How do I stop an ECS deployment that does not use CodeDeploy? The ECS deployment is stuck in "In progress".

If you are not using Circuit Breaker or CloudWatch Alarms to roll back your Deployment on failed ECS Tasks during the deployment you have to deploy a new Deployment with new Task Definition which will pass health checks, or revert the Task Definition version to the last known working version.

According to the https://aws.amazon.com/blogs/containers/automate-rollbacks-for-amazon-ecs-rolling-deployments-with-cloudwatch-alarms/ blog post: "By default, when the tasks in a service are unable to reach a healthy state, the scheduler applies the service throttling logic to retry the deployments and it required manual intervention to cancel the deployments after a certain number of failed attempts."

ECS Deployment "stuck" in the "In progress" state is expected behavior.