role:~/environment $ 
role:~/environment $ rolearn=$(aws cloud9 describe-environment-memberships --environment-id=$C9_PID | jq -r '.memberships[].userArn')
role:~/environment $ 
role:~/environment $ echo ${rolearn}
arn:aws:sts::xxxxxx8:assumed-role/role/seo
role:~/environment $ 
role:~/environment $ eksctl create iamidentitymapping --cluster eks-demo --arn ${rolearn} --group system:masters --username admin
2021-09-21 04:18:42 [ℹ]  eksctl version 0.67.0
2021-09-21 04:18:42 [ℹ]  using region us-west-1
Error: arn is neither user nor role
role:~/environment $ 
role:~/environment $ assumedrolename=$(echo ${rolearn} | awk -F/ '{print $(NF-1)}')
role:~/environment $ rolearn=$(aws iam get-role --role-name ${assumedrolename} --query Role.Arn --output text) 
role:~/environment $ 
role:~/environment $ eksctl create iamidentitymapping --cluster eks-demo --arn ${rolearn} --group system:masters --username admin
2021-09-21 04:19:00 [ℹ]  eksctl version 0.67.0
2021-09-21 04:19:00 [ℹ]  using region us-west-1
2021-09-21 04:19:01 [ℹ]  adding identity "arn:aws:iam::222222222222:role/role" to auth ConfigMap
role:~/environment $ 
role:~/environment $ echo ${rolearn}
arn:aws:iam::222222222222:role/seo-admini



seo-administrator-role:~/environment $ kubectl describe configmap -n kube-system aws-auth
Name:         aws-auth
Namespace:    kube-system
Labels:       <none>
Annotations:  <none>

Data
====
mapRoles:
----
- groups:
  - system:bootstrappers
  - system:nodes
  rolearn: arn:aws:iam::22222222:role/eksctl-eks-demo-nodegroup-node-gr-NodeInstanceRole-1EVHH6VHYXA
  username: system:node:{{EC2PrivateDNSName}}
- groups:
  - system:masters
  rolearn: arn:aws:iam::22222222:role/seo-administrator-role
  username: admin

mapUsers:
----
[]

Events:  <none>