Return a default APIClient if we run into an exception

Author: Ryan Baxter

spring/src/main/java/io/kubernetes/client/spring/extended/controller/config/KubernetesInformerAutoConfiguration.java

@@ -16,6 +16,9 @@
 import io.kubernetes.client.openapi.ApiClient;
 import io.kubernetes.client.spring.extended.controller.KubernetesInformerFactoryProcessor;
 import io.kubernetes.client.util.ClientBuilder;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
 import java.io.IOException;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.context.annotation.Bean;
@@ -25,10 +28,32 @@
 @ConditionalOnKubernetesInformerEnabled
 public class KubernetesInformerAutoConfiguration {
 
+  private static final Log LOG = LogFactory.getLog(KubernetesInformerAutoConfiguration.class);
+
   @Bean
   @ConditionalOnMissingBean
   public ApiClient defaultApiClient() throws IOException {
-    return ClientBuilder.defaultClient();
+    try {
+      // Assume we are running in a cluster
+      ApiClient apiClient = ClientBuilder.cluster().build();
+      LOG.info("Created API client in the cluster.");
+      return apiClient;
+    }
+    catch (Exception e) {
+      LOG.info("Could not create the Kubernetes ApiClient in a cluster environment, because : ", e);
+      LOG.info("Trying to use a \"standard\" configuration to create the Kubernetes ApiClient");
+      try {
+        ApiClient apiClient = ClientBuilder.defaultClient();
+        LOG.info("Created standard API client. Unless $KUBECONFIG or $HOME/.kube/config is defined, "
+                + "this client will try to connect to localhost:8080");
+        return apiClient;
+      }
+      catch (Exception e1) {
+        LOG.warn("Could not create a Kubernetes ApiClient from either a cluster or standard environment. "
+                + "Will return one that always connects to localhost:8080", e1);
+        return new ClientBuilder().build();
+      }
+    }
   }
 
   @Bean