Multiplex Setup

Setting up multiplexing¶

This document briefly details how user/developers can set up multiplexing. Multiplexing is a reasonably secure way to reduce the number of times that users have to type passwords when connecting to remote resources.

Multiplexing for the local host.¶

This section describes how to set up multiplexing for the local host.

Step 1¶

Create a local file named ~/.ssh/config, or append to it.

In this file, you need the following block

Host lh
   User <your-local-username>
   HostName localhost
   ControlPath ~/.ssh/controlmasters/%r@%h:%p
   ControlMaster auto
   ControlPersist 30m

The duration of ControlPersist can be modified to suit your needs. Note however that shorter durations are more secure.

Step 2¶

Create a directory using mkdir ~/.ssh/controlmasters

Step 3¶

Modify your existing machines_user.yml file such that it contains the following:

localhost:
  username: <username>
  remote: lh
  manual_ssh: true

Multiplexing for remote HPC¶

This section describes how to set up multiplexing for a remote machine. The documentation uses the ARCHER2 supercomputer as an example.

Step 1¶

Create a local file named ~/.ssh/config, or append to it.

In this file, you need the following block

Host archer2
   User <archer2-username>
   HostName login.archer2.ac.uk
   ControlPath ~/.ssh/controlmasters/%r@%h:%p
   ControlMaster auto
   ControlPersist 30m

Step 2¶

Create a directory using mkdir ~/.ssh/controlmasters

Step 3¶

Modify your existing machines_user.yml file such that it contains the following:

archer2:
  username: <username>
  remote: archer2
  manual_ssh: true
  project: <project>
  budget: <budget>