CLI to Switch Amazon AWS Shell Environment Credentials

I work with many different AWS IAM Accounts and need to easily switch between these accounts. The good news is the AWS CLI tools now support a standard config file (~/.aws/config) that allows you to create profiles  for  multiple accounts in the one config file. You can select them when using the aws-cli with the --profile flag.

But many other tools don’t yet support the new format config file or multi-profiles. But they do support shell environment variables. So I wrote a simple ruby script that

• Allows you to specify the profile name as an argument
• Reads in the config file ~/.aws/config
• Outputs the export statements for publishing the environment variables
  • You can eval the output to set the environment of your current shell session

So if you had a config file ~/.aws/config that looked like this:

[default]
aws_access_key_id=AKI***********2A
aws_secret_access_key=jt41************************************p
region=us-east-1

[profile foo]
aws_access_key_id=0K***************K82
aws_secret_access_key=2b+***********************************1g
region=us-east-1

[profile bar]
aws_access_key_id=AKI**************GA
aws_secret_access_key=MG************************************/d
region=us-east-1

If you don’t specify any argument to the command it will output the default profile:

 $ aws_switch
export AWS_ACCESS_KEY_ID=AKI***********2A
export AWS_SECRET_ACCESS_KEY=jt41************************************p
export AMAZON_ACCESS_KEY_ID=AKI***********2A
export AMAZON_SECRET_ACCESS_KEY=jt41************************************p
export AWS_ACCESS_KEY=AKI***********2A
export AWS_SECRET_KEY=jt41************************************p

If you specified a profile (in this case foo):

$ aws_switch foo
export AWS_ACCESS_KEY_ID=0K***************K82
export AWS_SECRET_ACCESS_KEY=2b+***********************************1g
export AMAZON_ACCESS_KEY_ID=0K***************K82
export AMAZON_SECRET_ACCESS_KEY=2b+***********************************1g
export AWS_ACCESS_KEY=0K***************K82
export AWS_SECRET_KEY=2b+***********************************1g

You would actually use it by eval’ing the output of aws_switch so it sets the variables in the environment of yhour current shell:

eval `aws_switch foo`

Here’s the code for aws_switch. Put it in someplace in your $PATH and make sure to chmod 0755 the file so its executable:

#!/usr/bin/env ruby
require 'inifile'

configs = IniFile.load(File.join(File.expand_path('~'), '.aws', 'config'))

profile_name_input = ARGV[0]
case profile_name_input
when 'default'
  profile_name = 'default'
when nil
  profile_name = 'default'
when ""
  profile_name = 'default'
else
  profile_name = "profile #{profile_name_input}"
end

id = configs[profile_name]['aws_access_key_id']
key = configs[profile_name]['aws_secret_access_key']

puts "export AWS_ACCESS_KEY_ID=#{id}"
puts "export AWS_SECRET_ACCESS_KEY=#{key}"
puts "export AMAZON_ACCESS_KEY_ID=#{id}"
puts "export AMAZON_SECRET_ACCESS_KEY=#{key}"
puts "export AWS_ACCESS_KEY=#{id}"
puts "export AWS_SECRET_KEY=#{key}"