Sometimes it’s handy to be able to quickly change the password of an existing IAM user without having to login at the AWS Console to do it. I generally set a long random password using a tool called apg, although I’ve found that AWS don’t like certain characters so I’ve added a few exclusions with the -E option.
First, make sure you have the awscli installed, then:
aws iam update-login-profile --user-name $IAM_USERNAME --password-reset-required \
--password $(apg -n1 -MSNCL -E\`\'\*\?\"\&\;\\\:\{\}\,\.\~\|\/\< -m24 | tee /dev/stderr)
In the command above replace $IAM_USER with the actual user you wish to change the password for. The new password will be echoed to your terminal, but you could pipe it the clipboard with | xclip -sel clip rather than display it onscreen if you prefer.