How to make passwordless sudo to become a specific user?

Question

linux

# which sudo
/usr/bin/sudo

And in sudoers:

vasya ALL=(ALL:ALL) NOPASSWD: /usr/bin/sudo -iu pupkin

Doesn't work. How right?

The following code:
vasya ALL=(ALL:ALL) NOPASSWD: /usr/bin/apt update

Works. I sin on the keys, but the sudo editor does not swear at the syntax.

Answer 1

If so
vasya ALL=NOPASSWD: /usr/bin/sudo -iu pupkin

Answer 2

In your case, it’s easier not to configure sudo, but
add a line to /etc/pam.d/su
auth sufficient pam_succeed_if.so user = vasya
and write
su vasya