Deprecation check for http.enabled setting (#36394)

Adds a deprecation check for nodes with the deprecated setting
`http.enabled` set.

Author: gwbrown

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/DeprecationChecks.java

@@ -38,6 +38,7 @@ private DeprecationChecks() {
 
     static List<BiFunction<List<NodeInfo>, List<NodeStats>, DeprecationIssue>> NODE_SETTINGS_CHECKS =
         Collections.unmodifiableList(Arrays.asList(
+            NodeDeprecationChecks::httpEnabledSettingRemoved,
             NodeDeprecationChecks::tribeNodeCheck,
             NodeDeprecationChecks::azureRepositoryChanges,
             NodeDeprecationChecks::gcsRepositoryChanges,

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/NodeDeprecationChecks.java

@@ -8,6 +8,7 @@
 
 import org.elasticsearch.action.admin.cluster.node.info.NodeInfo;
 import org.elasticsearch.action.admin.cluster.node.stats.NodeStats;
+import org.elasticsearch.common.network.NetworkModule;
 import org.elasticsearch.xpack.core.deprecation.DeprecationIssue;
 
 import java.util.List;
@@ -18,6 +19,21 @@
  */
 public class NodeDeprecationChecks {
 
+    static DeprecationIssue httpEnabledSettingRemoved(List<NodeInfo> nodeInfos, List<NodeStats> nodeStats) {
+        List<String> nodesFound = nodeInfos.stream()
+            .filter(nodeInfo -> nodeInfo.getSettings().hasValue(NetworkModule.HTTP_ENABLED.getKey()))
+            .map(nodeInfo -> nodeInfo.getNode().getName())
+            .collect(Collectors.toList());
+        if (nodesFound.size() > 0) {
+            return new DeprecationIssue(DeprecationIssue.Level.CRITICAL,
+                "HTTP Enabled setting removed",
+                "https://www.elastic.co/guide/en/elasticsearch/reference/master/breaking_70_cluster_changes.html" +
+                    "#remove-http-enabled",
+                "nodes with http.enabled set: " + nodesFound);
+        }
+        return null;
+    }
+
     static DeprecationIssue tribeNodeCheck(List<NodeInfo> nodeInfos, List<NodeStats> nodeStats) {
         List<String> nodesFound = nodeInfos.stream()
             .filter(nodeInfo -> nodeInfo.getSettings().getByPrefix("tribe.").isEmpty() == false)

x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/NodeDeprecationChecksTests.java

@@ -59,6 +59,15 @@ null, null, null, null, new FsInfo(0L, null, paths), null, null, null,
         assertEquals(singletonList(expected), issues);
     }
 
+    public void testHttpEnabledCheck() {
+        DeprecationIssue expected = new DeprecationIssue(DeprecationIssue.Level.CRITICAL,
+            "HTTP Enabled setting removed",
+            "https://www.elastic.co/guide/en/elasticsearch/reference/master/breaking_70_cluster_changes.html" +
+                "#remove-http-enabled",
+            "nodes with http.enabled set: [node_check]");
+        assertSettingsAndIssue("http.enabled", Boolean.toString(randomBoolean()), expected);
+    }
+
     public void testTribeNodeCheck() {
         String tribeSetting = "tribe." + randomAlphaOfLengthBetween(1, 20) + ".cluster.name";
         DeprecationIssue expected = new DeprecationIssue(DeprecationIssue.Level.CRITICAL,