fix fabric8io#3865: using just a single builder

doc/MIGRATION-v6.md

@@ -57,7 +57,16 @@ This release introduces kubernetes-client-api and openshift-client-api modules.
 
 If you are directly relying on classes in the -client jars other than DefaultKubernetesClient and DefaultOpenShiftClient, please let us know your usage scenario.  Moving forward we'd like consider all classes in the -client jars internal.
 
-When you rely solely on a compile dependency to the respective -api dependencies you will not be able to use DefaultKubernetesClient nor DefaultOpenShiftClient directly to create your client instances.  You should instead - TBD 
+When you rely solely on a compile dependency to the respective -api dependencies you will not be able to use DefaultKubernetesClient nor DefaultOpenShiftClient directly to create your client instances.  You should instead use KubernetesClientBuilder.  Passing a configuration of HttpClient is instead done through builder methods - withConfig and withHttpClientFactory.  For example:
+
+  ```java
+  KubernetesClient client = new KubernetesClientBuilder().build();
+  ...  
+  ```
+  ```java
+  OpenShiftClient openShiftClient = new new KubernetesClientBuilder().withConfig(new OpenShiftConfigBuilder()...build()).build().adapt(OpenShiftClient.class);
+  ...
+  ```
 
 ### OkHttp HttpClient
 

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/KubernetesClientBuilder.java

@@ -16,10 +16,67 @@
 
 package io.fabric8.kubernetes.client;
 
-public class KubernetesClientBuilder extends BaseKubernetesClientBuilder<KubernetesClientBuilder> {
+import io.fabric8.kubernetes.client.http.HttpClient;
+import io.fabric8.kubernetes.client.utils.Serialization;
+
+import java.io.InputStream;
+import java.lang.reflect.InvocationTargetException;
+
+public class KubernetesClientBuilder {
+
+  private Config config;
+  private HttpClient.Factory factory;
+  private Class<KubernetesClient> clazz;
 
   public KubernetesClientBuilder() {
-    super("io.fabric8.kubernetes.client.DefaultKubernetesClient");
+    // basically the same logic as in KubernetesResourceUtil for finding list types
+    // we're not guarding against a null context class loader
+    String className = "io.fabric8.kubernetes.client.DefaultKubernetesClient";
+    try {
+      clazz = (Class<KubernetesClient>) Thread.currentThread().getContextClassLoader().loadClass(className);
+    } catch (ClassNotFoundException | ClassCastException e) {
+      try {
+        clazz = (Class<KubernetesClient>) KubernetesClient.class.getClassLoader().loadClass(className);
+      } catch (Exception ex) {
+        throw KubernetesClientException.launderThrowable(ex);
+      }
+    }
+  }
+
+  public KubernetesClient build() {
+    if (config == null) {
+      config = new ConfigBuilder().build();
+    }
+    try {
+      if (factory == null) {
+        return clazz.getConstructor(Config.class).newInstance(config);
+      }
+      HttpClient client = factory.createHttpClient(config);
+      return clazz.getConstructor(HttpClient.class, Config.class).newInstance(client, config);
+    } catch (InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException
+        | NoSuchMethodException | SecurityException e) {
+      throw KubernetesClientException.launderThrowable(e);
+    }
+  }
+
+  public KubernetesClientBuilder withConfig(Config config) {
+    this.config = config;
+    return this;
+  }
+
+  public KubernetesClientBuilder withConfig(String config) {
+    this.config = Serialization.unmarshal(config);
+    return this;
+  }
+
+  public KubernetesClientBuilder withConfig(InputStream config) {
+    this.config = Serialization.unmarshal(config);
+    return this;
+  }
+
+  public KubernetesClientBuilder withHttpClientFactory(HttpClient.Factory factory) {
+    this.factory = factory;
+    return this;
   }
 
 }

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/utils/HttpClientUtils.java

@@ -144,6 +144,11 @@ public static String basicCredentials(String username, String password) {
 
   private static final AtomicBoolean WARNED = new AtomicBoolean();
 
+  /**
+   * @deprecated you should not need to call this method directly.  Please create your own HttpClient.Factory
+   * should you need to customize your clients.
+   */
+  @Deprecated
   public static HttpClient createHttpClient(Config config) {
     ServiceLoader<HttpClient.Factory> loader = ServiceLoader.load(HttpClient.Factory.class);
     HttpClient.Factory factory = null;