Stuck CloudFormation Stack
The CloudFormation stack update or creation can get stuck in a
*_IN_PROGRESS state for a very long time, like more than an hour. This happens when you deploy an ECS service that fails to stabilize. Usually, this is an error with the Docker container failing to start up successfully.
There can be many reasons for this. Here are some examples:
- Bug in the startup script in the Dockerfile.
- There are no container instances available to place the docker ECS task. If you’re using ECS EC2, you might have enough EC2 Container instances. Perhaps your max size limit is preventing the addition of more EC2 instances.
- You have a rails app, and it is failing to connect to the database upon startup, maybe due to a security group setting.
To resolve this, you can:
- cancel the current deploy
- fix the underlying issue
- deploy again
If an ECS deployment does not finish within 10 minutes because the ECS service is not stabilizing, it is usually due to one of the reasons above. In these cases, it is safe to cancel and try again.
To cancel a current deployment, run:
This is the same as canceling the stack update in the CloudFormation console.