ec2-import-creds

#!/bin/sh
# shellcheck disable=SC2155

attached_role_name=$(curl -m 1 -s "http://169.254.169.254/latest/meta-data/iam/security-credentials")
credentials=$([ -n "$attached_role_name" ] && curl -m 1 -s "http://169.254.169.254/latest/meta-data/iam/security-credentials/$attached_role_name")
availability_zone="$(curl -m 1 -s "http://169.254.169.254/latest/meta-data/placement/availability-zone")"

get_key_value() {
  echo "$1" | grep "$2" | cut -d ':' -f 2 | cut -d '"' -f 2
}

strip_az_suffix() {
  echo "$1" | sed -e 's![a-z]$!!'
}

[ -n "$availability_zone" ] && export AWS_DEFAULT_REGION=$(strip_az_suffix "$availability_zone")
[ -n "$credentials" ] && export AWS_ACCESS_KEY_ID=$(get_key_value "$credentials" "AccessKeyId")
[ -n "$credentials" ] && export AWS_SECRET_ACCESS_KEY=$(get_key_value "$credentials" "SecretAccessKey")
[ -n "$credentials" ] && export AWS_SESSION_TOKEN=$(get_key_value "$credentials" "Token")