Optionally require a valid content type for all rest requests with content (#22691)

This change adds a strict mode for xcontent parsing on the rest layer. The strict mode will be off by default for 5.x and in a separate commit will be enabled by default for 6.0. The strict mode, which can be enabled by setting `http.content_type.required: true` in 5.x, will require that all incoming rest requests have a valid and supported content type header before the request is dispatched. In the non-strict mode, the Content-Type header will be inspected and if it is not present or not valid, we will continue with auto detection of content like we have done previously.

The content type header is parsed to the matching XContentType value with the only exception being for plain text requests. This value is then passed on with the content bytes so that we can reduce the number of places where we need to auto-detect the content type.

As part of this, many transport requests and builders were updated to provide methods that
accepted the XContentType along with the bytes and the methods that would rely on auto-detection have been deprecated.

In the non-strict mode, deprecation warnings are issued whenever a request with body doesn't provide the Content-Type header.

See #19388 

1 files changed, 59 insertions, 2 deletions

diff --git a/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java b/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java
index c1db96ae7c..e7ca25e511 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/indices/template/put/PutIndexTemplateRequestBuilder.java
@@ -24,6 +24,7 @@ import org.elasticsearch.client.ElasticsearchClient;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentType;
 
 import java.util.Collections;
 import java.util.List;
@@ -100,15 +101,25 @@ public class PutIndexTemplateRequestBuilder
     }
 
     /**
-     * The settings to crete the index template with (either json/yaml/properties format)
+     * The settings to crete the index template with (either json or yaml format)
+     * @deprecated use {@link #setSettings(String, XContentType)}
      */
+    @Deprecated
     public PutIndexTemplateRequestBuilder setSettings(String source) {
         request.settings(source);
         return this;
     }
 
     /**
-     * The settings to crete the index template with (either json/yaml/properties format)
+     * The settings to crete the index template with (either json or yaml format)
+     */
+    public PutIndexTemplateRequestBuilder setSettings(String source, XContentType xContentType) {
+        request.settings(source, xContentType);
+        return this;
+    }
+
+    /**
+     * The settings to crete the index template with (either json or yaml format)
      */
     public PutIndexTemplateRequestBuilder setSettings(Map<String, Object> source) {
         request.settings(source);
@@ -120,13 +131,27 @@ public class PutIndexTemplateRequestBuilder
      *
      * @param type   The mapping type
      * @param source The mapping source
+     * @deprecated use {@link #addMapping(String, String, XContentType)}
      */
+    @Deprecated
     public PutIndexTemplateRequestBuilder addMapping(String type, String source) {
         request.mapping(type, source);
         return this;
     }
 
     /**
+     * Adds mapping that will be added when the index template gets created.
+     *
+     * @param type   The mapping type
+     * @param source The mapping source
+     * @param xContentType The type/format of the source
+     */
+    public PutIndexTemplateRequestBuilder addMapping(String type, String source, XContentType xContentType) {
+        request.mapping(type, source, xContentType);
+        return this;
+    }
+
+    /**
      * A specialized simplified mapping source method, takes the form of simple properties definition:
      * ("field1", "type=string,store=true").
      */
@@ -226,7 +251,9 @@ public class PutIndexTemplateRequestBuilder
 
     /**
      * The template source definition.
+     * @deprecated use {@link #setSource(BytesReference, XContentType)}
      */
+    @Deprecated
     public PutIndexTemplateRequestBuilder setSource(String templateSource) {
         request.source(templateSource);
         return this;
@@ -235,6 +262,16 @@ public class PutIndexTemplateRequestBuilder
     /**
      * The template source definition.
      */
+    public PutIndexTemplateRequestBuilder setSource(BytesReference templateSource, XContentType xContentType) {
+        request.source(templateSource, xContentType);
+        return this;
+    }
+
+    /**
+     * The template source definition.
+     * @deprecated use {@link #setSource(BytesReference, XContentType)}
+     */
+    @Deprecated
     public PutIndexTemplateRequestBuilder setSource(BytesReference templateSource) {
         request.source(templateSource);
         return this;
@@ -242,7 +279,9 @@ public class PutIndexTemplateRequestBuilder
 
     /**
      * The template source definition.
+     * @deprecated use {@link #setSource(byte[], XContentType)}
      */
+    @Deprecated
     public PutIndexTemplateRequestBuilder setSource(byte[] templateSource) {
         request.source(templateSource);
         return this;
@@ -251,8 +290,26 @@ public class PutIndexTemplateRequestBuilder
     /**
      * The template source definition.
      */
+    public PutIndexTemplateRequestBuilder setSource(byte[] templateSource, XContentType xContentType) {
+        request.source(templateSource, xContentType);
+        return this;
+    }
+
+    /**
+     * The template source definition.
+     * @deprecated use {@link #setSource(byte[], int, int, XContentType)}
+     */
+    @Deprecated
     public PutIndexTemplateRequestBuilder setSource(byte[] templateSource, int offset, int length) {
         request.source(templateSource, offset, length);
         return this;
     }
+
+    /**
+     * The template source definition.
+     */
+    public PutIndexTemplateRequestBuilder setSource(byte[] templateSource, int offset, int length, XContentType xContentType) {
+        request.source(templateSource, offset, length, xContentType);
+        return this;
+    }
 }