What is the cleanest way to ssh and run multiple commands in Bash?

Question

I already have an ssh agent set up, and I can run commands on an external server in Bash script doing stuff like:

ssh blah_server "ls; pwd;"
         


        

Answer 1

The easiest way to configure your system to use single ssh sessions by default with multiplexing.

This can be done by creating a folder for the sockets:

mkdir ~/.ssh/controlmasters

And then adding the following to your .ssh configuration:

Host *
    ControlMaster auto
    ControlPath ~/.ssh/controlmasters/%r@%h:%p.socket
    ControlMaster auto
    ControlPersist 10m

Now, you do not need to modify any of your code. This allows multiple calls to ssh and scp without creating multiple sessions, which is useful when there needs to be more interaction between your local and remote machines.

Thanks to @terminus's answer, http://www.cyberciti.biz/faq/linux-unix-osx-bsd-ssh-multiplexing-to-speed-up-ssh-connections/ and https://en.wikibooks.org/wiki/OpenSSH/Cookbook/Multiplexing.