Add more logs specifically for the scheduler and close (#40)

* [Add-more-logs] Trying to add more logs specifically for the scheduler and close

* [Add-more-logs] Added logs on notifyDeath silent return

* [Add-more-logs] Added more logs in docker service and removed one

* [Add-more-logs] Spotless...

Author: Alathreon

JShellAPI/src/main/java/org/togetherjava/jshellapi/service/DockerService.java

@@ -131,7 +131,13 @@ public void onNext(Frame object) {
     }
 
     public void killContainerByName(String name) {
-        for (Container container : client.listContainersCmd().withNameFilter(Set.of(name)).exec()) {
+        LOGGER.debug("Fetching container to kill {}.", name);
+        List<Container> containers = client.listContainersCmd().withNameFilter(Set.of(name)).exec();
+        LOGGER.debug("Number of containers to kill: {} for name {}.", containers.size(), name);
+        if (containers.size() != 1) {
+            LOGGER.error("There is more than 1 container for name {}.", name);
+        }
+        for (Container container : containers) {
             client.killContainerCmd(container.getId()).exec();
         }
     }

JShellAPI/src/main/java/org/togetherjava/jshellapi/service/JShellService.java

@@ -206,6 +206,7 @@ public String id() {
 
     @Override
     public void close() {
+        LOGGER.debug("Close called for session {}.", id);
         try {
             dockerService.killContainerByName(containerName());
             try {

JShellAPI/src/main/java/org/togetherjava/jshellapi/service/JShellSessionService.java

@@ -28,6 +28,7 @@ public class JShellSessionService {
     private void initScheduler() {
         scheduler = Executors.newSingleThreadScheduledExecutor();
         scheduler.scheduleAtFixedRate(() -> {
+            LOGGER.info("Scheduler heartbeat: started.");
             jshellSessions.keySet()
                 .stream()
                 .filter(id -> jshellSessions.get(id).isClosed())
@@ -36,6 +37,7 @@ private void initScheduler() {
                 .stream()
                 .filter(id -> jshellSessions.get(id).shouldDie())
                 .toList();
+            LOGGER.info("Scheduler heartbeat: sessions ready to die: {}", toDie);
             for (String id : toDie) {
                 try {
                     deleteSession(id);
@@ -49,8 +51,10 @@ private void initScheduler() {
 
     void notifyDeath(String id) {
         JShellService shellService = jshellSessions.remove(id);
-        if (shellService == null)
+        if (shellService == null) {
+            LOGGER.debug("Notify death on already removed session {}.", id);
             return;
+        }
         if (!shellService.isClosed()) {
             LOGGER.error("JShell Service isn't dead when it should for id {}.", id);
         }