utility-tools

Small tools for users of Lumi

Shared settings are in settings.sh Here you can set the timeouts, toggle if ssh to compute nodes is enabled and change the name of the supercomputer.

SSH

Minimal ssh server + client using dropbear to use on compute nodes. Use only for debugging.

Just copy/move the SSH folder to where you want to have it installed run setup.sh and add the bin folder to your path

start-ssh-server will launch the server and job-ssh <jobid> <node> [optinal commands] will then allow you to ssh to the node

To avoid clutter in $HOME all keys are generated per job basis under the installation directory.

dump.mp4

A much more light weight alternative is to just use dropbear directly:

Starting the server

mkdir -p /tmp/$USER && dropbearkey -t ed25519 -f /tmp/$USER/drop_id && dropbear -F -m -p 4040 -E -r /tmp/$USER/drop_id

Generting connection keys (only one time needed)

dropbearkey -t ed25519 -f $HOME/.ssh/drop_ssh_key  | grep "^ssh-ed25519" >> $HOME/.ssh/authorized_keys

Connecting

dbclient -i $HOME/.ssh/drop_ssh_key -p 4040 nid005032

start-jupyter

Will start a juptyer notebook and print connection information so that users can forward a port to Lumi and then connect to the notebook in their local browser.

VNC

Scripts for starting a minimal vnc server + novnc proxy

• _start_vnc main script responsible for starting the VNC and proxy
• _get_vnc_display runs the main script in the background and sets DISPLAY+some utility functions. The utility function are
  • stop-vnc stops the vnc, resets DISPLAY and removes and related functions
  • vnc-status returns 0 if the vnc is running
  • vnc-info Prints the connection information for the vnc

_get_vnc_display has to be sourced so that the variables and utility function can be set in the current shell. This can be achieved by:

1. source /path/to/_get_vnc_display
2. alias start-vnc="source /path/to/_get_vnc_display"
3. function start-vnc { source /path/to/_get_vnc_display "$@" ;} && export -f start-vnc

Aliases are not exported to subshells + shopt -s expand_aliases does not help us with sbatch scripts. So the alias needs to be set in the job file (e.g by loading a module) and can not be inherited from the submission environment.

Note, the vnc script does not start any program so connecting works but only a gray screen is shown before some programs are started The base container includes xterm which can be used as a sanity check

As the vnc is sourced a job will end after the last command is done If for some reason this is not wanted and extra wait has to be added to the end of the script