Fixes #983: log usage of unstable api

kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/base/OperationSupport.java

@@ -20,6 +20,7 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 
+import io.fabric8.kubernetes.client.internal.VersionUsageUtils;
 import io.fabric8.kubernetes.client.utils.Serialization;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
@@ -373,6 +374,7 @@ protected <T> T handleResponse(OkHttpClient client, Request.Builder requestBuild
    * @throws IOException
    */
   protected <T> T handleResponse(OkHttpClient client, Request.Builder requestBuilder, Class<T> type, Map<String, String> parameters) throws ExecutionException, InterruptedException, KubernetesClientException, IOException {
+    VersionUsageUtils.log(this.resourceT, this.apiVersion);
     Request request = requestBuilder.build();
     Response response = client.newCall(request).execute();
     try (ResponseBody body = response.body()) {

kubernetes-client/src/main/java/io/fabric8/kubernetes/client/internal/VersionUsageUtils.java

@@ -0,0 +1,43 @@
+package io.fabric8.kubernetes.client.internal;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Utility class to monitor alhpa/beta version usage and log.
+ */
+public final class VersionUsageUtils {
+
+  private static final Logger LOG = LoggerFactory.getLogger(VersionUsageUtils.class);
+
+  private static ConcurrentHashMap<String, Boolean> UNSTABLE_TYPES = new ConcurrentHashMap<>();
+
+  private static final boolean LOG_EACH_USAGE = false;
+
+  private VersionUsageUtils() {
+  }
+
+  public static void log(String type, String version) {
+    if (type == null || version == null) {
+      return;
+    }
+
+    if (isUnstable(version)) {
+      if (LOG_EACH_USAGE || UNSTABLE_TYPES.putIfAbsent(type + "-" + version, true) == null) {
+        alert(type, version);
+      }
+    }
+  }
+
+  private static boolean isUnstable(String version) {
+    String lowerCaseVersion = version.toLowerCase();
+    return lowerCaseVersion.contains("beta") || lowerCaseVersion.contains("alpha");
+  }
+
+  private static void alert(String type, String version) {
+    LOG.warn("The client is using resource type '{}' with unstable version '{}'", type, version);
+  }
+
+}