We have a Docker container(Spring Boot) that runs in an ECS cluster. We run it without Elastic Load Balancing.
We want to update the service without downtime, so when the new task is up and healthy, the old task stops. We have been trying to add a health check on the task definition, however it refuses to work. I have tried these basic healthcheck commands.
[ "CMD-SHELL","exit 0" ]
[ "CMD-SHELL","exit 1" ]
I would expect the former to result in a task with a HEALTHY health status, and the latter to fail the health checks..
In both cases, the new task starts fine, with an UNKNOWN health status.
Has this anything to do with us not using an ELB? The documentation is not very good, and my Google searches have not returned anything useful.
Best Answer
The answer by raja and edite by Andrew are slightly off for ECS/FARGATE. It's without the brackets and without the quotes:
That is the correct format if entering Health check information inside Task Definitions of ECS.
VALID DOCUMENTATION https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#container_definition_healthcheck
NOT VALID DOCUMENTATION for ECS/FARGATE https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_HealthCheck.html