While Pleroma FE is still in development, it can be run in parallel with a GNU Social classic + Qvitter installation.
Pleroma FE is a completely static js client that works using the same Statusnet API that mobile clients like Twidere use. It can be deployed anywhere, it doesn't need to run on the same server as the GS instance at all.
However, because of browser limitations, Pleroma FE needs either the correct CORS headers set on the GS server, or the GS servers /api endpoints re-routed to appear under the same domain (see the example).
Another option is to just drop the index.html into the GS root directory and rename it to pleroma.html, for example. It can then be accessed by visiting my.gs.server/pleroma.html. This requires the hash-routed build of Pleroma.
The build process at pipelines will leave behind the compiled client as build artifacts, which can be deployed as-is.
Method 1 - Renaming index.html
This method is the easiest to setup, but it will result in not-so-pretty urls.
Step by Step
Download the latest feature/hash-routed branch build zip at pipelines.
Unzip and rename dist/index.html to dist/pleroma.html
Copy the contents of the dist folder into the root GS folder.
That's it, Pleroma should now be accessible under my.gs.server/pleroma.html
Method 2 - Nginx forwarding
Step by Step (nginx, forwarding)
Download the latest development branch build zip at pipelines.
Copy the contents of the dist folder into the folder where you want to host Pleroma FE (/var/www/pleroma in the example).
Add the nginx config as in the example below. Adjust domains names of Pleroma domain (pleroma.heldscal.la) and GS domain (social.heldscal.la)