How to add policy to assumed user? Or why is it not possible?

Question

Amazon Web Services

hello everyone,

with help

aws sts assume-role --role-arn arn:aws:iam::123456789012:role/miniadmin --role-session-name temporary

I get user credentials which I then use as env variables: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN and call various functions like
aws ec2 describe-instances etc

in account 123456789012 there is also an access policy (s3bucketput) that I would like to add to the existing one /temporary session-user. It seems that the miniadmin role has full access to IAM in this account. The question is how to do it, the challenge

aws iam attach-user-policy --policy-arn arn:aws:iam::123456789012:policy/s3bucketput --user-name miniadmin

returns no user miniadmin, which is generally true. With this in the aws console, I can add this policy (s3bucketput) to the miniadmin role with no problem! But you need from CLI

good day and night)
Vadim

Answer 1

Everything works Ivan Shumov )) - you just need to add the desired policies when calling
sts assume-role using the argument --policy-arns (list)