noVNC controller

[msquee]

This PR is for discussion about creating new controller for VNC sessions. VncController will be a replacement for the current method of accessing VNC sessions in Open OnDemand.

Current problems with the VNC viewer implementation:

• No automatic updates for @novnc/novnc. Client side noVNC updates are a manual process right now that involves pulling the release from https://github.com/novnc/noVNC/releases.
• No server side validation for actually what is a valid VNC session. Ideally, there is a new route created /vnc/$JOB_ID and we can use $JOB_ID to validate the request before the VNC viewer is displayed.
• The password for the VNC session is passed as a URL query parameter (insecure). This should be rendered into the DOM server side and then RFB.js will create the connection client side.
• If the password for the VNC session changes, the user has to interrupt their workflow by going to My Interactive Sessions > VNC Session and completely reconnect.

Features to keep:

• Custom Ruby ERB information views (Windows, Linux, MacOS) for native VNC sessions https://sourcegraph.com/github.com/OSC/ondemand/-/blob/apps/dashboard/app/views/batch_connect/sessions/connections/_native_vnc.html.erb

New Features:

• Create new VNC sessions from this new controller interface.
• A "tab" like functionality to switch inline to multiple different sessions without leaving the browser window.

Resources: RFB.js (noVNC API) https://novnc.com/noVNC/docs/API.html

The novnc_link function is responsible for building the link to redirect the user to the noVNC session: https://sourcegraph.com/github.com/OSC/ondemand/-/blob/apps/dashboard/app/helpers/batch_connect/sessions_helper.rb?L179

┆Issue is synchronized with this Asana task by Unito

[johrstrom]

I put some work into this in this branch https://github.com/OSC/ondemand/tree/feature/no-vnc-yarn

There are some glaring issues:

• sharable links. We don't really want to pass the password in query parameters, but to make a sharable link work, I think we'd need to. Unless there's something else I'm missing.
• Layouts. The main layout defaults to md-4. Because I enabled this into batch_connet/sessions#show it uses that layout. Changing the layout_container_class would affect other batch connect views (like #index and #new).