Support for Cross Namespace Network traffic

[devdattakulkarni]

In certain situations, there might be a need to break the Namespace boundary that KubePlus enforces on service instances. For example, consider a setup where there is a database that needs to be used by two application instances. The database will be registered as its own KubePlus service with its own Helm chart. The application will be packaged as a separate Helm chart. KubePlus will create an instance of the database in its namespace. The two application instances will be created in their own namespaces. But KubePlus will prevent communication between the application instances and the database instance because of the Network Policy that KubePlus by default sets up for each application instance.

Selectively allowing cross Namespace traffic will allow KubePlus to handle this scenario.

[devdattakulkarni]

This can be implemented with a kubectl plugin.

kubectl allow network traffic <to-instance> <from-instance>

E.g.:
kubectl allow network traffic db1 wp1

The plugin implementation will update the NetworkPolicy object in db1 Namespace to allow network traffic from wp1 Namespace.

[devdattakulkarni]

@SuyogShinde942 You can take a look at this one too, after the NetworkTraffic isolation verification issue is done.