Merge pull request #520 from roldevg/multiple_kubeconfigs

Added support for KUBECONFIG environment variable with multiple paths.

Author: k8s-ci-robot

util/src/main/java/io/kubernetes/client/util/ClientBuilder.java

@@ -104,10 +104,14 @@ public static ClientBuilder standard(boolean persistConfig) throws IOException {
   }
 
   private static File findConfigFromEnv() {
-    String kubeConfigPath = System.getenv(ENV_KUBECONFIG);
+    final KubeConfigEnvParser kubeConfigEnvParser = new KubeConfigEnvParser();
+
+    final String kubeConfigPath =
+        kubeConfigEnvParser.parseKubeConfigPath(System.getenv(ENV_KUBECONFIG));
     if (kubeConfigPath == null) {
       return null;
     }
+
     final File kubeConfig = new File(kubeConfigPath);
     if (kubeConfig.exists()) {
       return kubeConfig;
@@ -117,6 +121,24 @@ private static File findConfigFromEnv() {
     }
   }
 
+  private static class KubeConfigEnvParser {
+    private String parseKubeConfigPath(String kubeConfigEnv) {
+      if (kubeConfigEnv == null) {
+        return null;
+      }
+
+      final String[] filePaths = kubeConfigEnv.split(File.pathSeparator);
+      final String kubeConfigPath = filePaths[0];
+      if (filePaths.length > 1) {
+        log.warn(
+            "Found multiple kubeconfigs files, $KUBECONFIG: " + kubeConfigEnv + " using first: {}",
+            kubeConfigPath);
+      }
+
+      return kubeConfigPath;
+    }
+  }
+
   private static File findHomeDir() {
     final String envHome = System.getenv(ENV_HOME);
     if (envHome != null && envHome.length() > 0) {

util/src/test/java/io/kubernetes/client/util/ClientBuilderTest.java

@@ -21,6 +21,7 @@
 import com.google.common.io.Resources;
 import io.kubernetes.client.ApiClient;
 import io.kubernetes.client.util.credentials.Authentication;
+import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -76,6 +77,14 @@ public void testDefaultClientReadsKubeConfig() throws Exception {
     assertEquals("http://kubeconfig.dir.com", client.getBasePath());
   }
 
+  @Test
+  public void testDefaultClientReadsKubeConfigMultiple() throws Exception {
+    final String kubeConfigEnv = KUBECONFIG_FILE_PATH + File.pathSeparator + "/non-existent";
+    environmentVariables.set("KUBECONFIG", kubeConfigEnv);
+    final ApiClient client = ClientBuilder.defaultClient();
+    assertEquals("http://kubeconfig.dir.com", client.getBasePath());
+  }
+
   @Test
   public void testKubeconfigPreferredOverHomeDir() throws Exception {
     environmentVariables.set("HOME", HOME_PATH);