Cloud-based IDE for Docker-based projects?

I asked this question in a few different places and not just here. After several months there has been no complete answer, but I have gained a bit more information that I would like to pass along to anyone who stumbles upon the same issue.

1. Regarding Cloud9 and CodeAnywhere

When spinning up a new SSH workspace, you can specify not only the host, but also the root folder for the workspace. This means you can create multiple workspaces on a single VM and keep everything nice and separate.

There are a few caveats:

• In order to truly keep your workspaces separate, you must create a new user for each workspace. Otherwise someone in workspaceA can edit ../workspaceB/file
• All workspaces will share the same disk space, so it's possible for someone working in one workspace to fill up the hard drive and cause issues for all other workspaces
• There's no easy way to spin up new workspaces. You have to log into the VM as an administrative user, create a new user, create a directory for the workspace, assign permissions, then set up a new SSH workspace. It may be possible to automate a large portion of this, though

2. Regarding CodeAnywhere specifically

CodeAnywhere promised full Docker support in Q4 of 2018. I've been waiting and haven't seen it yet. Keep your fingers crossed.

3. An alternate service

Now in 2018 there are over 50 cloud-based IDEs. Everyone and their mother is making a "me too" business. So it stands to reason that at least one of them will work. While I haven't gone around trying them all, I did hear from someone that OpenShift supports Docker.