How to diagnose ECS Fargate task failing to start?

Question

I\'m trying to launch/run a Dockerfile on AWS using their ECS service. I can run my docker image locally just fine, but it\'s failing on the Fargate launch type. I\'ve uploaded

Answer 1

As Abhinav says, the message isn't very descriptive (and using the CLI aws ecs describe-tasks doesn't add anything more). The only possibility is to log into the host EC2 instance and read the logs there, or send those logs to CloudWatch https://docs.aws.amazon.com/AmazonECS/latest/developerguide/using_cloudwatch_logs.html#cwlogs_user_data

The mostly likely cause (in ECS) is that the cluster doesn't have enough resources to launch the new task. You can sometimes work out the cause from the Metrics tab, or since mid-2019 (depending on your region I guess) you can enable "CloudWatch Container Insights" from ECS Account Settings to get more detailed information about memory and CPU reservations.