Basic support IntelliJ IDEA as a Che editor

Is your enhancement related to a problem? Please describe.

Che-theia is the default editor. We support alternative editors such as dirigible, desktop eclipse and code-server. But not IntelliJ.

Describe the solution you’d like

Add support for IntelliJ as an editor. IntelliJ would run in the browser. IntelliJ community edition should be used. These are the subtasks:

• publish the sidecar image of the intellij community + vnc
• publish a Red Hat based sidecar(fedora) image of the intellij community + vnc
• UBI-based Dockerfile for IntelliJ IDEA Che editor
  • initial investigation https://github.com/eclipse/che/issues/18031
  • CRW-compatible image CRW#1239
• add the editor in the plugin registry https://github.com/eclipse/che/issues/17979
• document how to use it and extend it: RHDEVDOCS#2161
  • How to create a workspace that uses intellij as editor
  • How to customize it:
    • Inject a license key
    • Configure a Floating License Server using JETBRAINS_LICENSE_SERVER env variable
    • Use a different version of intelliJ
  • Current limitations
• persistent settings across workspace restart https://github.com/eclipse/che/issues/17968
• idle timeout che/intellij plug-in (to avoid it gets idled, no need to track activity) https://github.com/eclipse/che/issues/17953
• clone projects on boot https://github.com/eclipse/che/issues/15973
• implement and run an end to end test https://github.com/eclipse/che/issues/18035
• handling Enter key in built-in terminal (solution provided in https://github.com/eclipse/che/issues/17790#issuecomment-698854133) or have preliminary preference set up on workspace startup https://github.com/eclipse/che/issues/17986

What is NOT included in this issue

A fully supported editor should also:

• describe the IDE configuration in a devfile (commands, plugins, runtime services)
• automatically inject users configs in the IDE (such as proxy, git, kubernetes settings)
• airgap support

But these features are not in this issue scope. We will create dedicated issues for that.

Describe alternatives you’ve considered

• [CURRENT CHOICE] Running a VNC client in the browser (such as novnc)
• Using https://www.webswing.org/
• Running an X11 client in the browser (such as xpra-htlm5)

Additional context

This is a feature provided by coder enterprise (this is the dockerfile).

@benoitf has provided PoC that uses webswing and that can be tried out with the following devfile or using docker locally docker run --rm -it -p 8080:8080 quay.io/fbenoit/webswing-intellij:20200904.

[vzhukovs]

I think, we can add additional item into description, to have a preliminary IDE configuration and set up specific options like https://github.com/eclipse/che/issues/17790#issuecomment-698854133. Because when workspace opens at first time, user has to configure this option to operate with terminal. //upd: updated the last item in the list

[benoitf]

source code of POC are there

• https://github.com/benoitf/che-intellij-editor-vnc
• https://github.com/benoitf/che-intellij-editor-xpra
• https://github.com/benoitf/che-intellij-editor-webswing

(with VNC I was able to use browser resizing and maximize widgets using a lightweight wm (here it’s fluxbox) where I can hide toolbar/workspaces, etc by default)