Script to fetch an MFA token for you to use temporary aws access credentials

I got this somewhere on github and made some changes to it to require less parameters and remember my MFA ARN.

The profile name should be the name of the profile stanza in your ~/.aws/credentials file as used by the aws-cli.

The ARN should be the ARN of your MFA device as specified in the AWS console.

The MFA code is the code your MFA device gives you.

1. Extract the files to any directory you want.
2. Add source /path/to/alias.sh to your ~/.bashrc or ~/.zshrc
3. Copy SAMPLE-mfa.cfg to mfa.cfg in the same directory.
4. Add a profile name and MFA ARN for each aws cli profile you wish to use. The key should be the profile name and the value should be the ARN of the MFA to use for that profile.

At a command prompt run the following command.

mfa <mfacode> <optional-aws-profile>

Scripts run in a subprocess of the calling shell. This means that if you attempt to set the env vars in the script, they will only persist inside that subprocess. The alias.sh script sets an alias function to source the env vars into your main shell whenever you run the mfa command.