Open1
ECS Exec

1つのタスクのみの場合はこれでOK
cluster_name=hoge
service_name=hoge
container_name=app
ARN=$(aws ecs list-tasks --cluster ${cluster_name} --query "taskArns[]" --service-name ${service_name} --output text)
aws ecs execute-command --cluster ${cluster_name} \
--task $ARN \
--container ${container_name}\
--interactive \
--command "/bin/bash"