Only allow retrieving a single index or component template (#54694)

* Only allow retrieving a single index or component template

This changes the Index Template v2 APIs to only allow retrieving a single "named" entity, where the
named entity can be nothing (return everything), a wildcard (return the ones that match), or the
name of a template.

Relates to #53101

* Throw exception when resource is not found

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

server/src/main/java/org/elasticsearch/action/admin/indices/template/get/GetComponentTemplateAction.java

@@ -24,8 +24,8 @@ import org.elasticsearch.action.ActionResponse;
 import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.support.master.MasterNodeReadRequest;
 import org.elasticsearch.cluster.metadata.ComponentTemplate;
+import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ToXContentObject;
@@ -36,8 +36,6 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 
-import static org.elasticsearch.action.ValidateActions.addValidationError;
-
 /**
  * Action to retrieve one or more component templates
  */
@@ -55,53 +53,44 @@ public class GetComponentTemplateAction extends ActionType<GetComponentTemplateA
      */
     public static class Request extends MasterNodeReadRequest<Request> {
 
-        private String[] names;
+        @Nullable
+        private String name;
 
         public Request() { }
 
-        public Request(String... names) {
-            this.names = names;
+        public Request(String name) {
+            this.name = name;
         }
 
         public Request(StreamInput in) throws IOException {
             super(in);
-            names = in.readStringArray();
+            name = in.readOptionalString();
         }
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             super.writeTo(out);
-            out.writeStringArray(names);
+            out.writeOptionalString(name);
         }
 
         @Override
         public ActionRequestValidationException validate() {
-            ActionRequestValidationException validationException = null;
-            if (names == null) {
-                validationException = addValidationError("names is null or empty", validationException);
-            } else {
-                for (String name : names) {
-                    if (name == null || Strings.hasText(name) == false) {
-                        validationException = addValidationError("name is missing", validationException);
-                    }
-                }
-            }
-            return validationException;
+            return null;
         }
 
         /**
-         * Sets the names of the component templates.
+         * Sets the name of the component templates.
          */
-        public Request names(String... names) {
-            this.names = names;
+        public Request name(String name) {
+            this.name = name;
             return this;
         }
 
         /**
-         * The names of the component templates.
+         * The name of the component templates.
          */
-        public String[] names() {
-            return this.names;
+        public String name() {
+            return this.name;
         }
     }
 

server/src/main/java/org/elasticsearch/action/admin/indices/template/get/GetIndexTemplateV2Action.java

@@ -24,21 +24,18 @@ import org.elasticsearch.action.ActionResponse;
 import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.support.master.MasterNodeReadRequest;
 import org.elasticsearch.cluster.metadata.IndexTemplateV2;
+import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ToXContentObject;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 
-import static org.elasticsearch.action.ValidateActions.addValidationError;
-
 public class GetIndexTemplateV2Action extends ActionType<GetIndexTemplateV2Action.Response> {
 
     public static final GetIndexTemplateV2Action INSTANCE = new GetIndexTemplateV2Action();
@@ -53,58 +50,49 @@ public class GetIndexTemplateV2Action extends ActionType<GetIndexTemplateV2Actio
      */
     public static class Request extends MasterNodeReadRequest<Request> {
 
-        private String[] names;
+        @Nullable
+        private String name;
 
         public Request() { }
 
-        public Request(String... names) {
-            this.names = names;
+        public Request(@Nullable String name) {
+            this.name = name;
         }
 
         public Request(StreamInput in) throws IOException {
             super(in);
-            names = in.readStringArray();
+            name = in.readOptionalString();
         }
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             super.writeTo(out);
-            out.writeStringArray(names);
+            out.writeOptionalString(name);
         }
 
         @Override
         public ActionRequestValidationException validate() {
-            ActionRequestValidationException validationException = null;
-            if (names == null) {
-                validationException = addValidationError("names is null or empty", validationException);
-            } else {
-                for (String name : names) {
-                    if (name == null || Strings.hasText(name) == false) {
-                        validationException = addValidationError("name is missing", validationException);
-                    }
-                }
-            }
-            return validationException;
+            return null;
         }
 
         /**
-         * Sets the names of the index templates.
+         * Sets the name of the index template.
          */
-        public Request names(String... names) {
-            this.names = names;
+        public Request name(String name) {
+            this.name = name;
             return this;
         }
 
         /**
-         * The names of the index templates.
+         * The name of the index templates.
          */
-        public String[] names() {
-            return this.names;
+        public String name() {
+            return this.name;
         }
 
         @Override
         public int hashCode() {
-            return Arrays.hashCode(names);
+            return Objects.hash(name);
         }
 
         @Override
@@ -116,7 +104,7 @@ public class GetIndexTemplateV2Action extends ActionType<GetIndexTemplateV2Actio
                 return false;
             }
             Request other = (Request) obj;
-            return Arrays.equals(other.names, this.names);
+            return Objects.equals(name, other.name);
         }
     }
 

server/src/main/java/org/elasticsearch/action/admin/indices/template/get/TransportGetComponentTemplateAction.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.action.admin.indices.template.get;
 
+import org.elasticsearch.ResourceNotFoundException;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.master.TransportMasterNodeReadAction;
@@ -71,22 +72,23 @@ public class TransportGetComponentTemplateAction extends
         Map<String, ComponentTemplate> allTemplates = state.metadata().componentTemplates();
 
         // If we did not ask for a specific name, then we return all templates
-        if (request.names().length == 0) {
+        if (request.name() == null) {
             listener.onResponse(new GetComponentTemplateAction.Response(allTemplates));
             return;
         }
 
         final Map<String, ComponentTemplate> results = new HashMap<>();
-        for (String name : request.names()) {
-            if (Regex.isSimpleMatchPattern(name)) {
-                for (Map.Entry<String, ComponentTemplate> entry : allTemplates.entrySet()) {
-                    if (Regex.simpleMatch(name, entry.getKey())) {
-                        results.put(entry.getKey(), entry.getValue());
-                    }
+        String name = request.name();
+        if (Regex.isSimpleMatchPattern(name)) {
+            for (Map.Entry<String, ComponentTemplate> entry : allTemplates.entrySet()) {
+                if (Regex.simpleMatch(name, entry.getKey())) {
+                    results.put(entry.getKey(), entry.getValue());
                 }
-            } else if (allTemplates.containsKey(name)) {
-                results.put(name, allTemplates.get(name));
             }
+        } else if (allTemplates.containsKey(name)) {
+            results.put(name, allTemplates.get(name));
+        } else {
+            throw new ResourceNotFoundException("component template matching [" + request.name() + "] not found");
         }
 
         listener.onResponse(new GetComponentTemplateAction.Response(results));

server/src/main/java/org/elasticsearch/action/admin/indices/template/get/TransportGetIndexTemplateV2Action.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.action.admin.indices.template.get;
 
+import org.elasticsearch.ResourceNotFoundException;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.master.TransportMasterNodeReadAction;
@@ -71,22 +72,23 @@ public class TransportGetIndexTemplateV2Action
         Map<String, IndexTemplateV2> allTemplates = state.metadata().templatesV2();
 
         // If we did not ask for a specific name, then we return all templates
-        if (request.names().length == 0) {
+        if (request.name() == null) {
             listener.onResponse(new GetIndexTemplateV2Action.Response(allTemplates));
             return;
         }
 
         final Map<String, IndexTemplateV2> results = new HashMap<>();
-        for (String name : request.names()) {
-            if (Regex.isSimpleMatchPattern(name)) {
-                for (Map.Entry<String, IndexTemplateV2> entry : allTemplates.entrySet()) {
-                    if (Regex.simpleMatch(name, entry.getKey())) {
-                        results.put(entry.getKey(), entry.getValue());
-                    }
+        String name = request.name();
+        if (Regex.isSimpleMatchPattern(name)) {
+            for (Map.Entry<String, IndexTemplateV2> entry : allTemplates.entrySet()) {
+                if (Regex.simpleMatch(name, entry.getKey())) {
+                    results.put(entry.getKey(), entry.getValue());
                 }
-            } else if (allTemplates.containsKey(name)) {
-                results.put(name, allTemplates.get(name));
             }
+        } else if (allTemplates.containsKey(name)) {
+            results.put(name, allTemplates.get(name));
+        } else {
+            throw new ResourceNotFoundException("index template matching [" + request.name() + "] not found");
         }
 
         listener.onResponse(new GetIndexTemplateV2Action.Response(results));

server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestGetComponentTemplateAction.java

@@ -21,7 +21,6 @@ package org.elasticsearch.rest.action.admin.indices;
 
 import org.elasticsearch.action.admin.indices.template.get.GetComponentTemplateAction;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
@@ -54,14 +53,13 @@ public class RestGetComponentTemplateAction extends BaseRestHandler {
 
     @Override
     public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
-        final String[] names = Strings.splitStringByCommaToArray(request.param("name"));
 
-        final GetComponentTemplateAction.Request getRequest = new GetComponentTemplateAction.Request(names);
+        final GetComponentTemplateAction.Request getRequest = new GetComponentTemplateAction.Request(request.param("name"));
 
         getRequest.local(request.paramAsBoolean("local", getRequest.local()));
         getRequest.masterNodeTimeout(request.paramAsTime("master_timeout", getRequest.masterNodeTimeout()));
 
-        final boolean implicitAll = getRequest.names().length == 0;
+        final boolean implicitAll = getRequest.name() == null;
 
         return channel ->
             client.execute(GetComponentTemplateAction.INSTANCE, getRequest, new RestToXContentListener<>(channel) {

server/src/main/java/org/elasticsearch/rest/action/admin/indices/RestGetIndexTemplateV2Action.java

@@ -21,7 +21,6 @@ package org.elasticsearch.rest.action.admin.indices;
 
 import org.elasticsearch.action.admin.indices.template.get.GetIndexTemplateV2Action;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestRequest;
@@ -54,14 +53,12 @@ public class RestGetIndexTemplateV2Action extends BaseRestHandler {
 
     @Override
     public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
-        final String[] names = Strings.splitStringByCommaToArray(request.param("name"));
-
-        final GetIndexTemplateV2Action.Request getRequest = new GetIndexTemplateV2Action.Request(names);
+        final GetIndexTemplateV2Action.Request getRequest = new GetIndexTemplateV2Action.Request(request.param("name"));
 
         getRequest.local(request.paramAsBoolean("local", getRequest.local()));
         getRequest.masterNodeTimeout(request.paramAsTime("master_timeout", getRequest.masterNodeTimeout()));
 
-        final boolean implicitAll = getRequest.names().length == 0;
+        final boolean implicitAll = getRequest.name() == null;
 
         return channel ->
             client.execute(GetIndexTemplateV2Action.INSTANCE, getRequest, new RestToXContentListener<>(channel) {

server/src/test/java/org/elasticsearch/action/admin/indices/template/get/GetIndexTemplateV2RequestTests.java

@@ -32,7 +32,7 @@ public class GetIndexTemplateV2RequestTests extends AbstractWireSerializingTestC
 
     @Override
     protected GetIndexTemplateV2Action.Request createTestInstance() {
-        return new GetIndexTemplateV2Action.Request(generateRandomStringArray(5, 5, false, false));
+        return new GetIndexTemplateV2Action.Request(randomBoolean() ? null : randomAlphaOfLength(4));
     }
 
     @Override