CHE-2927: Add logs for active containers checked by DockerContainerCl…

…eaner. (#2950)

Signed-off-by: Aleksandr Andrienko <aandrienko@codenvy.com>

plugins/plugin-docker/che-plugin-docker-machine/src/main/java/org/eclipse/che/plugin/docker/machine/cleaner/DockerContainerCleaner.java

@@ -23,6 +23,8 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
@@ -31,7 +33,7 @@
 import static org.eclipse.che.plugin.docker.machine.DockerContainerNameGenerator.ContainerNameInfo;
 
 /**
- * Job for periodically clean up inactive docker containers
+ * Job for periodically clean up inactive docker containers and log list active containers.
  *
  * @author Alexander Andrienko
  */
@@ -59,19 +61,22 @@ public DockerContainerCleaner(CheEnvironmentEngine environmentEngine,
                   unit = TimeUnit.MINUTES)
     @Override
     public void run() {
+        List<String> activeContainers = new ArrayList<>();
         try {
             for (ContainerListEntry container : dockerConnector.listContainers()) {
-                Optional<ContainerNameInfo> optional = nameGenerator.parse(container.getNames()[0]);
+                String containerName = container.getNames()[0];
+                Optional<ContainerNameInfo> optional = nameGenerator.parse(containerName);
                 if (optional.isPresent()) {
                     try {
                         // container is orphaned if not found exception is thrown
                         environmentEngine.getMachine(optional.get().getWorkspaceId(),
                                                      optional.get().getMachineId());
-
+                        activeContainers.add(containerName);
                     } catch (NotFoundException e) {
                         cleanUp(container);
                     } catch (Exception e) {
-                        LOG.error("Failed to clean up inactive container. " + e.getLocalizedMessage(), e);
+                        LOG.error(format("Failed to check activity for container with name '%s'. Cause: %s",
+                                         containerName, e.getLocalizedMessage()), e);
                     }
                 }
             }
@@ -80,6 +85,7 @@ public void run() {
         } catch (Exception e) {
             LOG.error("Failed to clean up inactive containers", e);
         }
+        LOG.info("List containers registered in the api: " + activeContainers);
     }
 
     private void cleanUp(ContainerListEntry container) {