Using expect to log into VPN from a bash script

Question

I connect to a VPN from console using something like:

sudo openvpn my.conf
[sudo] password for user:
Enter Auth Username:my_user
Enter Auth Password:

I don't care about entering the admin pwd manually but I want to automate the vpn auth, I think expect is what I need to do this but I don't know how to use it and I never coded a bash script.

Could someone show me a simple bash script using expect so I can use it for this?

Answer 1

Something like that (untested)

#!/bin/usr/expect -f
spawn sudo openvpn my.conf
expect -r "\[sudo\] .*\: " {
    send "my_ownpassword\n"
}
expect "Enter Auth Username:" {
    send "my_user\n"
}
expect "Enter Auth Password:" {
    send "my_vpnpassword\n"
}
interact

Answer 2

Or maybe like this:

#!/usr/bin/expect -f  

# Constants  
set user "my_user"  
set pass "blablabla"  
set sudo_pass "blablabla"  
set timeout -1  

# Options  
match_max 100000  
log_user 0  

# Access to device  
spawn sudo openvpn my.conf
expect "[sudo]*"  
send -- "$sudo_pass\r"  

expect "*?sername:*"  
send -- "$user\r"

expect "*?assword:*"  
send -- "$pass\r"

interact
close

Answer 3

!/usr/bin/expect -f

creditability

set user "username"
set pass "password"

spawn openvpn file.ovpn

expect "?sername:"
send -- "$user\r"

expect "?assword:"
send -- "$pass\r"

interact close