QA: Node name selector for yml tests

In 6.x we need to be able to select which node receives a request by
node name. This implements that.

Relates to elastic#30523

rest-api-spec/src/main/resources/rest-api-spec/test/README.asciidoc

@@ -198,9 +198,7 @@ header. The warnings must match exactly. Using it looks like this:
 ....
 
 If the arguments to `do` include `node_selector` then the request is only
-sent to nodes that match the `node_selector`. Currently only the `version`
-selector is supported and it has the same logic as the `version` field in
-`skip`. It looks like this:
+sent to nodes that match the `node_selector`. It looks like this:
 
 ....
 "test id":
@@ -216,6 +214,14 @@ selector is supported and it has the same logic as the `version` field in
           body:   { foo: bar }
 ....
 
+If you list multiple selectors then the request will only go to nodes that
+match all of those selectors. The following selectors are supported:
+* `version`: Only nodes who's version is within the range will receive the
+request. The syntax for the pattern is the same as when `version` is within
+`skip`.
+* `name`: Only nodes who's name matches the name exactly will receive the
+request.
+
 === `set`
 
 For some tests, it is necessary to extract a value from the previous `response`, in

test/framework/src/main/java/org/elasticsearch/test/rest/yaml/section/DoSection.java

@@ -370,6 +370,27 @@ private String formatStatusCodeMessage(ClientYamlTestResponse restTestResponse,
 
     private static NodeSelector buildNodeSelector(XContentLocation location, String name, String value) {
         switch (name) {
+        case "name":
+            return new NodeSelector() {
+                @Override
+                public void select(Iterable<Node> nodes) {
+                    for (Iterator<Node> itr = nodes.iterator(); itr.hasNext();) {
+                        Node node = itr.next();
+                        if (node.getName() == null) {
+                            throw new IllegalStateException("expected [name] metadata to be set but got "
+                                    + node);
+                        }
+                        if (false == value.equals(node.getName())) {
+                            itr.remove();
+                        }
+                    }
+                }
+
+                @Override
+                public String toString() {
+                    return "name is [" + value + "]";
+                }
+            };
         case "version":
             Version[] range = SkipSection.parseVersionRange(value);
             return new NodeSelector() {

test/framework/src/test/java/org/elasticsearch/test/rest/yaml/section/DoSectionTests.java

@@ -511,7 +511,7 @@ public void testParseDoSectionExpectedWarnings() throws Exception {
                 "just one entry this time")));
     }
 
-    public void testNodeSelector() throws IOException {
+    public void testNodeSelectorByVersion() throws IOException {
         parser = createParser(YamlXContent.yamlXContent,
                 "node_selector:\n" +
                 "    version: 5.2.0-6.0.0\n" +
@@ -521,10 +521,10 @@ public void testNodeSelector() throws IOException {
 
         DoSection doSection = DoSection.parse(parser);
         assertNotSame(NodeSelector.ANY, doSection.getApiCallSection().getNodeSelector());
-        Node v170 = nodeWithVersion("1.7.0");
-        Node v521 = nodeWithVersion("5.2.1");
-        Node v550 = nodeWithVersion("5.5.0");
-        Node v612 = nodeWithVersion("6.1.2");
+        Node v170 = new Node(new HttpHost("dummy"), null, null, "1.7.0", null);
+        Node v521 = new Node(new HttpHost("dummy"), null, null, "5.2.1", null);
+        Node v550 = new Node(new HttpHost("dummy"), null, null, "5.5.0", null);
+        Node v612 = new Node(new HttpHost("dummy"), null, null, "6.1.2", null);
         List<Node> nodes = new ArrayList<>();
         nodes.add(v170);
         nodes.add(v521);
@@ -541,8 +541,61 @@ public void testNodeSelector() throws IOException {
                 emptyList(), emptyMap(), doSection.getApiCallSection().getNodeSelector());
     }
 
-    private Node nodeWithVersion(String version) {
-        return new Node(new HttpHost("dummy"), null, null, version, null);
+    public void testNodeSelectorByName() throws IOException {
+        parser = createParser(YamlXContent.yamlXContent,
+                "node_selector:\n" +
+                "    name: cat\n" +
+                "indices.get_field_mapping:\n" +
+                "    index: test_index"
+        );
+
+        DoSection doSection = DoSection.parse(parser);
+        assertNotSame(NodeSelector.ANY, doSection.getApiCallSection().getNodeSelector());
+        Node cat = new Node(new HttpHost("dummy"), null, "cat", null, null);
+        Node dog = new Node(new HttpHost("dummy"), null, "dog", null, null);
+        Node pig = new Node(new HttpHost("dummy"), null, "pig", null, null);
+        List<Node> nodes = new ArrayList<>();
+        nodes.add(cat);
+        nodes.add(dog);
+        nodes.add(pig);
+        doSection.getApiCallSection().getNodeSelector().select(nodes);
+        assertEquals(Arrays.asList(cat), nodes);
+        ClientYamlTestExecutionContext context = mock(ClientYamlTestExecutionContext.class);
+        ClientYamlTestResponse mockResponse = mock(ClientYamlTestResponse.class);
+        when(context.callApi("indices.get_field_mapping", singletonMap("index", "test_index"),
+                emptyList(), emptyMap(), doSection.getApiCallSection().getNodeSelector())).thenReturn(mockResponse);
+        doSection.execute(context);
+        verify(context).callApi("indices.get_field_mapping", singletonMap("index", "test_index"),
+                emptyList(), emptyMap(), doSection.getApiCallSection().getNodeSelector());
+    }
+
+    public void testNodeSelectorByTwoThings() throws IOException {
+        parser = createParser(YamlXContent.yamlXContent,
+                "node_selector:\n" +
+                "    name: cat\n" +
+                "    version: 5.2.0-6.0.0\n" +
+                "indices.get_field_mapping:\n" +
+                "    index: test_index"
+        );
+
+        DoSection doSection = DoSection.parse(parser);
+        assertNotSame(NodeSelector.ANY, doSection.getApiCallSection().getNodeSelector());
+        Node cat = new Node(new HttpHost("dummy"), null, "cat", "5.2.1", null);
+        Node badName = new Node(new HttpHost("dummy"), null, "dog", "5.2.1", null);
+        Node badVersion = new Node(new HttpHost("dummy"), null, "cat", "6.1.2", null);
+        List<Node> nodes = new ArrayList<>();
+        nodes.add(cat);
+        nodes.add(badName);
+        nodes.add(badVersion);
+        doSection.getApiCallSection().getNodeSelector().select(nodes);
+        assertEquals(Arrays.asList(cat), nodes);
+        ClientYamlTestExecutionContext context = mock(ClientYamlTestExecutionContext.class);
+        ClientYamlTestResponse mockResponse = mock(ClientYamlTestResponse.class);
+        when(context.callApi("indices.get_field_mapping", singletonMap("index", "test_index"),
+                emptyList(), emptyMap(), doSection.getApiCallSection().getNodeSelector())).thenReturn(mockResponse);
+        doSection.execute(context);
+        verify(context).callApi("indices.get_field_mapping", singletonMap("index", "test_index"),
+                emptyList(), emptyMap(), doSection.getApiCallSection().getNodeSelector());
     }
 
     private void assertJsonEquals(Map<String, Object> actual, String expected) throws IOException {