Kubernetes Default Network Policy examples
Default Network Policies in Kubernetes help control the traffic flow between pods by defining a set of rules that specify how pods are allowed to communicate with each other.
Unless specifically overridden by another Network Policy, Default Network Policies are applicable to all pods, in contrast to normal Network Policies that explicitly permit or prohibit traffic.
The following examples let you change the default behavior in that namespace.
Deny all ingress traffic
To build a “default” ingress isolation policy for a namespace, construct a NetworkPolicy that chooses all pods but does not allow ingress traffic to those pods.
Deny all egress traffic
You can create a “default” egress isolation policy for a namespace by creating a NetworkPolicy that selects all pods but does not allow any egress traffic from those pods.
Allow all ingress traffic
With this policy in effect, no further policies can deny any inbound connections to those pods. This policy has no effect on isolation during egress from any pod.
Allow all egress traffic
If you want to allow all connections from all pods in a namespace, you can create a policy that explicitly allows all outgoing connections from pods in that namespace.
Deny all ingress and all egress traffic
By setting the following NetworkPolicy in a namespace, you may set up a “default” policy that blocks all incoming and outgoing traffic.
kubernetes Network Policlies
Everyone agrees that Kubernetes clusters are insecure by default. But the good news is that Kubernetes provides the tools to make that happen. In this article, we’re going to learn about one of the resources that K8s provides straight out of the box to help make your deployed apps more secure: Network policies.
A Kubernetes network policy specifies how pods can communicate with one another and other network endpoints in a Kubernetes cluster. Network policies provide fine-grained control over network traffic, allowing you to partition your network and secure your applications. They allow you to set incoming and outgoing traffic rules for pods and are implemented in the Kubernetes cluster using a CNI plugin like Calico or Weave Net.