Trying to Create a remote login tool: "interact" in "expect << EOF" does not work

Question

The use case of this script is I have various servers with different ssh keys. I am trying to write a script so when called will log into the specified server. An example of usage would be:

    ./ServerLogin.sh Server1

I feel that I am fairly close, but The last part of expect interact is tripping me up. This is a simplified version:

#!/bin/bash

ServerName="$1"
case $ServerName in 
  "Server1") IP="1.2.3.4" ; keyPath="/path/to/key.pem" ; password="password" ; break ;;
  *)         echo "Server not recognized" ; exit ;;
esac 

/usr/bin/expect << EOD
spawn ssh -i $keyPath user@$IP
expect "*.pem': "
send "$password\r"
interact
EOD

The result of this is it logs in and immediately closes. I want for the session to remain interactable.

Any ideas?

Answer 1

The problem is in expect << EOF. With expect << EOF, expect's stdin is the here-doc rather than a tty. But the interact command only works when expect's stdin is a tty. Your answer is one solution. Another solution is to use expect -c if you prefer not using a tmp file.

expect -c "
  spawn ssh -i $keyPath user@$IP
  expect \"*.pem': \"
  send \"$password\r\"
  interact
"