Bash script for logging into AWS with MFA (and into ECR)

login_aws_mfa.sh

#!/bin/bash

# Usage:   `source login_aws_mfa.sh <account id> <name> <mfa code>`
# Example: `source login_aws_mfa.sh 454099695756 john 123456`

{
  AWS_ACCESS_KEY_ID= && \
  AWS_SECRET_ACCESS_KEY= && \
  AWS_SESSION_TOKEN= && \
  token=$(aws sts get-session-token --serial-number arn:aws:iam::$1:mfa/$2 --token-code $3) && \
  keyval=$(echo $token | sed 's/{ "Credentials"://' | awk '{gsub("\"|{|}| ", "")} {gsub(":", "=")} {print $0}' | tr ',' '\n') && \
  export AWS_ACCESS_KEY_ID=$(echo $keyval | tr ' ' '\n' | sed -n 's/^AccessKeyId=//p') && \
  export AWS_SECRET_ACCESS_KEY=$(echo $keyval | tr ' ' '\n' | sed -n 's/^SecretAccessKey=//p') && \
  export AWS_SESSION_TOKEN=$(echo $keyval | tr ' ' '\n' | sed -n 's/^SessionToken=//p')
} && {
  echo ""
  echo "Success! You are now logged in to AWS with MFA."
  echo "You should now be able to login to our docker registry with the following command:"
  echo ""
  echo "    aws ecr get-login-password --region eu-west-1 | docker login --username AWS --password-stdin 454099695756.dkr.ecr.eu-west-1.amazonaws.com"
  echo ""
}