refactor: move identity generation to configuration

Author: metacosm

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/LeaderElectionManager.java

@@ -1,6 +1,5 @@
 package io.javaoperatorsdk.operator;
 
-import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 
 import org.slf4j.Logger;
@@ -16,7 +15,7 @@
 import io.javaoperatorsdk.operator.api.config.ConfigurationServiceProvider;
 import io.javaoperatorsdk.operator.api.config.LeaderElectionConfiguration;
 
-public class LeaderElectionManager {
+class LeaderElectionManager {
 
   private static final Logger log = LoggerFactory.getLogger(LeaderElectionManager.class);
 
@@ -30,25 +29,24 @@ public LeaderElectionManager(ControllerManager controllerManager) {
   }
 
   public void init(LeaderElectionConfiguration config, KubernetesClient client) {
-    this.identity = identity(config);
+    this.identity = config.getIdentity();
     Lock lock = new LeaseLock(config.getLeaseNamespace(), config.getLeaseName(), identity);
     // releaseOnCancel is not used in the underlying implementation
     leaderElector = new LeaderElectorBuilder(client,
         ConfigurationServiceProvider.instance().getExecutorService())
-        .withConfig(
-            new LeaderElectionConfig(lock, config.getLeaseDuration(), config.getRenewDeadline(),
-                config.getRetryPeriod(), leaderCallbacks(), true, config.getLeaseName()))
-        .build();
+            .withConfig(
+                new LeaderElectionConfig(lock, config.getLeaseDuration(), config.getRenewDeadline(),
+                    config.getRetryPeriod(), leaderCallbacks(), true, config.getLeaseName()))
+            .build();
   }
 
   public boolean isLeaderElectionOn() {
     return leaderElector != null;
   }
 
   private LeaderCallbacks leaderCallbacks() {
-    return new LeaderCallbacks(this::startLeading, this::stopLeading, leader -> {
-      log.info("New leader with identity: {}", leader);
-    });
+    return new LeaderCallbacks(this::startLeading, this::stopLeading,
+        leader -> log.info("New leader with identity: {}", leader));
   }
 
   private void startLeading() {
@@ -63,14 +61,6 @@ private void stopLeading() {
     System.exit(1);
   }
 
-  private String identity(LeaderElectionConfiguration config) {
-    String id = config.getIdentity().orElse(System.getenv("HOSTNAME"));
-    if (id == null || id.isBlank()) {
-      id = UUID.randomUUID().toString();
-    }
-    return id;
-  }
-
   public void start() {
     if (isLeaderElectionOn()) {
       leaderElectionFuture = leaderElector.start();

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/LeaderElectionConfiguration.java

@@ -1,7 +1,9 @@
 package io.javaoperatorsdk.operator.api.config;
 
 import java.time.Duration;
-import java.util.Optional;
+import java.util.UUID;
+
+import io.fabric8.zjsonpatch.internal.guava.Strings;
 
 public class LeaderElectionConfiguration {
 
@@ -11,7 +13,7 @@ public class LeaderElectionConfiguration {
 
   private final String leaseName;
   private final String leaseNamespace;
-  private final String identity;
+  private String identity;
 
   private final Duration leaseDuration;
   private final Duration renewDeadline;
@@ -70,7 +72,18 @@ public Duration getRetryPeriod() {
     return retryPeriod;
   }
 
-  public Optional<String> getIdentity() {
-    return Optional.ofNullable(identity);
+  public String getIdentity() {
+    if (identity == null) {
+      identity = System.getenv("HOSTNAME");
+      if (Strings.isNullOrEmpty(identity)) {
+        identity = UUID.randomUUID().toString();
+      } else {
+        identity = identity.trim();
+        if (identity.isBlank()) {
+          identity = UUID.randomUUID().toString();
+        }
+      }
+    }
+    return identity;
   }
 }