Scala Ammonite Script to update AWS session token in awscli profile via 2FA

aws-mfa.sc

import $ivy.`io.circe::circe-core:0.10.0`;import $ivy.`io.circe::circe-generic:0.10.0`;import $ivy.`io.circe::circe-parser:0.10.0`
import sys.process._
import io.circe._

@doc("This script updates the awscli profile with the keys and the session token from AWS")
@main def authenticate(mfaArn: String @doc("// you can find the mfa arn in https://console.aws.amazon.com/iam/home#/users/<your aws console login username>?section=security_credentials"), 
                       token: String @doc("the token code from you authenticator app e.g. Google Authenticator or Authy"), 
                       @doc("the profile to use to get the session token, you can configure it with `aws configure --profile <profile name>`") stsProfile: String = "mfa", 
                       @doc("the profile to store the session keys and session token") sessionProfile: String = "mfa-session") = {
  assert(!stsProfile.equals(sessionProfile), "sts profile and session profile must not be the same")

  val sessionCommand = s"aws sts get-session-token --serial-number $mfaArn --token-code $token --profile $stsProfile --output json"
  val sessionProperties = parser.decode[Json](sessionCommand.!!).right.get.asObject.get("Credentials").get.asObject.get

  val accessKey = sessionProperties("AccessKeyId").get.asString.get
  val secretKey = sessionProperties("SecretAccessKey").get.asString.get
  val sessionToken = sessionProperties("SessionToken").get.asString.get

  s"aws configure set aws_access_key_id $accessKey --profile $sessionProfile".!
  s"aws configure set aws_secret_access_key $secretKey --profile $sessionProfile".!
  s"aws configure set aws_session_token $sessionToken --profile $sessionProfile".!
}