Use v3 version when v2 unavailable (#1359)

* make compatibilityChecker robust if v2 api is disabled

Co-authored-by: Georg Lokowandt <georg.lokowandt@sap.com>

Author: Kehrlann

cloudfoundry-client-reactor/src/main/java/org/cloudfoundry/reactor/client/CloudFoundryClientCompatibilityChecker.java

@@ -20,27 +20,30 @@
 
 import com.github.zafarkhaja.semver.Version;
 import org.cloudfoundry.client.CloudFoundryClient;
+import org.cloudfoundry.client.GetRootRequest;
+import org.cloudfoundry.client.Root;
 import org.cloudfoundry.client.v2.info.GetInfoRequest;
 import org.cloudfoundry.client.v2.info.Info;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import reactor.core.publisher.Mono;
+import reactor.util.function.Tuple2;
 
 final class CloudFoundryClientCompatibilityChecker {
 
     private final Logger logger = LoggerFactory.getLogger("cloudfoundry-client.compatibility");
 
     private final Info info;
+    private final Root root;
 
-    CloudFoundryClientCompatibilityChecker(Info info) {
+    CloudFoundryClientCompatibilityChecker(Info info, Root root) {
         this.info = info;
+        this.root = root;
     }
 
     void check() {
-        this.info
-                .get(GetInfoRequest.builder().build())
-                .map(response -> Version.valueOf(response.getApiVersion()))
-                .zipWith(Mono.just(Version.valueOf(CloudFoundryClient.SUPPORTED_API_VERSION)))
+        Mono<Tuple2<Version, Version>> v2 = checkV2();
+        v2.switchIfEmpty(checkV3())
                 .subscribe(
                         consumer(
                                 (server, supported) ->
@@ -51,11 +54,41 @@ void check() {
                                         t));
     }
 
+    private Mono<Tuple2<Version, Version>> checkV2() {
+        return this.info
+                .get(GetInfoRequest.builder().build())
+                .flatMap(
+                        response -> {
+                            String version = response.getApiVersion();
+                            if (version == null || version.isEmpty()) {
+                                if ("CF API v2 is disabled".equals(response.getSupport())) {
+                                    this.logger.warn(
+                                            "calling v2 info endpoint but CF API v2 is disabled",
+                                            response);
+                                }
+                                return Mono.empty();
+                            } else {
+                                return Mono.just(Version.valueOf(version));
+                            }
+                        })
+                .zipWith(Mono.just(Version.valueOf(CloudFoundryClient.SUPPORTED_API_VERSION)));
+    }
+
+    private Mono<Tuple2<Version, Version>> checkV3() {
+        return this.root
+                .get(GetRootRequest.builder().build())
+                .map(
+                        response -> {
+                            String versionV3 = response.getApiVersionV3();
+                            return Version.valueOf(versionV3);
+                        })
+                .zipWith(Mono.just(Version.valueOf(CloudFoundryClient.SUPPORTED_API_VERSION_V3)));
+    }
+
     private static void logCompatibility(Version server, Version supported, Logger logger) {
         String message =
                 "Client supports API version {} and is connected to server with API version {}."
                         + " Things may not work as expected.";
-
         if (server.greaterThan(supported)) {
             logger.info(message, supported, server);
         } else if (server.lessThan(supported)) {

cloudfoundry-client-reactor/src/main/java/org/cloudfoundry/reactor/client/ReactorRoot.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2013-2021 the original author or 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 org.cloudfoundry.reactor.client;
+
+import java.util.Map;
+import org.cloudfoundry.client.GetRootRequest;
+import org.cloudfoundry.client.GetRootResponse;
+import org.cloudfoundry.client.Root;
+import org.cloudfoundry.reactor.ConnectionContext;
+import org.cloudfoundry.reactor.TokenProvider;
+import org.cloudfoundry.reactor.client.v3.AbstractClientV3Operations;
+import reactor.core.publisher.Mono;
+
+/**
+ * The Reactor-based implementation of {@link Root}
+ */
+public class ReactorRoot extends AbstractClientV3Operations implements Root {
+
+    /**
+     * Creates an instance
+     *
+     * @param connectionContext the {@link ConnectionContext} to use when communicating with the server
+     * @param root              the root URI of the server. Typically something like {@code https://api.run.pivotal.io}.
+     * @param tokenProvider     the {@link TokenProvider} to use when communicating with the server
+     * @param requestTags       map with custom http headers which will be added to web request
+     */
+    public ReactorRoot(
+            ConnectionContext connectionContext,
+            Mono<String> root,
+            TokenProvider tokenProvider,
+            Map<String, String> requestTags) {
+        super(connectionContext, root, tokenProvider, requestTags);
+    }
+
+    @Override
+    public Mono<GetRootResponse> get(GetRootRequest request) {
+        return get(request, GetRootResponse.class, builder -> builder.pathSegment("")).checkpoint();
+    }
+}

cloudfoundry-client-reactor/src/main/java/org/cloudfoundry/reactor/client/_ReactorCloudFoundryClient.java

@@ -18,6 +18,7 @@
 
 import jakarta.annotation.PostConstruct;
 import org.cloudfoundry.client.CloudFoundryClient;
+import org.cloudfoundry.client.Root;
 import org.cloudfoundry.client.v2.applications.ApplicationsV2;
 import org.cloudfoundry.client.v2.applicationusageevents.ApplicationUsageEvents;
 import org.cloudfoundry.client.v2.blobstores.Blobstores;
@@ -205,7 +206,7 @@ public Builds builds() {
 
     @PostConstruct
     public void checkCompatibility() {
-        new CloudFoundryClientCompatibilityChecker(info()).check();
+        new CloudFoundryClientCompatibilityChecker(info(), rootEndpoint()).check();
     }
 
     @Override
@@ -257,6 +258,13 @@ public Info info() {
         return new ReactorInfo(getConnectionContext(), getRootV2(), getTokenProvider(), getRequestTags());
     }
 
+    @Override
+    @Value.Derived
+    public Root rootEndpoint() {
+        Mono<String> root = getConnectionContext().getRootProvider().getRoot(getConnectionContext());
+        return new ReactorRoot(getConnectionContext(), root, getTokenProvider(), getRequestTags());
+    }
+
     @Override
     @Value.Derived
     public IsolationSegments isolationSegments() {

cloudfoundry-client/src/main/java/org/cloudfoundry/client/CloudFoundryClient.java

@@ -85,6 +85,8 @@ public interface CloudFoundryClient {
      */
     String SUPPORTED_API_VERSION = "2.272.0";
 
+    String SUPPORTED_API_VERSION_V3 = "3.216.0";
+
     /**
      * Main entry point to the Cloud Foundry Application Usage Events Client API
      */
@@ -170,6 +172,11 @@ public interface CloudFoundryClient {
      */
     Info info();
 
+    /**
+     * Main entry point to the Cloud Foundry root endpoint
+     */
+    Root rootEndpoint();
+
     /**
      * Main entry point to the Cloud Foundry Isolation Segments API
      */

cloudfoundry-client/src/main/java/org/cloudfoundry/client/Root.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2013-2026 the original author or 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 org.cloudfoundry.client;
+
+import reactor.core.publisher.Mono;
+
+/**
+ * Main entry point to the Cloud Foundry RootV3 Client API
+ */
+public interface Root {
+
+    /**
+     * Makes the <a href="https://v3-apidocs.cloudfoundry.org/index.html#root">Get root</a> request
+     *
+     * @param request the Get Root request
+     * @return the response from the Get Root request
+     */
+    Mono<GetRootResponse> get(GetRootRequest request);
+}

cloudfoundry-client/src/main/java/org/cloudfoundry/client/_GetRootRequest.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2013-2021 the original author or 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 org.cloudfoundry.client;
+
+import org.immutables.value.Value;
+
+/**
+ * The request payload for the Get root "/" operation
+ */
+@Value.Immutable
+abstract class _GetRootRequest {
+
+}