add basic rootNode query

src/main/java/io/cryostat/graphql/GraphQL.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright The Cryostat Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.cryostat.graphql;
+
+import java.net.URI;
+
+import jakarta.annotation.security.RolesAllowed;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.POST;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.core.Response;
+import org.jboss.resteasy.reactive.RestResponse;
+
+@Path("")
+public class GraphQL {
+
+    @GET
+    @Path("/api/v2.2/graphql")
+    @RolesAllowed("write")
+    public Response redirectGet() throws Exception {
+        return Response.status(RestResponse.Status.PERMANENT_REDIRECT)
+                .location(URI.create("/api/v3/graphql"))
+                .build();
+    }
+
+    @POST
+    @Path("/api/v2.2/graphql")
+    @RolesAllowed("write")
+    public Response redirectPost() throws Exception {
+        return Response.status(RestResponse.Status.PERMANENT_REDIRECT)
+                .location(URI.create("/api/v3/graphql"))
+                .build();
+    }
+}

src/main/java/io/cryostat/graphql/RootNode.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright The Cryostat Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.cryostat.graphql;
+
+import io.cryostat.discovery.DiscoveryNode;
+
+import org.eclipse.microprofile.graphql.Description;
+import org.eclipse.microprofile.graphql.GraphQLApi;
+import org.eclipse.microprofile.graphql.Query;
+
+@GraphQLApi
+public class RootNode {
+
+    @Query("rootNode")
+    @Description("Get the root target discovery node")
+    public DiscoveryNode getRootNode() {
+        return DiscoveryNode.getUniverse();
+    }
+}

src/main/resources/application.properties

@@ -41,6 +41,9 @@ quarkus.smallrye-openapi.info-contact-url=https://cryostat.io
 quarkus.smallrye-openapi.info-license-name=Apache 2.0
 quarkus.smallrye-openapi.info-license-url=https://github.com/cryostatio/cryostat3/blob/main/LICENSE
 
+quarkus.smallrye-graphql.root-path=/api/v3/graphql
+quarkus.smallrye-graphql.http.get.enabled=true
+
 quarkus.http.access-log.enabled=true
 quarkus.log.category."io.quarkus.http.access-log".level=DEBUG
 quarkus.http.enable-compression=true