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Canvas issues: files download, RCE features
Hello all,
I've greatly appreciated access to complex apps that I don't have the skill to install myself. I have a new appreciation for this after having installed Canvas per Instructure's instructions. I did this in an attempt to work around a few issues I was having on the TKL Canvas appliance (v. 16.1). The TKL appliance is almost working for us, but not quite.
The first issue is that we can upload files into a course (or anywhere you can access the files page), but we can't preview or download them. After working through the installation process on my own on an Ubuntu Bionic VM, I got one step closer. This was the relevant info that got me there.
Note that the optional files_domain field is required if you plan to host user-uploaded files and wish to be secure, or if you want to allow custom Javascript in custom themes. files_domain must be a different hostname from the browser's perspective, even though it can be the same Apache server, and even the same IP address.
In domain.yml (var/www/canvas/config/), I changed the files_domain entry to a different hostname, and now I can get the file download dialog, but the file that is downloaded is empty.
Secondly (and this might be related?), we also can't add a watermark in Themes. I can upload it, but it won't show on the preview, and if I save the changes, nothing is different in the Theme.
Thirdly, in the new Rich Content Editor, I can't upload media (I get "Something went wrong. Cannot read property 'length' of undefined"), and I can't record video from within the editor. I tried this on their free-for-teachers hosted version, and it works as expected.
In case it helps, I have attached the last 2M worth of production.log.
Thanks in advance for your help!
Replies (2)
I'll work on this
Reply 1This sounds suspiciously like RCE API issues
Reply 2Do you have your server registered with a "proper" FQDN (fully qualified domain name)? Do you also have legitimate SSL/TLS certificates for that URL? (free Let's Encrypt ones are fine, but you need to have valid SSL/TLS certificates so that https://YOUR.CANVAS.DOMAIN resolves properly in your web browser.
If you are sure that that is all correct, then please open your web browser's "developer tools" and check for any javascript errors.
Please feel free to post the URL here if it's publicly available and I'll have a look myself if you want?
As for recording from within the editor, I could be wrong, but IIRC that feature is not available in the open source self hosted version. I vaguely recall that it apparently relies on some proprietary javascript which they do not have a licence to distribute (and are unwilling to document how you can download and install yourself). Although perhaps I'm getting confused with some thing else? There are definitely a few features that do fall into that category though...
Yes, the server is registered with both canvas.pilgrimcs.org and canvas-files.pilgrimcs.org, but the latter is not set up with a valid SSL/TLS cert, so I'll get that set up (I did bypass the warning in the browser, but maybe that doesn't work...). I'm wondering now as well if I have the virtual hosts file set up correctly for canvas-files. I've lost remote access to this server just now, but I'll work on this and see what happens.
RE: recording within the editor: that's a credible explanation. I'll see if getting the above issues resolved takes care of the upload issues, and go from there.
Thanks much for your prompt reply! I should have thought to post here before I spent a day building the Ubuntu Canvas server from scratch. :-(