assume-role: Add MFA support.

role="$1"

shift

if [ "$(aws iam list-mfa-devices --query 'length(MFADevices)')" -gt 0 ]

then

    printf "Enter the MFA token: "

    read -r mfa_token

    for mfa_dev in $(aws iam list-mfa-devices --query 'MFADevices[].SerialNumber' --output text)

    do

        credentials="$(aws sts get-session-token --output text --token-code "$mfa_token" --serial-number "$mfa_dev" 2>/dev/null)" || continue

        break

    done

    if [ -z "$credentials" ]

    then

        echo 'Failed to get a temporary token.' >&2

        exit 1

    fi

    AWS_ACCESS_KEY_ID="$(echo "$credentials" | awk '{print $2}')"

    AWS_SECRET_ACCESS_KEY="$(echo "$credentials" | awk '{print $4}')"

    AWS_SESSION_TOKEN="$(echo "$credentials" | awk '{print $5}')"

    export AWS_ACCESS_KEY_ID

    export AWS_SECRET_ACCESS_KEY

    export AWS_SESSION_TOKEN

    unset AWS_SECURITY_TOKEN

fi

if [ "$role" = "${role##arn:}" ]

then

    role_arn="$(aws iam list-roles --query "Roles[?RoleName==\`${role}\`].Arn" --output text)"