
+                    .orElse("-")
+            );
             table.endRow();
         }
 

server/src/test/java/org/elasticsearch/rest/action/cat/RestShardsActionTests.java

@@ -9,12 +9,15 @@
 
 package org.elasticsearch.rest.action.cat;
 
+import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.cluster.state.ClusterStateResponse;
 import org.elasticsearch.action.admin.indices.stats.CommonStats;
 import org.elasticsearch.action.admin.indices.stats.CommonStatsFlags;
 import org.elasticsearch.action.admin.indices.stats.IndicesStatsResponse;
 import org.elasticsearch.action.admin.indices.stats.ShardStats;
 import org.elasticsearch.cluster.ClusterState;
+import org.elasticsearch.cluster.metadata.IndexMetadata;
+import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.node.DiscoveryNodeUtils;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
@@ -23,6 +26,7 @@
 import org.elasticsearch.cluster.routing.ShardRoutingState;
 import org.elasticsearch.cluster.routing.TestShardRouting;
 import org.elasticsearch.common.Table;
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.shard.IndexingStats;
 import org.elasticsearch.index.shard.ShardPath;
 import org.elasticsearch.test.ESTestCase;
@@ -34,8 +38,11 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertNotNull;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -128,6 +135,13 @@ private void mockShardStats(boolean includeCommonStats) {
         this.shardRoutings = new ArrayList<>(numShards);
         Map<ShardRouting, ShardStats> shardStatsMap = new HashMap<>();
         String index = "index";
+        Metadata metadata = mock(Metadata.class);
+        IndexMetadata indexMetadata = IndexMetadata.builder(index)
+            .settings(Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT))
+            .numberOfShards(1)
+            .numberOfReplicas(1)
+            .build();
+        when(metadata.findIndex(any())).thenReturn(Optional.of(indexMetadata));
         for (int i = 0; i < numShards; i++) {
             ShardRoutingState shardRoutingState = ShardRoutingState.fromValue((byte) randomIntBetween(2, 3));
             ShardRouting shardRouting = TestShardRouting.newShardRouting(index, i, localNode.getId(), randomBoolean(), shardRoutingState);
@@ -186,6 +200,37 @@ private void mockShardStats(boolean includeCommonStats) {
         ClusterState clusterState = mock(ClusterState.class);
         when(clusterState.routingTable()).thenReturn(routingTable);
         when(clusterState.nodes()).thenReturn(discoveryNodes);
+        when(clusterState.metadata()).thenReturn(metadata);
         when(clusterStateResponse.getState()).thenReturn(clusterState);
     }
+
+    public void testNewColumnsAndNullSafety() {
+        mockShardStats(false);
+
+        final RestShardsAction action = new RestShardsAction();
+        final Table table = action.buildTable(new FakeRestRequest(), clusterStateResponse, indicesStatsResponse);
+
+        List<Table.Cell> headers = table.getHeaders();
+
+        int tierPreferenceIndex = -1;
+        int nodeRoleIndex = -1;
+
+        for (int i = 0; i < headers.size(); i++) {
+            if ("tier_preference".equals(headers.get(i).value)) {
+                tierPreferenceIndex = i;
+            }
+            if ("node.role".equals(headers.get(i).value)) {
+                nodeRoleIndex = i;
+            }
+        }
+
+        final List<List<Table.Cell>> rows = table.getRows();
+        assertThat(rows.size(), equalTo(shardRoutings.size()));
+
+        for (final List<Table.Cell> row : rows) {
+            assertThat(row.get(tierPreferenceIndex).value, equalTo(""));
+            assertNotNull(row.get(nodeRoleIndex).value);
+        }
+    }
+
 }