Efficient way of sending commands?

Domin43

Hi LET,

What do you use to send commands to multiple servers at once?

SplitIce

use a bit of bash and pipe the commands to ssh?

gitreset

Automatic or manual?

If automatic:
python + paramiko

If manual:
tmux, sync panes

Ishaq

Or you can use something like SaltStack, or Ansible, and others to remotely manage and execute commands to your infrastructure.

Domin43

Well what's the best way you think. My current method is @SplitIce but needs to become easier because why not.

SplitIce

Just FYI, we use Ansible for deployment. Normally though you dont "execute commands" with it.

You define a configuration state for each service a server has, then send to ansible for deployment. Or at-least thats how you should do it.

raindog308

SplitIce said: Just FYI, we use Ansible for deployment. Normally though you dont "execute commands" with it.

Yeah.

Writing your own command executor isn't hard:

#!/bin/bash

key=/root/.ssh/some-passwordless-private-key

while read host ; do
  ssh -i ${key} -p ${my_port} root@${host} ${some_command}
done < /some/list/of/hosts.txt

Notes:

• you need to setup authorized_keys for that private key, of course
• you should use prohibit-password (or "without-password") for PermitRootLogin in sshd_config
• quoting in the above is a pain
• stdout/stderr capturing is a pain

You might consider scping a script and executing it, which avoids some of these problems.

vfuse

RoyalTS or RoyalTSX has a broadcasting feature to send command to multiple servers.

elgs

I use pssh.

jtk

Unix-based command line tools such as pdsh or GNU parallel might be what you want.

ricardo

GNU parallel

Was going to say that one.

I'd SCP/rsync a bash script to each server like Raindog suggests (if its more than one or two commands) and then run the command. You can use exit codes from the bash script if you need an indication of what happened.

jar

+1 for SaltStack. Super easy.