From e142d693c725f6315cd9a671681fa9a687666479 Mon Sep 17 00:00:00 2001
From: Lee Hinman <dakrone@users.noreply.github.com>
Date: Mon, 8 Jun 2020 14:21:26 -0600
Subject: [PATCH] [7.8] Throw exception on duplicate mappings metadata fields
 (#57840)

This is a backport of #57835

In #57701 we changed mappings merging so that duplicate fields specified in mappings caused an
exception during validation. This change makes the same exception thrown when metadata fields are
duplicated. This will allow us to be strict currently with plans to make the merging more
fine-grained in a later release.
---
 .../cluster/metadata/MetadataCreateIndexService.java     | 8 ++------
 .../cluster/metadata/MetadataIndexTemplateService.java   | 9 ++++-----
 .../metadata/MetadataCreateIndexServiceTests.java        | 2 ++
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexService.java b/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexService.java
index d9693258f41d7..9951be06c010f 100644
--- a/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexService.java
+++ b/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexService.java
@@ -585,9 +585,7 @@ static Map<String, Map<String, Object>> parseV2Mappings(String mappingsJson, Lis
                 Map<String, Object> innerTemplateNonProperties = new HashMap<>(innerTemplateMapping);
                 Map<String, Object> maybeProperties = (Map<String, Object>) innerTemplateNonProperties.remove("properties");
 
-                nonProperties = removeDuplicatedDynamicTemplates(nonProperties, innerTemplateNonProperties);
-                XContentHelper.mergeDefaults(innerTemplateNonProperties, nonProperties);
-                nonProperties = innerTemplateNonProperties;
+                nonProperties = mergeFailingOnReplacement(nonProperties, innerTemplateNonProperties);
 
                 if (maybeProperties != null) {
                     properties = mergeFailingOnReplacement(properties, maybeProperties);
@@ -600,9 +598,7 @@ static Map<String, Map<String, Object>> parseV2Mappings(String mappingsJson, Lis
             Map<String, Object> innerRequestNonProperties = new HashMap<>(innerRequestMappings);
             Map<String, Object> maybeRequestProperties = (Map<String, Object>) innerRequestNonProperties.remove("properties");
 
-            nonProperties = removeDuplicatedDynamicTemplates(nonProperties, innerRequestMappings);
-            XContentHelper.mergeDefaults(innerRequestNonProperties, nonProperties);
-            nonProperties = innerRequestNonProperties;
+            nonProperties = mergeFailingOnReplacement(nonProperties, innerRequestNonProperties);
 
             if (maybeRequestProperties != null) {
                 properties = mergeFailingOnReplacement(properties, maybeRequestProperties);
diff --git a/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java b/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java
index 3c2dd9e55910b..b8cd1a6e7429a 100644
--- a/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java
+++ b/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java
@@ -949,12 +949,11 @@ private static void validateCompositeTemplate(final ClusterState state,
                 // Parse mappings to ensure they are valid after being composed
                 List<CompressedXContent> mappings = resolveMappings(stateWithIndex, templateName);
                 try {
+                    Map<String, Map<String, Object>> finalMappings =
+                        MetadataCreateIndexService.parseV2Mappings("{}", mappings, xContentRegistry);
                     MapperService dummyMapperService = tempIndexService.mapperService();
-                    for (CompressedXContent mapping : mappings) {
-                        // TODO: Eventually change this to:
-                        // dummyMapperService.merge(MapperService.SINGLE_MAPPING_NAME, mapping, MergeReason.INDEX_TEMPLATE);
-                        dummyMapperService.merge(MapperService.SINGLE_MAPPING_NAME, mapping, MergeReason.MAPPING_UPDATE);
-                    }
+                        // TODO: Eventually change this to use MergeReason.INDEX_TEMPLATE
+                        dummyMapperService.merge(finalMappings, MergeReason.MAPPING_UPDATE);
                 } catch (Exception e) {
                     throw new IllegalArgumentException("invalid composite mappings for [" + templateName + "]", e);
                 }
diff --git a/server/src/test/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexServiceTests.java b/server/src/test/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexServiceTests.java
index 132eca91a6761..859b99da11505 100644
--- a/server/src/test/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexServiceTests.java
+++ b/server/src/test/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexServiceTests.java
@@ -1174,6 +1174,7 @@ public void testDedupTemplateDynamicTemplates() throws Exception {
             dynamicMapping.get("path_match"), is("docker.container.labels.*"));
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/pull/57393")
     public void testDedupRequestDynamicTemplates() throws Exception {
         String requestMappingJson = "{\"_doc\":{\"_source\":{\"enabled\": false}, \"dynamic_templates\": [" +
             "{\n" +
@@ -1235,6 +1236,7 @@ public void testDedupRequestDynamicTemplates() throws Exception {
         assertThat(mapping.get("type"), is("keyword"));
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/pull/57393")
     public void testMultipleComponentTemplatesDefineSameDynamicTemplate() throws Exception {
         String ct1Mapping = "{\"_doc\":{\"_source\":{\"enabled\": false}, \"dynamic_templates\": [" +
             "{\n" +