How can I access my S3 bucket from a container without having my AWS credentials in the code?
My code also auto-deploy, so having it as an Env-variable is also no good (the deployment script is in the repository - and the credentials shouldn's be there either ) .
I tried to look into IAM roles, but couldn't wrap my head around something that will help my use-case.
If you are running containers on an EC2 instance directly (without using ECS service) then you need to create an IAM role and attach appropriate policy to it (such as AmazonS3FullAccess, if you need all rights for S3, if you only need to read the contents of S3, then you can add AmazonS3ReadOnlyAccess policy). After you have created this role you can attach it to the EC2 instance where you are running your container.
If you are using ECS service, then you can attach this role to the task in which you define your containers (it is still possible to attach it to the underlying EC2 container instance - but only in case of EC2 launch type, not Fargate - for the container to assume that role, but it is preferred to be as granular as possible - individual tasks having their own roles).
You should never add AWS credentials to your code or store them in an EC2 instance/container, that is why you have roles.
