Deprecate types in get_source and exist_source (#36426)

This change adds a new untyped endpoint `{index}/_source/{id}` for both the
GET and the HEAD methods to get the source of a document or check for its
existance. It also adds deprecation warnings to RestGetSourceAction that emit
a warning when the old deprecated "type" parameter is still used. Also updating
documentation and tests where appropriate.

Relates to #35190

Author: Christoph Büscher

client/rest-high-level/src/main/java/org/elasticsearch/client/RequestConverters.java

@@ -268,8 +268,14 @@ private static Request getStyleRequest(String method, GetRequest getRequest) {
     }
 
     static Request sourceExists(GetRequest getRequest) {
-        Request request = new Request(HttpHead.METHOD_NAME, endpoint(getRequest.index(), getRequest.type(), getRequest.id(), "_source"));
-
+        String optionalType = getRequest.type();
+        String endpoint;
+        if (optionalType.equals(MapperService.SINGLE_MAPPING_NAME)) {
+            endpoint = endpoint(getRequest.index(), "_source", getRequest.id());
+        } else {
+            endpoint = endpoint(getRequest.index(), optionalType, getRequest.id(), "_source");
+        }
+        Request request = new Request(HttpHead.METHOD_NAME, endpoint);
         Params parameters = new Params(request);
         parameters.withPreference(getRequest.preference());
         parameters.withRouting(getRequest.routing());

client/rest-high-level/src/test/java/org/elasticsearch/client/RequestConvertersTests.java

@@ -73,6 +73,7 @@
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
 import org.elasticsearch.index.VersionType;
+import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.query.QueryBuilders;
 import org.elasticsearch.index.query.TermQueryBuilder;
 import org.elasticsearch.index.rankeval.PrecisionAtK;
@@ -115,6 +116,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.StringJoiner;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
@@ -156,6 +158,58 @@ public void testGetWithType() {
         getAndExistsWithTypeTest(RequestConverters::get, HttpGet.METHOD_NAME);
     }
 
+    public void testSourceExists() throws IOException {
+        doTestSourceExists((index, id) -> new GetRequest(index, id));
+    }
+
+    public void testSourceExistsWithType() throws IOException {
+        String type = frequently() ? randomAlphaOfLengthBetween(3, 10) : MapperService.SINGLE_MAPPING_NAME;
+        doTestSourceExists((index, id) -> new GetRequest(index, type, id));
+    }
+
+    private static void doTestSourceExists(BiFunction<String, String, GetRequest> requestFunction) throws IOException {
+        String index = randomAlphaOfLengthBetween(3, 10);
+        String id = randomAlphaOfLengthBetween(3, 10);
+        final GetRequest getRequest = requestFunction.apply(index, id);
+
+        Map<String, String> expectedParams = new HashMap<>();
+        if (randomBoolean()) {
+            String preference = randomAlphaOfLengthBetween(3, 10);
+            getRequest.preference(preference);
+            expectedParams.put("preference", preference);
+        }
+        if (randomBoolean()) {
+            String routing = randomAlphaOfLengthBetween(3, 10);
+            getRequest.routing(routing);
+            expectedParams.put("routing", routing);
+        }
+        if (randomBoolean()) {
+            boolean realtime = randomBoolean();
+            getRequest.realtime(realtime);
+            if (realtime == false) {
+                expectedParams.put("realtime", "false");
+            }
+        }
+        if (randomBoolean()) {
+            boolean refresh = randomBoolean();
+            getRequest.refresh(refresh);
+            if (refresh) {
+                expectedParams.put("refresh", "true");
+            }
+        }
+        Request request = RequestConverters.sourceExists(getRequest);
+        assertEquals(HttpHead.METHOD_NAME, request.getMethod());
+        String type = getRequest.type();
+        if (type.equals(MapperService.SINGLE_MAPPING_NAME)) {
+            assertEquals("/" + index + "/_source/" + id, request.getEndpoint());
+        } else {
+            assertEquals("/" + index + "/" + type + "/" + id + "/_source", request.getEndpoint());
+        }
+
+        assertEquals(expectedParams, request.getParameters());
+        assertNull(request.getEntity());
+    }
+
     public void testMultiGet() throws IOException {
         Map<String, String> expectedParams = new HashMap<>();
         MultiGetRequest multiGetRequest = new MultiGetRequest();

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/CRUDDocumentationIT.java

@@ -1265,7 +1265,6 @@ public void testGet() throws Exception {
             assertEquals(3, getResponse.getSourceAsMap().size());
             //tag::get-response
             String index = getResponse.getIndex();
-            String type = getResponse.getType();
             String id = getResponse.getId();
             if (getResponse.isExists()) {
                 long version = getResponse.getVersion();

docs/reference/docs/get.asciidoc

@@ -1,9 +1,9 @@
 [[docs-get]]
 == Get API
 
-The get API allows to get a typed JSON document from the index based on
+The get API allows to get a JSON document from the index based on
 its id. The following example gets a JSON document from an index called
-twitter, under a type called `_doc`, with id valued 0:
+twitter with id valued 0:
 
 [source,js]
 --------------------------------------------------
@@ -34,7 +34,7 @@ The result of the above get operation is:
 --------------------------------------------------
 // TESTRESPONSE[s/"_seq_no" : \d+/"_seq_no" : $body._seq_no/ s/"_primary_term" : 1/"_primary_term" : $body._primary_term/]
 
-The above result includes the `_index`, `_type`, `_id` and `_version`
+The above result includes the `_index`, `_id` and `_version`
 of the document we wish to retrieve, including the actual `_source`
 of the document if it could be found (as indicated by the `found`
 field in the response).
@@ -223,13 +223,13 @@ will fail.
 [[_source]]
 === Getting the +_source+ directly
 
-Use the `/{index}/{type}/{id}/_source` endpoint to get
+Use the `/{index}/_source/{id}` endpoint to get
 just the `_source` field of the document,
 without any additional content around it. For example:
 
 [source,js]
 --------------------------------------------------
-GET twitter/_doc/1/_source
+GET twitter/_source/1
 --------------------------------------------------
 // CONSOLE
 // TEST[continued]
@@ -238,7 +238,7 @@ You can also use the same source filtering parameters to control which parts of
 
 [source,js]
 --------------------------------------------------
-GET twitter/_doc/1/_source?_source_includes=*.id&_source_excludes=entities'
+GET twitter/_source/1/?_source_includes=*.id&_source_excludes=entities'
 --------------------------------------------------
 // CONSOLE
 // TEST[continued]
@@ -248,7 +248,7 @@ An existing document will not have a _source if it is disabled in the <<mapping-
 
 [source,js]
 --------------------------------------------------
-HEAD twitter/_doc/1/_source
+HEAD twitter/_source/1
 --------------------------------------------------
 // CONSOLE
 // TEST[continued]

modules/transport-netty4/src/test/java/org/elasticsearch/rest/Netty4HeadBodyIsEmptyIT.java

@@ -149,8 +149,8 @@ public void testTemplateExists() throws IOException {
 
     public void testGetSourceAction() throws IOException {
         createTestDoc();
-        headTestCase("/test/test/1/_source", emptyMap(), greaterThan(0));
-        headTestCase("/test/test/2/_source", emptyMap(), NOT_FOUND.getStatus(), greaterThan(0));
+        headTestCase("/test/_source/1", emptyMap(), greaterThan(0));
+        headTestCase("/test/_source/2", emptyMap(), NOT_FOUND.getStatus(), greaterThan(0));
 
         try (XContentBuilder builder = jsonBuilder()) {
             builder.startObject();
@@ -175,7 +175,7 @@ public void testGetSourceAction() throws IOException {
             request.setJsonEntity(Strings.toString(builder));
             client().performRequest(request);
             createTestDoc("test-no-source", "test-no-source");
-            headTestCase("/test-no-source/test-no-source/1/_source", emptyMap(), NOT_FOUND.getStatus(), greaterThan(0));
+            headTestCase("/test-no-source/_source/1", emptyMap(), NOT_FOUND.getStatus(), greaterThan(0));
         }
     }
 

rest-api-spec/src/main/resources/rest-api-spec/api/exists_source.json

@@ -3,8 +3,8 @@
     "documentation": "http://www.elastic.co/guide/en/elasticsearch/reference/master/docs-get.html",
     "methods": ["HEAD"],
     "url": {
-      "path": "/{index}/{type}/{id}/_source",
-      "paths": ["/{index}/{type}/{id}/_source"],
+      "path": "/{index}/_source/{id}",
+      "paths": ["/{index}/_source/{id}", "/{index}/{type}/{id}/_source"],
       "parts": {
         "id": {
           "type" : "string",
@@ -18,8 +18,8 @@
         },
         "type": {
           "type" : "string",
-          "required" : true,
-          "description" : "The type of the document; use `_all` to fetch the first document matching the ID across all types"
+          "required" : false,
+          "description" : "The type of the document; deprecated and optional starting with 7.0"
         }
       },
       "params": {

rest-api-spec/src/main/resources/rest-api-spec/api/get_source.json

@@ -3,8 +3,8 @@
     "documentation": "http://www.elastic.co/guide/en/elasticsearch/reference/master/docs-get.html",
     "methods": ["GET"],
     "url": {
-      "path": "/{index}/{type}/{id}/_source",
-      "paths": ["/{index}/{type}/{id}/_source"],
+      "path": "/{index}/_source/{id}",
+      "paths": ["/{index}/_source/{id}", "/{index}/{type}/{id}/_source"],
       "parts": {
         "id": {
           "type" : "string",
@@ -18,8 +18,8 @@
         },
         "type": {
           "type" : "string",
-          "required" : true,
-          "description" : "The type of the document; use `_all` to fetch the first document matching the ID across all types"
+          "required" : false,
+          "description" : "The type of the document; deprecated and optional starting with 7.0"
         }
       },
       "params": {

rest-api-spec/src/main/resources/rest-api-spec/test/get_source/10_basic.yml

@@ -1,24 +1,26 @@
 ---
 "Basic":
+
+  - skip:
+      version: " - 6.99.99"
+      reason: types are required in requests before 7.0.0
+
   - do:
       index:
         index: test_1
-        type:  test
         id:    1
         body:  { "foo": "bar" }
 
   - do:
       get_source:
         index: test_1
-        type:  test
         id:    1
 
   - match: { '':  { foo: bar } }
 
   - do:
       get_source:
         index: test_1
-        type: _all
         id:    1
 
   - match: { '':  { foo: bar } }

rest-api-spec/src/main/resources/rest-api-spec/test/get_source/11_basic_with_types.yml

@@ -0,0 +1,17 @@
+---
+"Basic with types":
+
+  - do:
+      index:
+        index: test_1
+        type:  test
+        id:    1
+        body:  { "foo": "bar" }
+
+  - do:
+      get_source:
+        index: test_1
+        type:  test
+        id:    1
+
+  - match: { '':  { foo: bar } }

rest-api-spec/src/main/resources/rest-api-spec/test/get_source/15_default_values.yml

@@ -1,5 +1,11 @@
 ---
 "Default values":
+
+
+  - skip:
+      version: " - 6.99.99"
+      reason: types are required in requests before 7.0.0
+
   - do:
       index:
         index: test_1
@@ -10,7 +16,6 @@
   - do:
       get_source:
         index: test_1
-        type: _all
         id:    1
 
   - match: { '':  { foo: bar } }