Motivation

This script is intended to allow generating and signing REST requests to AWS API with signature version 4. It is helpful in cases when no SDK/AWS CLI, but bash is available in the environment.

Requirements

• The script uses AWS EC2 instance profile temporary credentials to sign requests, therefore it can run "as is" only on EC2 instances with a profile associated.
• The IAM role must have necessary permissions.
• OpenSSL and cURL command line tools need to be installed.
• You can use this script with the most AWS APIs, but it was only tested with the GetParameters API of AWS Systems Manager. You will have to customize it for other use cases and AWS APIs.
• A parameter stored in AWS Systems Manager Parameter Store in the same region, as the AWS EC2 instance the script running on.

How to run

bash -c ". aws-api.sh /example/ssm/parameter"