@abernix: Thank you very much for your reply.
I tried several times but had no luck. 
After checking the docs, etc. and other code examples I thought it makes sense to put the method you mentioned into “server/main.js”, code is like this:
import {Meteor} from 'meteor/meteor';
Meteor.methods({
getCurrentGalaxyAppVersionId() {
console.log("#CUSTOMLOG# Your Galaxy version is " + process.env['GALAXY_APP_VERSION_ID']);
return process.env['GALAXY_APP_VERSION_ID'];
}
});
Above log statement works fine, by the way.
Additionally I placed the client code in “imports/ui/body.js”, as I want to call
the method from body.html file:
import { Meteor } from 'meteor/meteor';
import { Template } from 'meteor/templating';
[..]
Template.body.helpers({
getCurrentGalaxyAppVersionId: function () {
Meteor.call('getCurrentGalaxyAppVersionId');
}
});
Now body.html (yes, I use Blaze):
Galaxy Version: {{getCurrentGalaxyAppVersionId}}
What am I doing wrong? 

Thanks in advance!
Kind regards,
ffmit