}
  }

  private static class NoOpService extends AbstractService {
    boolean running = false;

    @Override
    protected void doStart() {
      assertFalse(running);
      running = true;
      notifyStarted();
    }

    @Override
    protected void doStop() {
      assertTrue(running);
      running = false;
      notifyStopped();
    }
  }

And the **container** itself (in contrast to the **container image**) is the actual running instance of the image, comparable to a **process**. In fact, a container is running only when it has a **process running** (and normally it's only a single process). The container stops when there's no process running in it.

## Container Images

        }
      };
  private static final ListenerCallQueue.Event<Listener> RUNNING_EVENT =
      new ListenerCallQueue.Event<Listener>() {
        @Override
        public void call(Listener listener) {
          listener.running();
        }

        @Override
        public String toString() {
          return "running()";
        }
      };

  enum WorkerRunningState {
    /** Runnable is not running and not queued for execution */
    IDLE,
    /** Runnable is not running, but is being queued for execution */
    QUEUING,
    /** runnable has been submitted but has not yet begun execution */
    QUEUED,
    RUNNING,
  }

  /** Underlying executor that all submitted Runnable objects are run on. */

    steps:
      - name: Stop old running containers (if any)
        shell: bash
        run: |
          running_containers=$(docker ps -q) && \
          if [[ $running_containers == "" ]]; then
            echo "No running containers";
          else
            echo "Running container(s) found" && \
            docker stop $running_containers;
          fi
          docker container prune -f

        pyver: ['3.10']
    steps:
      - name: Stop old running containers (if any)
        shell: bash
        run: |
          running_containers=$(docker ps -q) && \
          if [[ $running_containers == "" ]]; then
            echo "No running containers";
          else
            echo "Running container(s) found" && \
            docker stop $running_containers;
          fi
          docker container prune -f

    assertLessThan(NEW, STARTING);
    assertLessThan(NEW, TERMINATED);

    assertLessThan(STARTING, RUNNING);
    assertLessThan(STARTING, STOPPING);
    assertLessThan(STARTING, FAILED);

    assertLessThan(RUNNING, STOPPING);
    assertLessThan(RUNNING, FAILED);

    assertLessThan(STOPPING, FAILED);
    assertLessThan(STOPPING, TERMINATED);
  }

Let's check back those deployment concepts from before:

* Security - HTTPS
* Running on startup
* Restarts
* **Replication (the number of processes running)**
* Memory
* Previous steps before starting

Up to this point, with all the tutorials in the docs, you have probably been running a **server program** like Uvicorn, running a **single process**.

* The process can be **terminated** (or "killed") by you, or by the operating system. At that point, it stops running/being executed, and it can **no longer do things**.
* Each application that you have running on your computer has some process behind it, each running program, each window, etc. And there are normally many processes running **at the same time** while a computer is on.

    assertLessThan(NEW, STARTING);
    assertLessThan(NEW, TERMINATED);

    assertLessThan(STARTING, RUNNING);
    assertLessThan(STARTING, STOPPING);
    assertLessThan(STARTING, FAILED);

    assertLessThan(RUNNING, STOPPING);
    assertLessThan(RUNNING, FAILED);

    assertLessThan(STOPPING, FAILED);
    assertLessThan(STOPPING, TERMINATED);
  }