* default to Debian bookworm
* use DEBIAN_VERSION instead of lsb_release; gosu is in Debian since buster
* update comments for FS_META_PACKAGE and exposed ports
* fix SHELL invocation so 'RUN' works as expected in downstream builds
See: https://docs.docker.com/engine/reference/builder/#shell
Updates for the docker configuration to allow for the following:
- Allow for bring in own configuration
- Exposes the Ports needed for non-docker networking
- Allows for mount /tmp to write out logs, etc to the host machine if
configured as so.
- Health check of the freeswitch service
tmancill
soroshsabz
Sergey Safarov
Richard Genthner
Brian West