I've done this with Redmine v3.4.x in the past, but I've heard that the same configuration settings no longer work with 4.x (I've not tested to confirm whether this is true or not).
In some deployments it might make sense to make Portus accessible through a Sub-URI. That is, to be able to prefix requests to Portus with a subdirectory. In non-passenger setups, this can be accomplished by setting the RAILS_RELATIVE_URL_ROOT environment variable. With this, you will be able to serve Portus from the specified subdirectory.
Perhaps that environment variable can be used to accomplish the same sub-URI deployments of Redmine 4.x?
I've done this with Redmine v3.4.x in the past, but I've heard that the same configuration settings no longer work with 4.x (I've not tested to confirm whether this is true or not).
While exploring Docker Registry web UIs, I came across this remark on http://port.us.org/docs/Configuring-Portus.html:
Perhaps that environment variable can be used to accomplish the same sub-URI deployments of Redmine 4.x?