switch-role

#!/usr/bin/env bash

set -e

script_dir=$(cd "$(dirname "$0")" ; pwd -P)
base_profile="${1}"
role_name="${2}"

target_profile=data-derp

usage() { echo "Usage: $0 [-b <base profile: string>] [-t <target role: string>]" 1>&2; exit 1; }

while getopts ":b:t:" o; do
    case "${o}" in
        b)
            base=${OPTARG}
            ;;
        t)
            target=${OPTARG}
            ;;
        *)
            usage
            ;;
    esac
done
shift $((OPTIND-1))

if [ -z "${base}" ] || [ -z "${target}" ] ; then
    usage
fi

identity=$(AWS_PROFILE=${base} aws sts get-caller-identity)
account=$(echo $identity | jq -r '.Account')
arn=$(echo $identity | jq -r '.Arn')

response=$(AWS_PROFILE=${base} aws sts assume-role \
--role-arn "arn:aws:iam::${account}:role/${target}" \
--role-session-name "bootstrap-$(echo $arn | cut -d '/' -f 3)")

aws configure set aws_access_key_id $(echo $response | jq -r '.Credentials.AccessKeyId') --profile "${target_profile}"
aws configure set aws_secret_access_key $(echo $response | jq -r '.Credentials.SecretAccessKey') --profile "${target_profile}"
aws configure set aws_session_token $(echo $response | jq -r '.Credentials.SessionToken') --profile "${target_profile}"

echo "Successfully switched role to arn:aws:iam::${account}:role/${target}. Credentials saved in profile: ${target_profile}."