Cancelling an Amazon ECS service deployment typically refers to the process of systematically removing the service and its associated infrastructure from your AWS environment. This comprehensive cleanup ensures that resources are de-provisioned, costs are minimized, and your AWS account remains organized.
The process involves several key steps, generally performed in reverse order of how the resources were created, to avoid orphaned components.
Understanding ECS Deployment Cancellation
When you "cancel" an ECS service deployment, you're essentially decommissioning it. This involves stopping tasks, deleting the service, removing container images, and tearing down the infrastructure that provisioned it, especially if managed by tools like AWS CloudFormation. It's crucial to follow these steps carefully to ensure all related resources are properly removed.
Step-by-Step Guide to Decommission an ECS Service Deployment
To effectively cancel and remove an ECS service deployment, follow these sequential steps:
1. Delete Container Images from Amazon Elastic Container Registry (ECR)
Before dismantling the running service, it's good practice to remove the container images that powered it. This prevents storage charges for unused images.
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Navigate to ECR: Sign into your AWS Management Console and go to Amazon ECR.
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Select Repository: Locate and select the specific Repository that contains the container images used by your ECS service.
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Delete Images/Repository: You can select individual images to delete or, if the entire repository is no longer needed, select the repository and click Delete. Confirm the action when prompted.
- Practical Insight: Deleting an ECR repository is permanent. Ensure no other services depend on these images before proceeding.
2. Stop the Amazon ECS Service and Deregister Tasks
The ECS service is responsible for maintaining the desired count of your tasks. Deleting the service will initiate the stopping and deregistering of its associated tasks.
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Access ECS: Sign into your AWS Account and navigate to Amazon ECS.
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Select Cluster: Choose the Cluster where your service is deployed.
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Find Service: Go to the Services tab and select the specific service you wish to cancel.
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Delete Service: Click Delete to remove the service. Alternatively, you can first update the service's desired task count to
0to gracefully scale down, and then delete the service once all tasks have stopped.- Practical Insight: Deleting the service directly is often the quickest way to initiate the teardown.
3. Stop Any Remaining AWS Fargate Tasks (if applicable)
While deleting the service should stop its associated tasks, sometimes individual tasks might remain in a running state or have been launched independently. It's good to verify and manually stop any persistent tasks.
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View Tasks: Within your Amazon ECS Cluster view, navigate to the Tasks tab.
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Identify and Stop: Look for any running tasks that belong to the deployment you are cancelling. Select them and click Stop.
- Practical Insight: Regularly check the "Desired Status" of your tasks to ensure they transition to "Stopped" after taking action.
4. Delete the CloudFormation Stack (if provisioned via CloudFormation)
If your ECS service, cluster, task definitions, and other supporting infrastructure (like load balancers, security groups, etc.) were created using AWS CloudFormation, deleting the stack is the most efficient and recommended way to remove all these resources in one go.
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Go to CloudFormation: Sign into your AWS Management Console and navigate to CloudFormation.
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Select Stack: Identify and select the CloudFormation Stack that deployed your ECS service. This stack typically has a name descriptive of your application (e.g., "MyWebApp-ECS-Stack").
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Delete Stack: Click Delete. Confirm the deletion when prompted.
- Practical Insight: CloudFormation handles dependencies, deleting resources in the correct order. Monitor the "Events" tab of the stack for any errors during deletion, which might require manual intervention for specific resources (e.g., non-empty S3 buckets).
5. Clean Up Other Associated Resources
Depending on how your deployment was set up, there might be other resources that need manual review and deletion, especially if they were not managed by CloudFormation.
- CloudWatch Log Groups: Check Amazon CloudWatch for log groups created for your ECS tasks and delete them if no longer needed.
- Load Balancers & Target Groups: Verify that any Elastic Load Balancers and Target Groups associated with your service have been removed.
- IAM Roles & Policies: Review IAM roles and policies specifically created for your ECS tasks and services; delete them if they are no longer in use.
- VPC Components: Inspect VPC components like custom security groups or subnets if they were created specifically for this deployment and are now redundant.
Systematically cancelling an ECS service deployment by following these steps ensures a clean removal of all associated resources, preventing unnecessary costs and maintaining an organized AWS environment.
