AWS CLI Profile Switching Made Easy

Why did i write this script?

I use the AWS CLI client a lot at work, and need to constantly switch between different accounts.

I wrote this handy little Bash script that makes it easy to switch between profiles on the fly.
Script has been tested to work with Bash 5 on Ubuntu 20.04 and macOS Catalina (Version 10.15.7)

The script

#!/bin/bash

# check args
if [[ $# -ne 1 ]]; then
    echo "usage: aws-profile <profile name>"
    echo "profiles can be defined in ~/.aws/credentials"
    exit 0
else
    # save original profile before exporting
    original_profile=$(echo $AWS_DEFAULT_PROFILE)
    export AWS_DEFAULT_PROFILE=${1}
fi

# Check if profile exists, revert if not
aws configure list
if [[ $? != 0 ]]; then
    echo "aborting.."
    export AWS_DEFAULT_PROFILE=${original_profile}
    echo -e "\nDone"
else
    echo -e "\nOK"
    echo "switched to profile: ${1}"
fi

How it works

AWS CLI reads both the access and secret keys from environment variables AWS_ACCESS_KEY and AWS_SECRET_ACCESS_KEY respectfully.

Another way to supply the credentials is to create profiles in ~.aws/credentials and point the AWS_DEFAULT_PROFILE environment variable to one of them.

Here is a quick rundown on how the script works:

• Check the arguments. If there is not exactly one argument, print usage information and exit.
• Save whatever profile the user is currently using in case something goes wrong.
• Set the AWS_DEFAULT_PROFILE variable to whatever value we got as the argument
• Run aws configure list, if exit code is 0 -> quit program.
• If exit code was not 0, revert to the profile the user was using before they ran the script.

How to use it

You need to have AWS CLI installed (left as an excercise to the reader). Make sure ~.aws/credentials file exists, and if it doesn’t, run aws configure or create it manually.

Example credentials file:

[default]
region = eu-north-1
AWS_ACCESS_KEY = foo
AWS_SECRET_ACCESS_KEY = bar

[client1]
region = eu-west-1
AWS_ACCESS_KEY = xyz
AWS_SECRET_ACCESS_KEY = asdfgh

Bonus tip

Put the script in /usr/local/bin and create a bash alias:

alias awsprofile="bash /usr/local/bin/aws_profile_switcher.sh"