Description:

Create sts cluster with only master iam role or only worker iam role set will cause error cluster

How reproducible:

100%

Steps:

1. Create a sts cluster with only aws.sts.custom_iam_role.worker_iam_role or aws.sts.custom_iam_role.master_iam_role set
2. Check cluster creation log

Actual result:

Cluster will become error status with error logs

install logs for sts cluster With only worker_iam_role:

http://pastebin.test.redhat.com/966701

install logs for sts cluster With only master_iam_role:

http://pastebin.test.redhat.com/966734

pvasanth_openshift If it is not an issue in CMS, please feel free to move it to the correct team