Assume a Role

A role is assigned a specific set of tasks and permissions. Users may assume a different role than the one they have in order to perform a different set of tasks. For example, the primary administrator is unavailable and the backup administrator is asked to assume the role of the primary administrator during his or her absence. A few points to consider before assuming a role:

  • A role must first be set up by an administrator.
  • You must log in as an IAM user, not as an account root user.
  • Once you assume another role, you temporarily give up your existing user permissions and assume the permissions of your new role.
  • When you are no longer assuming another role, your usual user permissions are automatically restored.

Create Role

The scenario described in this section outlines the procedure for creating a role in order to delegate permissions to an IAM user.Create a role that allows users of an account to manage keypairs. Management of keypairs include the following EC2 actions:

  • CreateKeyPair

  • DeleteKeyPair

  • DescribeKeyPairs

  • ImportKeyPair Create a role for managing keypairs for the account. In this example, the admin user of ‘devops’ account (001827830003) is creating the role:

    cat devops-role-trustpolicy.json

    { “Version”: “2012-10-17”, “Statement”: [{ “Effect”: “Allow”, “Principal”: {“AWS”: “arn:aws:iam::001827830003:root”}, “Action”: “sts:AssumeRole” }] }

    euare-rolecreate -f devops-role-trustpolicy.json devops-ec2-keypair-mgmt-role –region devops-admin@future

Add IAM access policy for keypair management to the role:

# cat keypair-mgmt-policy.json
  "Version": "2012-10-17",
  "Statement": [
      "Sid": "Stmt1445362739663",
      "Action": [
      "Effect": "Allow",
      "Resource": "*"

# euare-roleuploadpolicy --policy-name ec2-keypair-actions --policy-document keypair-mgmt-policy.json devops-ec2-keypair-mgmt-role --region devops-admin@future

Now that the role has been created, follow the AWS IAM best practice of using groups to assign permission to IAM users and attach an IAM access policy to the group to allow any members (example shows ‘user01’ user) to assume the ‘devops-ec2-keypair-mgmt-role’ role:

# euare-groupcreate -g Key-Managers --region devops-admin@future
# euare-groupadduser -u user01 -g Key-Managers --region devops-admin@future
# cat devops-keypair-mgmt-assume-role-policy.json
 "Version": "2012-10-17",
 "Statement": [{
 "Effect": "Allow",
 "Action": "sts:AssumeRole",
 "Resource": "arn:aws:iam::001827830003:role/devops-ec2-keypair-mgmt-role"
# euare-groupuploadpolicy -p keypair-mgmt-role-perm -f devops-keypair-mgmt-assume-role-policy.json Key-Managers --region devops-admin@future

Now that members can assume the ‘devops-ec2-keypair-mgmt-role’ role, run the following command to list all keypairs under the account:

# eval `/usr/bin/euare-assumerole devops-ec2-keypair-mgmt-role --region devops-user01@future`
# euca-describe-keypairs --region @future
KEYPAIR	devops-admin	9e:1a:bc:ac:98:b1:97:7c:65:b0:b3:7c:96:f5:d5:7b:a1:3e:36:a6

When done assuming the role, the role must be released using euare-releaserole :

# eval `/usr/bin/euare-releaserole --region devops-user01@future`