I was testing Network Policy on play-with-k8s, but it seems not working.
Network Policy has prerequisites:

1. Kubernets 1.7
2. Network plugin supports Network Policy

and play-with-k8s

1. is based on Kuberntes 1.7
2. need to install Weave Net add-ons network plugin, which supports Network Policy

But Network Policy has no effect in play-with-k8s. Any recommendations? Thanks.