Assumes an AWS IAM role and exports temporary AWS_* credentials.

mfa.sh

#!/bin/bash
#### Description: Assumes an AWS IAM role and export temporary AWS_* credentials.
#### Written by: Nick den Engelsman - nick@bandlab.com on 2017-05
####
#### Setup:
####   1. npm install -g aws-auth-helper
####   2. save this script as ~/.aws/mfa.sh
####   3. chmod +x ~/.aws/mfa.sh
####
#### Edit your .bash_rc (or something else):
####   alias aws-auth="source ~/.aws/mfa.sh $1"
####
#### Usage:
####   aws-auth [PROFILE]

# Make sure previous sessions are cleaned
AWS_ACCESS_KEY_ID=""
AWS_SECRET_ACCESS_KEY=""
AWS_SESSION_TOKEN=""

# Configure the aws auth helper
AWS_CONFIG_FILE="~/.aws/config"
AUTH_HELPER=$(which aws-auth-helper)

# Obtain credentials
eval `$AUTH_HELPER $1`

# Export newly obtained credentials
export AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID
export AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY
export AWS_SESSION_TOKEN=$AWS_SESSION_TOKEN