rootUrlPathPrefix can be set via the Meteor environment variable ROOT_URL_PATH_PREFIX, so maybe you can leverage that environment variable to do what you want. That being said I have a feeling the boilerplate generator won’t allow you to use full hostnames in the ROOT_URL_PATH_PREFIX (since that could be a mess when used with ROOT_URL), but I haven’t dug into the code to find out. If you’re interested, you can likely find the answer in the Meteor webapp package.
I tried setting the ROOT_URL_PATH_PREFIX, and that didn’t work. So I looked into the meteor source and found that the ROOT_URL_PATH_PREFIX is driven from ROOT_URL, it takes the ROOT_URL.pathname. And I also tried setting the meteor_runtime_config.ROOT_URL_PATH_PREFIX at Meteor.startup, but there’s logic in the webapp_server app.use to check and make sure the prefix starts with “/”…lol, and it’s not a named method, so I don’t see a way to override that. I guess the road ends there.
Do you know if there’s a way to override the boilerplate file?