Assume CloudFormation Write Role

A skill to obtain the necessary credentials for AWS CloudFormation stack operations (create, delete, update) and set them as environment variables.

Purpose

Before CloudFormation operations, assume the specified role to obtain temporary credentials and set them as environment variables that can be used by AWS CLI.

Input Parameters

• profile: AWS CLI profile name (default: <profile-name>)
• role_arn: IAM role ARN to assume (default: arn:aws:iam::<AWS_ACCOUNT_ID>:role/<RoleName>)
• role_session_name: Session name (default: cfn-write)

Execution Steps

1. Use AWS STS to assume the role and obtain credentials
2. Save credentials to a temporary file
3. Parse credentials using jq and set as environment variables
4. Clean up the temporary file

Command Example

# Assume role and obtain credentials
aws sts assume-role \
  --role-arn arn:aws:iam::<AWS_ACCOUNT_ID>:role/<RoleName> \
  --role-session-name cfn-write \
  --profile <profile-name> \
  > /tmp/creds.json

# Set environment variables
export AWS_ACCESS_KEY_ID=$(jq -r '.Credentials.AccessKeyId' /tmp/creds.json)
export AWS_SECRET_ACCESS_KEY=$(jq -r '.Credentials.SecretAccessKey' /tmp/creds.json)
export AWS_SESSION_TOKEN=$(jq -r '.Credentials.SessionToken' /tmp/creds.json)

# Remove temporary file
rm /tmp/creds.json

Output

Environment variables are set, making CloudFormation operations available via AWS CLI:

• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY
• AWS_SESSION_TOKEN

Usage Examples

After executing this skill, the following CloudFormation commands become available:

# Create stack
aws cloudformation create-stack --stack-name my-stack --template-body file://template.yaml

# Update stack
aws cloudformation update-stack --stack-name my-stack --template-body file://template.yaml

# Delete stack
aws cloudformation delete-stack --stack-name my-stack

Prerequisites

• AWS CLI installed
• jq command installed
• Specified profile configured in ~/.aws/credentials or ~/.aws/config
• Source profile has sts:AssumeRole permission for the specified role

Notes

• Credentials are temporary and typically expire after 1 hour
• If credentials expire, re-execute this skill
• For security purposes, temporary files are always deleted after processing