If you need to enable Container Insights for an ECS cluster, by using the AWS CLI, then you can do the following:

aws ecs update-cluster-settings
    --cluster <cluster-name>  
    --settings name=containerInsights,value=enabled 
    --region <aws_region>

Container Insights gives you CPU, memory, disk, and network metrics for your ECS tasks and services in CloudWatch. Without it, you’re flying blind on resource utilization. I enable this on every cluster — the extra CloudWatch costs are minimal compared to the visibility you get.

Note that this only enables the cluster-level setting. Your tasks also need the CloudWatch agent or FireLens configured to actually ship the metrics. For Fargate tasks, Container Insights works automatically once enabled at the cluster level.