Add health status parameter to cat indices API

This commit adds a health status parameter to the cat indices API for
filtering on indices that match the specified status (green|yellow|red).

Relates #20393

core/src/main/java/org/elasticsearch/rest/action/cat/RestIndicesAction.java

@@ -27,9 +27,10 @@ import org.elasticsearch.action.admin.indices.stats.IndexStats;
 import org.elasticsearch.action.admin.indices.stats.IndicesStatsRequest;
 import org.elasticsearch.action.admin.indices.stats.IndicesStatsResponse;
 import org.elasticsearch.action.support.IndicesOptions;
-import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.client.Requests;
+import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.cluster.ClusterState;
+import org.elasticsearch.cluster.health.ClusterHealthStatus;
 import org.elasticsearch.cluster.health.ClusterIndexHealth;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
@@ -314,16 +315,32 @@ public class RestIndicesAction extends AbstractCatAction {
     }
 
     // package private for testing
-    Table buildTable(RestRequest request, Index[] indices, ClusterHealthResponse health, IndicesStatsResponse stats, MetaData indexMetaDatas) {
+    Table buildTable(RestRequest request, Index[] indices, ClusterHealthResponse response, IndicesStatsResponse stats, MetaData indexMetaDatas) {
+        final String healthParam = request.param("health");
+        final ClusterHealthStatus status;
+        if (healthParam != null) {
+            status = ClusterHealthStatus.fromString(healthParam);
+        } else {
+            status = null;
+        }
+
         Table table = getTableWithHeader(request);
 
         for (final Index index : indices) {
             final String indexName = index.getName();
-            ClusterIndexHealth indexHealth = health.getIndices().get(indexName);
+            ClusterIndexHealth indexHealth = response.getIndices().get(indexName);
             IndexStats indexStats = stats.getIndices().get(indexName);
             IndexMetaData indexMetaData = indexMetaDatas.getIndices().get(indexName);
             IndexMetaData.State state = indexMetaData.getState();
 
+            if (status != null) {
+                if (state == IndexMetaData.State.CLOSE ||
+                        (indexHealth == null && !ClusterHealthStatus.RED.equals(status)) ||
+                        !indexHealth.getStatus().equals(status)) {
+                    continue;
+                }
+            }
+
             table.startRow();
             table.addCell(state == IndexMetaData.State.OPEN ? (indexHealth == null ? "red*" : indexHealth.getStatus().toString().toLowerCase(Locale.ROOT)) : null);
             table.addCell(state.toString().toLowerCase(Locale.ROOT));

core/src/test/java/org/elasticsearch/rest/action/cat/RestIndicesActionTests.java

@@ -57,6 +57,7 @@ import org.elasticsearch.index.warmer.WarmerStats;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.search.suggest.completion.CompletionStats;
 import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.test.rest.FakeRestRequest;
 
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -107,7 +108,7 @@ public class RestIndicesActionTests extends ESTestCase {
             clusterState.getClusterName().value(), indicesStr, clusterState, 0, 0, 0, TimeValue.timeValueMillis(1000L)
         );
 
-        final Table table = action.buildTable(null, indices, clusterHealth, randomIndicesStatsResponse(indices), metaData);
+        final Table table = action.buildTable(new FakeRestRequest(), indices, clusterHealth, randomIndicesStatsResponse(indices), metaData);
 
         // now, verify the table is correct
         int count = 0;

docs/reference/cat/indices.asciidoc

@@ -33,7 +33,7 @@ Which indices are yellow?
 
 [source,sh]
 --------------------------------------------------
-% curl localhost:9200/_cat/indices | grep ^yell
+% curl localhost:9200/_cat/indices?health=yellow
 yellow open  wiki     2 1  6401 1115 151.4mb 151.4mb
 yellow open  twitter  5 1 11434    0    32mb    32mb
 --------------------------------------------------

rest-api-spec/src/main/resources/rest-api-spec/api/cat.indices.json

@@ -33,6 +33,10 @@
             "type": "list",
             "description" : "Comma-separated list of column names to display"
         },
+        "health": {
+            "type" : "string",
+            "description" : "A health status (\"green\", \"yellow\", or \"red\" to filter only indices matching the specified health status"
+        },
         "help": {
           "type": "boolean",
           "description": "Return help information",

rest-api-spec/src/main/resources/rest-api-spec/test/cat.indices/10_basic.yaml

@@ -70,6 +70,47 @@
                 )
                 $/
 
+---
+"Test cat indices using health status":
+
+  - do:
+      cluster.health: {}
+
+  - set: { number_of_data_nodes: count }
+
+  - do:
+      indices.create:
+        index: foo
+        body:
+          settings:
+            number_of_shards: "1"
+            number_of_replicas: "0"
+  - do:
+      indices.create:
+        index: bar
+        body:
+          settings:
+            number_of_shards: "1"
+            number_of_replicas: $count
+
+  - do:
+      cat.indices:
+        health: green
+        h: index
+
+  - match:
+      $body: |
+                /^(foo)$/
+
+  - do:
+      cat.indices:
+        health: yellow
+        h: index
+
+  - match:
+      $body: |
+               /^(bar)$/
+
 ---
 "Test cat indices using wildcards":