puppet-nodejs: Installing as non-root user does not work (access denied)

Affected Puppet, Ruby, OS and module versions/distributions

• Puppet: 4.8.0
• Ruby: 2.1.9p490
• Distribution: within Docker Centos 7 image
• Module version: latest

How to reproduce (e.g Puppet code you use)

nodejs::npm { "install ${service_name} npm packages as user ${service_user}":
		ensure => 'present',
		user => $service_user,
		source => "/home/${service_user}/${service_name}/src/static/package.json",
		target => "/home/${service_user}/${service_name}/src/static",
		require => Class['nodejs'],
	}

What are you seeing

The process is trying to access /root/.npm while it is running as a different user:

e.g. part of the log: npm ERR! { Error: EACCES: permission denied, mkdir '/root/.npm'

What behaviour did you expect instead

I expected that the process was not trying to use anything inside the root dir. When I run npm install in the source directory as that $service_user it works.

Output log

Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! addLocal Could not install /home/clariah/wp5_mediasuite/src/static/package.json
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! Linux 4.9.36-moby
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! argv "/usr/bin/node" "/usr/bin/npm" "install" "/home/clariah/wp5_mediasuite/src/static/package.json"
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! node v6.10.3
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! npm  v3.10.10
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! path /root/.npm
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! code EACCES
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! errno -13
Notice: /Stage[main]/Rd_infra_service::Implementation::Media_suite/Rd_infra_service::Resource::Service[wp5_mediasuite]/Rd_infra_service::Resource::Webclient[wp5_mediasuite]/Nodejs::Npm[install wp5_mediasuite npm packages as user clariah]/Exec[npm_install_install wp5_mediasuite npm packages as user clariah]/returns: npm ERR! syscall mkdir