refactor(scheduler): clean JVM shutdown for batch-style entry point

apps/optimizer/schedulerapp/src/main/java/com/linkedin/openhouse/optimizer/scheduler/SchedulerApplication.java

@@ -2,30 +2,62 @@
 
 import com.linkedin.openhouse.optimizer.model.OperationTypeDto;
 import java.util.Map;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.ExitCodeGenerator;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.autoconfigure.domain.EntityScan;
-import org.springframework.context.annotation.Bean;
 import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 
-/** Entry point for the Optimizer Scheduler application. */
+/**
+ * Entry point for the Optimizer Scheduler application.
+ *
+ * <p>Spring Batch–style: implements {@link CommandLineRunner} so the work runs after context
+ * startup, and {@link ExitCodeGenerator} so the JVM exit code reflects batch outcome. {@code
+ * SpringApplication.exit(...)} closes the context (triggers {@code @PreDestroy} hooks, drains the
+ * JPA pool, etc.) so the k8s CronJob pod terminates cleanly with a status reflecting reality.
+ */
+@Slf4j
 @SpringBootApplication
 @EntityScan(basePackages = "com.linkedin.openhouse.optimizer.db")
 @EnableJpaRepositories(basePackages = "com.linkedin.openhouse.optimizer.repository")
-public class SchedulerApplication {
+public class SchedulerApplication implements CommandLineRunner, ExitCodeGenerator {
+
+  private final SchedulerRunner runner;
+  private final Map<OperationTypeDto, BinPacker> binPackers;
+  private int exitCode = 0;
+
+  @Autowired
+  public SchedulerApplication(SchedulerRunner runner, Map<OperationTypeDto, BinPacker> binPackers) {
+    this.runner = runner;
+    this.binPackers = binPackers;
+  }
 
   public static void main(String[] args) {
-    SpringApplication.run(SchedulerApplication.class, args);
+    System.exit(SpringApplication.exit(SpringApplication.run(SchedulerApplication.class, args)));
   }
 
   /**
    * Runs the scheduler once per registered {@link BinPacker} per process invocation. Each call is
-   * scoped to one operation type.
+   * scoped to one operation type. Any thrown exception is logged and surfaces as a non-zero exit
+   * code via {@link #getExitCode()} after the context is shut down cleanly.
    */
-  @Bean
-  public CommandLineRunner run(
-      SchedulerRunner runner, Map<OperationTypeDto, BinPacker> binPackers) {
-    return args -> binPackers.keySet().forEach(runner::schedule);
+  @Override
+  public void run(String... args) {
+    try {
+      log.info("Scheduler starting; operation types: {}", binPackers.keySet());
+      binPackers.keySet().forEach(runner::schedule);
+      log.info("Scheduler completed successfully");
+    } catch (Exception e) {
+      log.error("Scheduler failed", e);
+      exitCode = 1;
+    }
+  }
+
+  @Override
+  public int getExitCode() {
+    return exitCode;
   }
 }

apps/optimizer/schedulerapp/src/main/resources/application.properties

@@ -1,5 +1,6 @@
 spring.application.name=openhouse-optimizer-scheduler
 spring.main.web-application-type=none
+spring.main.banner-mode=off
 spring.datasource.url=${OPTIMIZER_DB_URL:jdbc:h2:mem:schedulerdb;DB_CLOSE_DELAY=-1;MODE=MySQL}
 spring.datasource.username=${OPTIMIZER_DB_USER:sa}
 spring.datasource.password=${OPTIMIZER_DB_PASSWORD:}