Update the container of a service in Amazon ECS

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Not sure if this is considered as abandoned question – stumbled upon this while troubleshooting my issue and now adding my solution now that it’s resolved.

To update service with new container, you need to:

  1. upload new container to repository;
  2. trigger task definition update;
  3. trigger container update;
  4. important: make sure service rules allow launching new version of the task.

If service task is not updated to latest version, check “events” tab for errors. For example, maybe ECS was not able to start new version of your service: you only have one ec2 instance in the cluster and the application port is already used on the host. In this case, set “min health/max health” limits to “0%, 100%” – this way, ECS will choose to kill old container before deploying new one. This is also happening over a course of few minutes – don’t rush if you don’t see immediate feedback.

Below is an example deployment script to update container in a pre-configured cluster and service. Note there is no need to specify versions if you just mean “use latest from the family”.

awsRegion=us-east-1
containerName=..
containerRepository=..
taskDefinitionFile=...
taskDefinitionName=...
serviceName=...


echo 'build docker image...'
docker build -t $containerName .

echo 'upload docker image...'
docker tag $containerName:latest $containerRepository:$containerName
docker push $containerRepository:$containerName

echo 'update task definition...'
aws ecs register-task-definition --cli-input-json file://$taskDefinitionFile --region $awsRegion > /dev/null

echo 'update our service with that last task..'
aws ecs update-service --service $serviceName --task-definition $taskDefinitionName --region $awsRegion  > /dev/null

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