Updating IOS's via SCP in bash with expect - ios

Question

Good day. I am attempting to create/run a script that will allow me to send an updated IOS from a server to my network devices. The following code works when I put in a manual IP address right before the ":flash" command.
#!/user/bin/expect
set IOSroot "/xxxxx/xxx/c3750e-universalk9-mz.150-2.SE10a.bin"
set pw xxxxxxxxxxxxxxxxxxx
spawn scp $IOSroot 1.1.1.1:flash:/c3750e-universalk9-mz.150-2.SE10a.bin
expect "TACACS Password:"
send "$pw\r"
interact
The code there works great and as expected. The issue arises when I try to use a file called "ioshost" with a list of IP's and use that within this script to get some automation. I have tried various things to get this to work. Some of them are as follows:
Settings Variables
IPHosts=$(cat ioshost)
set IPHost 'cat ioshost'
Along with trying to use the read/do command...
while read line; do
spawn scp $IOSroot $line:flash:/c3750e-universalk9-mz.150-2.SE10a.bin
done < ioshost
None of these seem to work and I am looking for guidance. Please note I understand that setting a password is not best practice but setting RSA keys as mentioned in other articles is not allowed so I am forced to do it this way.
Thank you for your time.

Answer 1

You can use one Expect script and one Bash script.
First update your Expect script a bit:
#!/user/bin/expect
set IOSroot "/xxxxx/xxx/c3750e-universalk9-mz.150-2.SE10a.bin"
set pw xxxxxxxxxxxxxxxxxxx
spawn scp $IOSroot [lindex $argv 0]:flash:/c3750e-universalk9-mz.150-2.SE10a.bin
# ^^^^^^^^^^^^^^^^
expect "TACACS Password:"
send "$pw\r"
interact
Then write a simple Bash for loop:
for host in $(<ioshost); do
expect /your/script.exp $host
done