Convert ILM and SLM histories into hidden indices (elastic#51456)

Modifies SLM's and ILM's history indices to be hidden indices for added
protection against accidental querying and deletion, and improves
IndexTemplateRegistry to handle upgrading index templates.

Also modifies the REST test cleanup to delete hidden indices.

Author: gwbrown

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

@@ -120,7 +120,6 @@ public class MetaDataCreateIndexService {
      * These index patterns will be converted to hidden indices, at which point they should be removed from this list.
      */
     private static final CharacterRunAutomaton DOT_INDICES_EXCLUSIONS = new CharacterRunAutomaton(Regex.simpleMatchToAutomaton(
-        ".slm-history-*",
         ".watch-history-*",
         ".ml-anomalies-*",
         ".ml-notifications-*",

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

@@ -641,7 +641,6 @@ public void testValidateDotIndex() {
     public void testIndexNameExclusionsList() {
         // this test case should be removed when DOT_INDICES_EXCLUSIONS is empty
         List<String> excludedNames = Arrays.asList(
-            ".slm-history-" + randomAlphaOfLength(5).toLowerCase(Locale.ROOT),
             ".watch-history-" + randomAlphaOfLength(5).toLowerCase(Locale.ROOT),
             ".ml-anomalies-" + randomAlphaOfLength(5).toLowerCase(Locale.ROOT),
             ".ml-notifications-" + randomAlphaOfLength(5).toLowerCase(Locale.ROOT),

test/framework/src/main/java/org/elasticsearch/test/rest/ESRestTestCase.java

@@ -599,8 +599,11 @@ private void wipeCluster() throws Exception {
     }
 
     protected static void wipeAllIndices() throws IOException {
+        boolean includeHidden = minimumNodeVersion().onOrAfter(Version.V_7_7_0);
         try {
-            final Response response = adminClient().performRequest(new Request("DELETE", "*"));
+            final Request deleteReq = new Request("DELETE", "*");
+            deleteReq.addParameter("expand_wildcards", "open,closed" + (includeHidden ? ",hidden" : ""));
+            final Response response = adminClient().performRequest(deleteReq);
             try (InputStream is = response.getEntity().getContent()) {
                 assertTrue((boolean) XContentHelper.convertToMap(XContentType.JSON.xContent(), is, true).get("acknowledged"));
             }
@@ -1235,7 +1238,7 @@ protected static Version minimumNodeVersion() throws IOException {
         final Request request = new Request("GET", "_nodes");
         request.addParameter("filter_path", "nodes.*.version");
 
-        final Response response = client().performRequest(request);
+        final Response response = adminClient().performRequest(request);
         final Map<String, Object> nodes = ObjectPath.createFromResponse(response).evaluate("nodes");
 
         Version minVersion = null;

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/slm/history/SnapshotLifecycleTemplateRegistry.java

@@ -35,7 +35,8 @@
 public class SnapshotLifecycleTemplateRegistry extends IndexTemplateRegistry {
     // history (please add a comment why you increased the version here)
     // version 1: initial
-    public static final String INDEX_TEMPLATE_VERSION = "1";
+    // version 2: converted to hidden index
+    public static final int INDEX_TEMPLATE_VERSION = 2;
 
     public static final String SLM_TEMPLATE_VERSION_VARIABLE = "xpack.slm.template.version";
     public static final String SLM_TEMPLATE_NAME = ".slm-history";

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/template/IndexTemplateConfig.java

@@ -16,7 +16,7 @@ public class IndexTemplateConfig {
 
     private final String templateName;
     private final String fileName;
-    private final String version;
+    private final int version;
     private final String versionProperty;
 
     /**
@@ -27,14 +27,17 @@ public class IndexTemplateConfig {
      * {@code {"myTemplateVersion": "${my.version.property}"}}
      * With {@code version = "42"; versionProperty = "my.version.property"} will result in {@code {"myTemplateVersion": "42"}}.
      *
-     * @param templateName The name that will be used for the index template. Literal, include the version in this string if
+     * Note that this code does not automatically insert the {@code version} index template property - include that in the JSON file
+     * defining the template, preferably using the version variable provided to this constructor.
+     *
+     *  @param templateName The name that will be used for the index template. Literal, include the version in this string if
      *                     it should be used.
      * @param fileName The filename the template should be loaded from. Literal, should include leading {@literal /} and
      *                 extension if necessary.
      * @param version The version of the template. Substituted for {@code versionProperty} as described above.
      * @param versionProperty The property that will be replaced with the {@code version} string as described above.
      */
-    public IndexTemplateConfig(String templateName, String fileName, String version, String versionProperty) {
+    public IndexTemplateConfig(String templateName, String fileName, int version, String versionProperty) {
         this.templateName = templateName;
         this.fileName = fileName;
         this.version = version;
@@ -49,14 +52,20 @@ public String getTemplateName() {
         return templateName;
     }
 
+    public int getVersion() {
+        return version;
+    }
+
     /**
      * Loads the template from disk as a UTF-8 byte array.
      * @return The template as a UTF-8 byte array.
      */
     public byte[] loadBytes() {
-        String template = TemplateUtils.loadTemplate(fileName, version,
-            Pattern.quote("${" + versionProperty + "}"));
+        final String versionPattern = Pattern.quote("${" + versionProperty + "}");
+        String template = TemplateUtils.loadTemplate(fileName, Integer.toString(version), versionPattern);
         assert template != null && template.length() > 0;
+        assert Pattern.compile("\"version\"\\s*:\\s*" + version).matcher(template).find()
+            : "index template must have a version property set to the given version property";
         return template.getBytes(StandardCharsets.UTF_8);
     }
 }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/template/IndexTemplateRegistry.java

@@ -16,6 +16,7 @@
 import org.elasticsearch.cluster.ClusterChangedEvent;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.ClusterStateListener;
+import org.elasticsearch.cluster.metadata.IndexTemplateMetaData;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.settings.Settings;
@@ -31,6 +32,7 @@
 import org.elasticsearch.xpack.core.ilm.action.PutLifecycleAction;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
@@ -130,16 +132,24 @@ public void clusterChanged(ClusterChangedEvent event) {
 
     private void addTemplatesIfMissing(ClusterState state) {
         final List<IndexTemplateConfig> indexTemplates = getTemplateConfigs();
-        for (IndexTemplateConfig template : indexTemplates) {
-            final String templateName = template.getTemplateName();
+        for (IndexTemplateConfig newTemplate : indexTemplates) {
+            final String templateName = newTemplate.getTemplateName();
             final AtomicBoolean creationCheck = templateCreationsInProgress.computeIfAbsent(templateName, key -> new AtomicBoolean(false));
             if (creationCheck.compareAndSet(false, true)) {
-                if (!state.metaData().getTemplates().containsKey(templateName)) {
+                IndexTemplateMetaData currentTemplate = state.metaData().getTemplates().get(templateName);
+                if (Objects.isNull(currentTemplate)) {
                     logger.debug("adding index template [{}] for [{}], because it doesn't exist", templateName, getOrigin());
-                    putTemplate(template, creationCheck);
+                    putTemplate(newTemplate, creationCheck);
+                } else if (Objects.isNull(currentTemplate.getVersion()) || newTemplate.getVersion() > currentTemplate.getVersion()) {
+                    // IndexTemplateConfig now enforces templates contain a `version` property, so if the template doesn't have one we can
+                    // safely assume it's an old version of the template.
+                    logger.info("upgrading index template [{}] for [{}] from version [{}] to version [{}]",
+                        templateName, getOrigin(), currentTemplate.getVersion(), newTemplate.getVersion());
+                    putTemplate(newTemplate, creationCheck);
                 } else {
                     creationCheck.set(false);
-                    logger.trace("not adding index template [{}] for [{}], because it already exists", templateName, getOrigin());
+                    logger.trace("not adding index template [{}] for [{}], because it already exists at version [{}]",
+                        templateName, getOrigin(), currentTemplate.getVersion());
                 }
             } else {
                 logger.trace("skipping the creation of index template [{}] for [{}], because its creation is in progress",

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/template/TemplateUtils.java

@@ -59,9 +59,10 @@ public static void loadTemplateIntoMap(String resource, Map<String, IndexTemplat
     public static String loadTemplate(String resource, String version, String versionProperty) {
         try {
             BytesReference source = load(resource);
-            validate(source);
+            final String filteredJson = filter(source, version, versionProperty);
+            validate(new BytesArray(filteredJson));
 
-            return filter(source, version, versionProperty);
+            return filteredJson;
         } catch (Exception e) {
             throw new IllegalArgumentException("Unable to load template [" + resource + "]", e);
         }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/WatcherIndexTemplateRegistryField.java

@@ -16,7 +16,7 @@ public final class WatcherIndexTemplateRegistryField {
     // version 9: add a user field defining which user executed the watch
     // version 10: add support for foreach path in actions
     // Note: if you change this, also inform the kibana team around the watcher-ui
-    public static final String INDEX_TEMPLATE_VERSION = "10";
+    public static final int INDEX_TEMPLATE_VERSION = 10;
     public static final String HISTORY_TEMPLATE_NAME = ".watch-history-" + INDEX_TEMPLATE_VERSION;
     public static final String HISTORY_TEMPLATE_NAME_NO_ILM = ".watch-history-no-ilm-" + INDEX_TEMPLATE_VERSION;
     public static final String TRIGGERED_TEMPLATE_NAME = ".triggered_watches";

x-pack/plugin/core/src/main/resources/ilm-history.json

@@ -9,6 +9,7 @@
     "index.auto_expand_replicas": "0-1",
     "index.lifecycle.name": "ilm-history-ilm-policy",
     "index.lifecycle.rollover_alias": "ilm-history-${xpack.ilm_history.template.version}",
+    "index.hidden": true,
     "index.format": 1
   },
   "mappings": {
@@ -79,5 +80,6 @@
         }
       }
     }
-  }
+  },
+  "version": ${xpack.ilm_history.template.version}
 }

x-pack/plugin/core/src/main/resources/slm-history.json

@@ -9,6 +9,7 @@
     "index.auto_expand_replicas": "0-1",
     "index.lifecycle.name": "slm-history-ilm-policy",
     "index.lifecycle.rollover_alias": ".slm-history-${xpack.slm.template.version}",
+    "index.hidden": true,
     "index.format": 1
   },
   "mappings": {
@@ -55,5 +56,6 @@
         }
       }
     }
-  }
-}
+  },
+  "version": ${xpack.slm.template.version}
+}