append-pubkey.exp

#!/usr/bin/env expect
set user "your_username"
set prompt ".*$user.*"
set domain "subdomain.yourdomain.com"
set timeout 60

if { $argc < 2 } {
  puts "usage: $argv0 <public-key-absolute-path> <ssh-password>
  Append a public key to ~/.ssh/authorized_keys of $user@$domain
  ex) $ ./append-publickey.exp /home/foobar/.ssh/id_rsa.pub abc123
"
  exit 1
}

set pubkey_path [lindex $argv 0]
set password [lindex $argv 1]

### Copy a public key to a domain at $HOME
spawn scp $pubkey_path $user@$domain:./
sleep 1
expect "password: "
send "$password\r"
expect -re $prompt

### Log in with password and append the public key to authorized_keys
spawn ssh $user@$domain
sleep 1
expect "password: "
send "$password\r"
expect -re $prompt

set pubkey_name [file tail $pubkey_path]
send "cat ~/$pubkey_name >> ~/.ssh/authorized_keys\r"
send "chmod 600 ~/.ssh/authorized_keys\r"
send "chmod 700 ~/.ssh\r"
send "rm ~/$pubkey_name\r"
expect -re $prompt

### Exit the session
send "exit\r"
expect eof