Managed policy is read incorrectly from config map

[kshamajain99]

Is this a BUG REPORT or FEATURE REQUEST?:
Bug

What happened:
For my usecase, I don't want to provide any managed policy. Hence, I removed field iam.managed.policies from iam-manager config map. But, I am still getting following error.

2020-10-27T22:05:46.575Z ERROR awsapi.iam.CreateRole Error while attaching managed policy {"request_id": "f31f3be2-787c-4a2a-8eba-36e0d3fbef3d", "roleName": "k8s-chaos-ns", "policy": "arn:aws:iam::233444812205:policy/", "error": "InvalidInput: ARN arn:aws:iam::233444812205:policy/ is not valid.\n\tstatus code: 400, request id: 32448561-3ec2-4a78-bb5b-9000cb4ed514"}

Based on golang behaviour, even when managed policy field is empty string ("") in config map. When you do strings.split, it will return list of string having length 1 and first element as empty string "".

iam-manager/internal/config/properties.go

Line 176 in ce0b5f9

managedPolicies := strings.Split(cm[0].Data[propertyManagedPolicies], separator)

https://play.golang.org/p/qazwf1dYDPY
What you expected to happen:
IAM role should create successfully

How to reproduce it (as minimally and precisely as possible):
Remove managed policies field from config map.

[sumitnagal]

@kshamajain99 , here are some error which I encounter setup on a cluster
➜ snagal git:(master) ✗ k get Iamrole
NAME STATE ROLENAME RETRYCOUNT LASTUPDATEDTIMESTAMP AGE
iamrole-pfi Error k8s-chaos-ns 1 2020-10-27T19:27:06Z 87m

After following the steps

1. kubens iam-manager-system
2. kubectl edit cm iam-manager-iamroles-v1alpha1-configmap
3. Remove "iam.managed.policies: shared.snagal-eks-k8s-ppd"

Found this error k describe Iamrole iamrole-pfi

`Status:
Error Description: InvalidInput: ARN arn:aws:iam::233444812205:policy/ is not valid.
status code: 400, request id: 060bad11-fbed-4759-ba47-c04b00df9e12
Last Updated Timestamp: 2020-10-27T21:11:47Z
Retry Count: 11
Role Name: k8s-chaos-ns
State: Error
Events:
Type Reason Age From Message

---

Warning Error 4m47s iam-manager Unable to create/update iam role due to error InvalidInput: ARN arn:aws:iam::233444812205:policy/ is not valid.
status code: 400, request id: bd2f6f82-6312-41d1-965a-5b2723639150
Warning Error 4m46s iam-manager Unable to create/update iam role due to error InvalidInput: ARN arn:aws:iam::233444812205:policy/ is not valid.
status code: 400, request id: e9f9c6a0-c833-4a95-95b5-163abeac6396
Warning Error 4m44s iam-manager Unable to create/update iam role due to error InvalidInput: ARN arn:aws:iam::233444812205:policy/ is not valid.
status code: 400, request id: e63f5bdf-c10d-4038-9700-fa70b22373de`