Script for account/identity switching while using Amazon AWS Cloud tools

iam-switch.sh

#!/bin/bash
###############################################
#
# Script for switching identities while working with Amazon AWS.
# Sets environment variables used by AWS tools.
#
# Copyright (c) 2010 by Jozef Sovcik, http://www.vanilladesk.com
#
#---------------------------------------------
# How to use:
# 1) create folder 'aws' in your home folder
#    $ mkdir aws
# 2) in folder 'aws' create sub-folder for each identity you
#    would like to use (identity=AWS account or user of AWS account)
#    $ mkdir account1
# 3) for each identity create/copy necessary files
#    a) identity file 'aws-credentials'
#       (should contain access key id and secret access key)
#       see http://docs.amazonwebservices.com/IAM/2010-05-08/GettingStartedGuide/
#    b) private key 'pk-current.pem'
#       (idea: generate a key and create 'pk-current.pem' as symlink to it)
#    c) certificate file 'cert-current.pem'
#       (idea: generate a certificate and create 'cert-current.pem' as symlink to it)
# 4) call this script using shell command 'source' in order to modify
#    existing environment with
#    $ source iam-switch.sh <identity folder name>
# 5) calling this script without any paramaters only shows the current identity
#
###############################################


function set_aws_id() {
  local awsid="$1"

  if [ ! "$awsid" ]; then
    echo "AWS Identity Switch"
    echo "Current AWS Identity: $AWSI_NAME"
    return 0
  fi

  local awsid_fld=~/aws/$awsid

  if [ ! -d "$awsid_fld" ]; then
    echo "Error: Folder $awsid_fld does not exist."
    return 1
  fi

  export EC2_PRIVATE_KEY=$awsid_fld/pk-current.pem
  export EC2_CERT=$awsid_fld/cert-current.pem
  export AWS_CREDENTIAL_FILE=$awsid_fld/aws-credentials
  export AWSI_NAME=$awsid

  echo "New AWS Identity: $AWSI_NAME"
  return 0
}

set_aws_id $1