dendron: Markdown Preview never renders with `code-server`

Please select the area your bug applies to. (Multiple selections are Possible. You can leave blank if you’re not sure.)

Workspace. VSCode workspace, vaults, Intellisense/autocomplete, Dendron settings
Lookup. Dendron’s Lookup Command
Views. Dendron Preview, Tree View, Side Panels in the UI
Schema. Dendron Schemas
Pod. Data import from / export to Dendron
Publish. External Site Publish
Markdown. Markdown features, such as syntax support and features

Describe the bug

Remoting into a dendron workspace on a raspberry pi with vs code server activates dendron, but the markdown preview fails to load, stuck on Loading...

To Reproduce

Steps to reproduce the behavior:

Install vscode server on a raspberry pi.
Install dendron extension and set up dendron workspace.
Use another computer to Remote-SSH into the dendron workspace.
Lookup root.
Click Show Preview.

Expected behavior

The note to render in the side pane, but after the pane opens it never gets past the loading text.

Screenshots

Bug on the local machine Code_0cOjAB6qqc

Extension Runtime Status Error on the local machine Code_Zvy2KRwINi

Extension Runtime Status Error on the remote machine dendron

Desktop (please complete the following information)

OS:
- Local: Windows 10
- Remote: Raspberry Pi OS 32bit
Browser: NA
Version: Dendron version 0.75.0

Additional context

The preview works as expected when using vscode on the pi locally, just not over ssh remotely. I have removed the markdown enhanced dendron extension and the problem didn’t change.

Dendron Log file

dendron.log

About this issue

Original URL
State: closed
Created 3 years ago
Reactions: 1
Comments: 15 (7 by maintainers)

Most upvoted comments

I think this is a port forwarding issue between the local and remote machines. I’m not super familiar with the codebase, but it looks like the main Dendron API server is launched with a random port (since the code is effectively calling server.listen with port=0 unless engineServerPort is specified in the config file). If this random port is not forwarded to the local machine, then the markdown preview (and possibly other things?) won’t work.

This port is automatically forwarded when opening the calendar view, or when opening the configuration page, since the vscode.env.asExternalUri function is called in both cases (see https://code.visualstudio.com/api/advanced-topics/remote-extensions#forwarding-localhost).

This port is not automatically forwarded when opening the preview panel. I think this is because WebViewUtils.getWebviewContent is called, rather than WebViewUtils.genHTMLForView, and the vscode.env.asExternalUri is not called in this code path.

Finally, vscode remembers workspace port forwarding rules by default, but this doesn’t help if a random port is chosen each time.

Unless there is a vscode API for controlling port forwards, one way this could be fixed is by calling vscode.env.asExternalUri once the sever has started.

opcon on Feb 10, 2022

I’m having this issue, except I don’t see any errors logged. I also found a way to get the preview working (in my case at least).

When I click the Calender View pane in VSCode to expand, it seems to start a web server for the calendar. The preview then renders after re-opening it and works consistently as long as I leave the Calendar View pane expanded. It keeps working across reloads and restarts too as long as the Calendar View remains expanded.

neodon on Dec 30, 2021