TiledViz Dev Intro

TiledViz Dev Intro

Thoses containers are launched (in test_job.py for example) on the HPC machine. You may use TVConnections/Swarm/launch_dockers script.

Using docker on HPC machine represent a security breach because one user with docker rights can escaladate to root.

With a new connection a special ssh id is created and propagated to user chain of frontends and use in HPC containers to exchange secured data and RPC (VNC) streams to be share by other invited users in the secured web session.

For TiledViz client browser, best usage comes with a scale factor at 0.25 to watch all tiles in a full view of the visualization grid.

You can adjust list of scale factor with google-chrome using dev tools on page chrome://settings/?search=zoom Inspect page zoom chooser element with Developper tool. Look at zoomLevel list and copy/paste on element. Then change the value and print. It will be saved in ".config/google-chrome/default/Current Session" binary file.

On Mozilla Firefox you just have to go on about:config and get the list toolkit.zoomManager.zoomValues

1. Use debug option in web Connection form.

If you want to build your own TiledViz cases, you may read TVConnection/TVConnections.py because it contains initialization and functions for calling in case job.

This debug option may stop the connection script before you launch your own job then you can test it manualy.

You may use os.system('/cat_between #Line1 #Line2 file.py') to display and copy/paste parts of your script in the ipython prompt.

You can either have python sources of your functions already loaded with this command print(inspect.getsource(myfun)) on ipython prompt.

1. Problems on some OS

Some gvfs versions gives full memory with Connections docker and udisks2-volume-monitor service. You can deactivate this behaviour with

systemctl –user stop gvfs-udisks2-volume-monitor.service systemctl –user mask gvfs-udisks2-volume-monitor.service

Some new Dockerd version limit system in containers. This blocks connections to x11vnc server for TVConnection client. One must change /etc/docker/daemon.json by added

"default-ulimits": {
   "nofile": {
      "Hard": 1048576,
      "Name": "nofile",
      "Soft": 1048576
    }
}

1. SSL and server deployment

Give SERVER_NAME.DOMAIN web server string available in a DNS service. Give SSL public then private available keys complete path in server at install stage in a readable directory. Thoses variables are asked in the installation step on a web server.

1. Logger

Change level (from WARNING to DEBUG) interactively :

docker exec -u flaskusr -it flaskdock bash -c 'echo DEBUG > /tmp/logfifo'

Size of server log:

docker inspect –format='{{.LogPath}}' flaskdock | xargs sudo du -sh

1. ssh version Switch to ed25519.

As per the release notes for OpenSSH 7.6:

Refuse RSA keys <1024 bits in length and improve reporting for keys that do not meet this requirement.

So it's likely that the key you're trying to import is too short (weak). Your best bet is to generate a new key.