<plugin> ...
<executions><execution><!-- optional: you don't really need execution ids, but it looks nice in your build log. --><id>install node and npm</id><goals><goal>install-node-and-npm</goal></goals><!-- optional: default phase is "generate-resources" --><phase>generate-resources</phase></execution></executions><configuration><nodeVersion>v4.6.0</nodeVersion><!-- optional: with node version greater than 4.0.0 will use npm provided by node distribution --><npmVersion>2.15.9</npmVersion><!-- optional: where to download node and npm from. Defaults to https://nodejs.org/dist/ --><downloadRoot>http://myproxy.example.org/nodejs/</downloadRoot></configuration></plugin>