aws-ts-assume-role

AWS Resources Using AssumeRole

This example demonstrates how to use the AssumeRole functionality of the AWS provider in order to create resources in the security context of an IAM Role assumed by the IAM User running the Pulumi program.

Deploying the Example

These instructions assume you are familiar with running Pulumi programs written in TypeScript. Some other examples which describe each step in more detail are:

• aws-ts-eks - Deploying an AWS EKS cluster
• aws-ts-ruby-on-rails - Deploying a Ruby on Rails app to EC2 instances

Part 1: Privileged Components

The Pulumi program in create-role requires credentials with permissions to create an IAM User, an IAM Role, and assign an AWS Access Key to the user. The program creates a new, unprivileged user with no policies attached, and a role which specifies a trust policy allowing assumption by the unprivileged user. The role allows the s3:* actions on all resources.

You'll need to set the create-role:unprivilegedUsername configuration variable to the name of the unprivilged user, as well as the AWS region in which to operate.

$ cd create-role
$ npm install
$ pulumi stack init assume-role-create
$ pulumi config set create-role:unprivilegedUsername [email protected]
$ pulumi config set aws:region us-east-1
$ pulumi up

The program can then be run with pulumi up. The outputs of the program tell you the ARN of the Role, and the Access Key ID and Secret associated with the User:

$ pulumi stack output --json
{
    "accessKeyId": "AKIAI7JE74TLY2LOEIJA",
    "secretAccessKey": "<redacted>",
    "roleArn": "arn:aws:iam::<redacted>:role/allow-s3-management-ad477e6"
}

Part 2: Assuming the Role

The Pulumi program in assume-role creates an S3 bucket after assuming the Role created in Part 1. It should be run with the unprivileged user credentials created in Part 1. This can be configured as follows, from the assume-role directory, replacing assume-role-create with the name of your stack from Part 1.

$ cd assume-role
$ npm install
$ export AWS_ACCESS_KEY_ID="$(pulumi stack output --stack assume-role-create accessKeyId)"
$ export AWS_SECRET_ACCESS_KEY="$(pulumi stack output --stack assume-role-create secretAccessKey)"

The configuration variable roleToAssumeARN must be set to the ARN of the role allowing S3 access, and the AWS region must be set to the region in which you wish to operate:

$ pulumi stack init assume-role-assume
$ pulumi config set roleToAssumeARN "$(pulumi stack output --stack assume-role-create roleArn)"
$ pulumi config set aws:region us-east-1

The program can then be run with pulumi up. You can verify that the role is indeed assumed by looking at the CloudTrail logs of the bucket creation operation, or by commenting out the assumeRole configuration in the provider and ensuring creation is not successful.