How can I automate running commands remotely over SSH to multiple servers in parallel?

Question

I\'ve searched around a bit for similar questions, but other than running one command or perhaps a few command with items such as:

ssh user@host -t sudo su -         


        

Answer 1

To give you the structure, without actual code.

1. Use scp to copy your install/setup script to the target box.
2. Use ssh to invoke your script on the remote box.

Answer 2

Just read a new blog using setsid without any further installation/configuration besides the mainstream kernel. Tested/Verified under Ubuntu14.04.

While the author has a very clear explanation and sample code as well, here's the magic part for a quick glance:

#----------------------------------------------------------------------
# Create a temp script to echo the SSH password, used by SSH_ASKPASS
#----------------------------------------------------------------------
SSH_ASKPASS_SCRIPT=/tmp/ssh-askpass-script
cat > ${SSH_ASKPASS_SCRIPT} <<EOL
#!/bin/bash
echo "${PASS}"
EOL
chmod u+x ${SSH_ASKPASS_SCRIPT}

# Tell SSH to read in the output of the provided script as the password.
# We still have to use setsid to eliminate access to a terminal and thus avoid
# it ignoring this and asking for a password.
export SSH_ASKPASS=${SSH_ASKPASS_SCRIPT}
......
......
# Log in to the remote server and run the above command.
# The use of setsid is a part of the machinations to stop ssh 
# prompting for a password.
setsid ssh ${SSH_OPTIONS} ${USER}@${SERVER} "ls -rlt"