The working directory should be /opt/phabricator to ease daily operations.

Case use

Currently, to call a Phabricator maintenance command being sure it's in relative path paradigm, we need to login, then run the command:

$ shell devcentral
$ cd /opt/phabricator
$ bin/storage upgrade

Ideally, default Docker container path should be /opt/phabricator, so we could only do:

$ shell devcentral bin/storage upgrade

Solution offered

Add to Dockerfile a WORKDIR /opt/phabricator directive.