Move xpack template resources to an isolated module (elastic#97763)

Xpack core contains dozens of templates. These files are loaded via a
shared template utils method. While they should ideally be moved to
their appropriate modules, that would be large undertaking. This commit
moves these resources to a single module for xpack core (which may be
overriden by serverless).

Author: rjernst

x-pack/plugin/core/build.gradle

@@ -41,14 +41,15 @@ dependencies {
   api "org.apache.httpcomponents:httpcore:${versions.httpcore}"
   api "org.apache.httpcomponents:httpcore-nio:${versions.httpcore}"
   api "org.apache.httpcomponents:httpasyncclient:${versions.httpasyncclient}"
-
   api "commons-logging:commons-logging:${versions.commonslogging}"
   api "org.apache.logging.log4j:log4j-1.2-api:${versions.log4j}"
   api "commons-codec:commons-codec:${versions.commonscodec}"
 
   // security deps
   api 'com.unboundid:unboundid-ldapsdk:6.0.3'
 
+  implementation project(":x-pack:plugin:core:template-resources")
+
   testImplementation "org.elasticsearch:mocksocket:${versions.mocksocket}"
   testImplementation "org.apache.logging.log4j:log4j-slf4j-impl:${versions.log4j}" // this might suffer from https://github.com/elastic/elasticsearch/issues/93714
   testImplementation "org.slf4j:slf4j-api:${versions.slf4j}"

x-pack/plugin/core/src/main/java/module-info.java

@@ -21,6 +21,7 @@
     requires org.apache.lucene.join;
     requires unboundid.ldapsdk;
     requires org.elasticsearch.tdigest;
+    requires org.elasticsearch.xcore.templates;
 
     exports org.elasticsearch.index.engine.frozen;
     exports org.elasticsearch.license;

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

@@ -14,19 +14,15 @@
 import org.elasticsearch.cluster.metadata.ItemUsage;
 import org.elasticsearch.cluster.metadata.MetadataIndexTemplateService;
 import org.elasticsearch.common.bytes.BytesArray;
-import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.compress.NotXContentException;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentHelper;
-import org.elasticsearch.core.Streams;
 import org.elasticsearch.xcontent.NamedXContentRegistry;
 import org.elasticsearch.xcontent.XContentParser;
 import org.elasticsearch.xcontent.XContentParserConfiguration;
 import org.elasticsearch.xcontent.XContentType;
+import org.elasticsearch.xpack.core.template.resources.TemplateResources;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Pattern;
@@ -49,13 +45,13 @@ public static LifecyclePolicy loadPolicy(
         NamedXContentRegistry xContentRegistry
     ) {
         try {
-            BytesReference source = load(resource);
+            String source = TemplateResources.load(resource);
             source = replaceVariables(source, variables);
             validate(source);
 
             try (
                 XContentParser parser = XContentType.JSON.xContent()
-                    .createParser(XContentParserConfiguration.EMPTY.withRegistry(xContentRegistry), source.utf8ToString())
+                    .createParser(XContentParserConfiguration.EMPTY.withRegistry(xContentRegistry), source)
             ) {
                 LifecyclePolicy policy = LifecyclePolicy.parse(parser, name);
                 policy.validate();
@@ -66,24 +62,11 @@ public static LifecyclePolicy loadPolicy(
         }
     }
 
-    /**
-     * Loads a resource from the classpath and returns it as a {@link BytesReference}
-     */
-    private static BytesReference load(String name) throws IOException {
-        try (InputStream is = LifecyclePolicyUtils.class.getResourceAsStream(name)) {
-            try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
-                Streams.copy(is, out);
-                return new BytesArray(out.toByteArray());
-            }
-        }
-    }
-
-    private static BytesReference replaceVariables(BytesReference input, Map<String, String> variables) {
-        String template = input.utf8ToString();
+    private static String replaceVariables(String template, Map<String, String> variables) {
         for (Map.Entry<String, String> variable : variables.entrySet()) {
             template = replaceVariable(template, variable.getKey(), variable.getValue());
         }
-        return new BytesArray(template);
+        return template;
     }
 
     /**
@@ -96,13 +79,13 @@ public static String replaceVariable(String input, String variable, String value
     /**
      * Parses and validates that the source is not empty.
      */
-    private static void validate(BytesReference source) {
+    private static void validate(String source) {
         if (source == null) {
             throw new ElasticsearchParseException("policy must not be null");
         }
 
         try {
-            XContentHelper.convertToMap(source, false, XContentType.JSON).v2();
+            XContentHelper.convertToMap(new BytesArray(source), false, XContentType.JSON).v2();
         } catch (NotXContentException e) {
             throw new ElasticsearchParseException("policy must not be empty");
         } catch (Exception e) {

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

@@ -29,11 +29,7 @@ public static String indexName() {
     }
 
     public static String mapping() {
-        return TemplateUtils.loadTemplate(
-            "/org/elasticsearch/xpack/core/ml/config_index_mappings.json",
-            Version.CURRENT.toString(),
-            MAPPINGS_VERSION_VARIABLE
-        );
+        return TemplateUtils.loadTemplate("/ml/config_index_mappings.json", Version.CURRENT.toString(), MAPPINGS_VERSION_VARIABLE);
     }
 
     public static Settings settings() {

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

@@ -27,11 +27,7 @@ public static String indexName() {
     }
 
     public static String mapping() {
-        return TemplateUtils.loadTemplate(
-            "/org/elasticsearch/xpack/core/ml/meta_index_mappings.json",
-            Version.CURRENT.toString(),
-            MAPPINGS_VERSION_VARIABLE
-        );
+        return TemplateUtils.loadTemplate("/ml/meta_index_mappings.json", Version.CURRENT.toString(), MAPPINGS_VERSION_VARIABLE);
     }
 
     public static Settings settings() {

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

@@ -36,11 +36,7 @@ public static String wrappedMapping() {
     }
 
     public static String mapping() {
-        return TemplateUtils.loadTemplate(
-            "/org/elasticsearch/xpack/core/ml/stats_index_mappings.json",
-            Version.CURRENT.toString(),
-            MAPPINGS_VERSION_VARIABLE
-        );
+        return TemplateUtils.loadTemplate("/ml/stats_index_mappings.json", Version.CURRENT.toString(), MAPPINGS_VERSION_VARIABLE);
     }
 
     public static String indexPattern() {

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/annotations/AnnotationIndex.java

@@ -208,10 +208,6 @@ public static void createAnnotationsIndexIfNecessary(
     }
 
     public static String annotationsMapping() {
-        return TemplateUtils.loadTemplate(
-            "/org/elasticsearch/xpack/core/ml/annotations_index_mappings.json",
-            Version.CURRENT.toString(),
-            MAPPINGS_VERSION_VARIABLE
-        );
+        return TemplateUtils.loadTemplate("/ml/annotations_index_mappings.json", Version.CURRENT.toString(), MAPPINGS_VERSION_VARIABLE);
     }
 }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/inference/persistence/InferenceIndexConstants.java

@@ -46,11 +46,7 @@ public final class InferenceIndexConstants {
     private static final String MAPPINGS_VERSION_VARIABLE = "xpack.ml.version";
 
     public static String mapping() {
-        return TemplateUtils.loadTemplate(
-            "/org/elasticsearch/xpack/core/ml/inference_index_mappings.json",
-            Version.CURRENT.toString(),
-            MAPPINGS_VERSION_VARIABLE
-        );
+        return TemplateUtils.loadTemplate("/ml/inference_index_mappings.json", Version.CURRENT.toString(), MAPPINGS_VERSION_VARIABLE);
     }
 
     public static String nativeDefinitionStore() {

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/job/persistence/AnomalyDetectorsIndex.java

@@ -28,7 +28,7 @@
 public final class AnomalyDetectorsIndex {
 
     private static final String RESULTS_MAPPINGS_VERSION_VARIABLE = "xpack.ml.version";
-    private static final String RESOURCE_PATH = "/org/elasticsearch/xpack/core/ml/anomalydetection/";
+    private static final String RESOURCE_PATH = "/ml/anomalydetection/";
 
     private AnomalyDetectorsIndex() {}
 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/notifications/NotificationsIndex.java

@@ -13,7 +13,7 @@ public final class NotificationsIndex {
 
     public static final String NOTIFICATIONS_INDEX = ".ml-notifications-000002";
 
-    private static final String RESOURCE_PATH = "/org/elasticsearch/xpack/core/ml/";
+    private static final String RESOURCE_PATH = "/ml/";
     private static final String MAPPINGS_VERSION_VARIABLE = "xpack.ml.version";
 
     private NotificationsIndex() {}