For installation:
https://hub.docker.com/r/technoexpress/freepbx (https://hub.docker.com/r/technoexpress/freepbx)
I been using Obi for my business PBX system for a while.
My setup have a obi202 at home, all calls go to the FreePBX IVR, depending on number press, dispatches to me by 'follow me', having a 'ring group' forwarding to cell and extensions.
My office/shop is at a distance location with hotspot internet access only, FreePBX is housed within a dedicated server with https://www.nocix.net/dedicated/ (https://www.nocix.net/dedicated/) partitioned up with Xen and Cloudmin.
Run the FreePBX Container:
Use the following command to create and start the FreePBX container:
docker run -d --name freepbx -p 80:80 -p 443:443 -p 5060:5060/udp -p 5160:5160/udp -p 18000-18100:18000-18100/udp technoexpress/freepbx