Changing project property in subproject

I’m using gradle 4.8 in a multi-project java build for automating builds and deployments and I’m stuck in a “property set” problem.
In the root project build.gradle I apply a script to all subprojects:

	apply plugin: 'myTasks'
	apply from: 'build-generic.gradle'

In my build-generic I set some properties with default values:

project.ext {
	serverDomain = 'core'
	serverDeployPath = '/opt/'+serverDomain+'/deploy/'

In myTasks plugin I define the deploy task:

	doLast {
		def archive = '/build/libs/'+archiveName
		def serverDeployPath ='serverDeployPath')
		project.copy { from archive into serverDeployPath }

The idea is to override some of there properties in the build.gradle of a subproject, i.e.:

ext {
	serverDomain = 'services'

But when I run the deploy task I alway get the file copied into /opt/core/deploy instead of /opt/services/deploy.
While I understand it does make sense, after reading, searching and experimenting I didn’t find how to comply with these points:

  • serverDomain and serverDeployPath have to be defined with default values
  • a subproject can redefine any of these properties
  • if a subproject redefine serverDomain, serverDeployPath have to change accordingly
  • redefining a property in a subproject have to be as simple as ext { prop = ‘value’ } (we have a lot of projects with script like that I change them all is not possible)

Is there a possibility to achieve what I want?
Thank in advance for every suggestion.