Fix fabric8io#2316: Cannot load resource from stream without apiVersion

In case of duplicate Kubernetes resources found, when no apiVersion
is provided return first item found instead of null

CHANGELOG.md

@@ -2,12 +2,13 @@
 
 ### 4.10-SNAPSHOT
 #### Bugs
+* Fix #2316: Cannot load resource from stream without apiVersion
 
 #### Improvements
 
 #### Dependency Upgrade
 * Fix #2355: bump jandex from 2.1.3.Final to 2.2.0.Final
-* Fix #2353: bump workflow action-setup-* versions + kubernetes to 1.18.6
+* Fix #2353: bump workflow action-setup- versions + kubernetes to 1.18.6
 
 #### New Features
 * Fix #2287: Add support for V1 and V1Beta1 CustomResourceDefinition

kubernetes-model-generator/kubernetes-model-core/src/main/java/io/fabric8/kubernetes/internal/KubernetesDeserializer.java

@@ -248,16 +248,20 @@ private Class<? extends KubernetesResource> getInternalTypeForName(String key) {
             // If only one class found, return it
             if (possibleResults.size() == 1) {
                 return possibleResults.get(0);
-            }
-
-            // Compare with apiVersions being compared for set of classes found
-            for (Class<? extends KubernetesResource> result : possibleResults) {
+            } else if (possibleResults.size() > 1) {
+              // Compare with apiVersions being compared for set of classes found
+              for (Class<? extends KubernetesResource> result : possibleResults) {
                 String defaultKeyFromClass = getKeyFromClass(result);
                 if (key.equals(defaultKeyFromClass)) {
-                    return result;
+                  return result;
                 }
+              }
+              // Not able to compare with apiVersions, perhaps it was not provided;
+              // return first item found
+              return possibleResults.get(0);
+            } else {
+              return null;
             }
-            return null;
         }
 
         private String getKeyFromClass(Class<? extends KubernetesResource> clazz) {

kubernetes-tests/src/test/java/io/fabric8/kubernetes/client/mock/DeploymentTest.java

@@ -41,6 +41,7 @@
 import io.fabric8.kubernetes.client.server.mock.KubernetesServer;
 
 import io.fabric8.kubernetes.client.utils.Utils;
+import io.fabric8.kubernetes.model.util.Helper;
 import okhttp3.mockwebserver.RecordedRequest;
 import org.junit.Rule;
 import org.junit.jupiter.api.DisplayName;
@@ -772,4 +773,20 @@ private DeploymentBuilder getDeploymentBuilder() {
       .endSpec();
   }
 
+  @Test
+  void testDeploymentLoadWithoutApiVersion() {
+    // Given
+    KubernetesClient client = server.getClient();
+
+    // When
+    List<HasMetadata> list = client.load(getClass().getResourceAsStream("/valid-deployment-without-apiversion.json")).get();
+    Deployment deployment = (Deployment) list.get(0);
+
+    // Then
+    assertNotNull(deployment);
+    assertEquals("test", deployment.getMetadata().getName());
+    assertEquals(1, deployment.getSpec().getReplicas());
+    assertEquals(1, deployment.getSpec().getTemplate().getSpec().getContainers().size());
+  }
+
 }

kubernetes-tests/src/test/resources/valid-deployment-without-apiversion.json

@@ -0,0 +1,39 @@
+{
+  "kind": "Deployment",
+  "metadata": {
+    "name": "test",
+    "labels": {
+      "app": "test"
+    }
+  },
+  "spec": {
+    "selector": {
+      "matchLabels": {
+        "app": "test"
+      }
+    },
+    "replicas": 1,
+    "template": {
+      "metadata": {
+        "labels": {
+          "app": "test"
+        }
+      },
+      "spec": {
+        "containers": [
+          {
+            "name": "test",
+            "image": "busybox:latest",
+            "command": [
+              "/bin/sh",
+              "-c"
+            ],
+            "args": [
+              "sleep 60"
+            ]
+          }
+        ]
+      }
+    }
+  }
+}