In this post, you use Docker to pull and run the SQL Server 2017 container image in Ubuntu 18.04 LXD containers. This post contains a fix for ZFS on Linux with SQL Server 2017.
Collabora Online supports editing your documents in real time with multiple other editors, showing high fidelity, WYSIWYG rendering and preserving the layout and formatting of your documents. My recommendation is to integrate Collabora Online with Nextcloud.
App containers like Docker are vulnerable to security risks. Docker inside an OpenVZ container is a nice solution to secure your containers!
I will explain how to configure Docker inside a container with CentOS 7.