Introduce an IndexSettingsProvider to inject logsdb index mode

x-pack/plugin/core/src/main/java/org/elasticsearch/datastreams/logsdb/LogsdbIndexModeSettingsProvider.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.datastreams.logsdb;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.elasticsearch.cluster.metadata.Metadata;
+import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.common.compress.CompressedXContent;
+import org.elasticsearch.common.settings.Setting;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.index.IndexMode;
+import org.elasticsearch.index.IndexSettingProvider;
+
+import java.time.Instant;
+import java.util.Arrays;
+import java.util.List;
+
+public class LogsdbIndexModeSettingsProvider implements IndexSettingProvider {
+    private static final Logger logger = LogManager.getLogger(LogsdbIndexModeSettingsProvider.class);
+    private static final PatternMatcher logsNameMatcher = PatternMatcher.forLogs();
+
+    public static final Setting<Boolean> CLUSTER_INDEX_MODE_LOGSDB_ENABLED = Setting.boolSetting(
+        "cluster.index.mode.logsdb.enabled",
+        false,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+    private boolean isLogsdbEnabled;
+
+    public LogsdbIndexModeSettingsProvider(final ClusterService clusterService) {
+        this.isLogsdbEnabled = clusterService.getSettings().getAsBoolean(CLUSTER_INDEX_MODE_LOGSDB_ENABLED.getKey(), false);
+        clusterService.getClusterSettings()
+            .addSettingsUpdateConsumer(CLUSTER_INDEX_MODE_LOGSDB_ENABLED, this::updateClusterIndexModeLogsdbEnabled);
+    }
+
+    private void updateClusterIndexModeLogsdbEnabled(boolean isLogsdbEnabled) {
+        logger.debug("LogsDB " + (isLogsdbEnabled ? "enabled" : "disabled"));
+        this.isLogsdbEnabled = isLogsdbEnabled;
+    }
+
+    @Override
+    public Settings getAdditionalIndexSettings(
+        final String indexName,
+        final String dataStreamName,
+        boolean isTimeSeries,
+        final Metadata metadata,
+        final Instant resolvedAt,
+        final Settings settings,
+        final List<CompressedXContent> combinedTemplateMappings
+    ) {
+        if (isLogsdbEnabled == false) {
+            return Settings.EMPTY;
+        }
+
+        final IndexMode indexMode = resolveIndexMode(settings.get("index.mode"));
+        if (IndexMode.STANDARD.equals(indexMode) && isLogsDataStreamOrIndexName(indexName, dataStreamName)) {
+            return Settings.builder().put("index.mode", IndexMode.LOGSDB.getName()).build();
+        }
+
+        return Settings.EMPTY;
+    }
+
+    private static boolean isLogsDataStreamOrIndexName(final String indexName, final String dataStreamName) {
+        return logsNameMatcher.matches(indexName) || logsNameMatcher.matches(dataStreamName);
+    }
+
+    private IndexMode resolveIndexMode(final String mode) {
+        if (mode == null) {
+            return IndexMode.STANDARD;
+        }
+        return Arrays.stream(IndexMode.values())
+            .filter(indexMode -> indexMode.getName().equals(mode))
+            .findFirst()
+            .orElse(IndexMode.STANDARD);
+    }
+
+}

x-pack/plugin/core/src/main/java/org/elasticsearch/datastreams/logsdb/PatternMatcher.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.datastreams.logsdb;
+
+import java.util.regex.Pattern;
+
+public class PatternMatcher {
+    private final Pattern pattern;
+
+    private PatternMatcher(final Pattern pattern) {
+        this.pattern = pattern;
+    }
+
+    public boolean matches(final String value) {
+        return value != null && pattern.matcher(value).matches();
+    }
+
+    public static PatternMatcher forLogs() {
+        return new PatternMatcher(Pattern.compile("logs-[^-]+-[^-]+"));
+    }
+}

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

@@ -32,6 +32,7 @@
 import org.elasticsearch.common.ssl.SslConfiguration;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.core.Booleans;
+import org.elasticsearch.datastreams.logsdb.LogsdbIndexModeSettingsProvider;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.features.NodeFeature;
 import org.elasticsearch.index.IndexSettingProvider;
@@ -184,6 +185,8 @@ public Void run() {
     private static SetOnce<XPackLicenseState> licenseState = new SetOnce<>();
     private static SetOnce<LicenseService> licenseService = new SetOnce<>();
 
+    private static SetOnce<ClusterService> clusterService = new SetOnce<>();
+
     public XPackPlugin(final Settings settings) {
         super();
         // FIXME: The settings might be changed after this (e.g. from "additionalSettings" method in other plugins)
@@ -231,6 +234,10 @@ protected void setEpochMillisSupplier(LongSupplier epochMillisSupplier) {
         XPackPlugin.epochMillisSupplier.set(epochMillisSupplier);
     }
 
+    protected void setClusterService(ClusterService clusterService) {
+        XPackPlugin.clusterService.set(clusterService);
+    }
+
     public static SSLService getSharedSslService() {
         final SSLService ssl = XPackPlugin.sslService.get();
         if (ssl == null) {
@@ -338,6 +345,7 @@ public Collection<?> createComponents(PluginServices services) {
         }
 
         setEpochMillisSupplier(services.threadPool()::absoluteTimeInMillis);
+        setClusterService(services.clusterService());
 
         // It is useful to override these as they are what guice is injecting into actions
         components.add(sslService);
@@ -482,7 +490,7 @@ public Collection<IndexSettingProvider> getAdditionalIndexSettingProviders(Index
         if (DiscoveryNode.isStateless(settings)) {
             return List.of();
         }
-        return Collections.singleton(new DataTier.DefaultHotAllocationSettingProvider());
+        return List.of(new DataTier.DefaultHotAllocationSettingProvider(), new LogsdbIndexModeSettingsProvider(clusterService.get()));
     }
 
     /**

x-pack/plugin/core/src/test/java/org/elasticsearch/datastreams/logsdb/PatternMatcherTests.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.datastreams.logsdb;
+
+import junit.framework.TestCase;
+
+public class PatternMatcherTests extends TestCase {
+
+    private static final PatternMatcher matcher = PatternMatcher.forLogs();
+
+    public void testMatching() {
+        assertTrue(matcher.matches("logs-apache-production"));
+        assertTrue(matcher.matches("logs-apache-123"));
+        assertTrue(matcher.matches("logs-123-production"));
+        assertTrue(matcher.matches("logs-apache.kafka-production.eu.west"));
+    }
+
+    public void testNonMatching() {
+        assertFalse(matcher.matches(null));
+        assertFalse(matcher.matches(""));
+        assertFalse(matcher.matches("logs"));
+        assertFalse(matcher.matches("logs-apache"));
+        assertFalse(matcher.matches("standard-apache-production"));
+        assertFalse(matcher.matches("logs-apache-production-eu"));
+    }
+
+}