Why do i need an eval around a subshell script?

Question

I'm using the ECR credentials task, and have written a small script to push a docker image to ecr.  for some reason, the below command is not successful unless i wrap it in an eval.

$(aws ecr get-login --no-include-email).

eval $(aws ecr get-login --no-include-email)  --- works

The examples i read for ecr did not include this.  I'm ok with it if that's how it has to work, just not entirely clear why.

Steffen Opel [Utoolity] · Accepted Answer

Hi Jason, welcome to the community!

I'm not exactly a shell expert myself, so please allow me to postpone looking into your actual question in favor of an upfront clarification:

When you say you are 'using the ECR credentials task', do you in fact mean our Amazon ECR Credentials Variables task, or just a regular Bamboo Script task to get the credentials solely via the AWS CLI as outlined in your question?

Cheers,
Steffen