Kubernetes cluster network policies
Kubernetes network policies help configure network interchanges between groups of pods and network nodes. You can create network policies using the Kubernetes Network Policy API that sets rules for filtering traffic at the pod level. These rules determine which pods and services in a Kubernetes cluster can access each other.
To manage network policies, Managed Service for Kubernetes uses the Calico and Cilium controllers.
The Calico network controller uses the iptables rules while Cilium utilizes the eBPF technology.
Warning
You can enable network policies only when creating a cluster.
Integration with load balancers
Warning
Due to the Yandex Cloud architecture, you can't use loadBalancerSourceRanges in Managed Service for Kubernetes when setting up network policy controllers. To allow traffic via the Yandex Network Load Balancer or Yandex Application Load Balancer use NetworkPolicy.
For step-by-step instructions on how to set up access to an application using NetworkPolicy, see Granting access to an app running in a Kubernetes cluster.
Calico
Calico enables you to configure basic security policies for Kubernetes clusters.
Step-by-step configuration instructions are provided at Configuring the Calico network policy controller.
Cilium
Unlike Calico, the Cilium controller has broader capabilities and enables you to:
- Use the same subnet ranges for pods and services in different clusters.
- Create more functional network policies, for example, by filtering pod-to-pod traffic at the L7 application layer or using the DNS name of an external resource.
- Use the built-in Hubble tool to monitor network events.
In a Managed Service for Kubernetes cluster, Cilium operates in tunneling mode. This mode implements network connectivity for cluster objects based on VxLAN technology using Cilium CNI.
Cilium tunneling mode helps:
- Create clusters with overlapping IP addresses on the same network.
- Use an extended address range of up to
/8for pod and cluster services. - Create twice as many cluster nodes (as compared to Calico).
To be able to use tunnel mode, a service account requires the k8s.tunnelClusters.agent role.
Note
Tunneling mode is at the Preview stage.
Cluster requirements to enable network policies
To enable network policies in a Kubernetes cluster, sufficient resources in node groups are required. Using network policies requires additional memory and vCPU resources.
We recommend that you only enable your network policy controller in a cluster of at least two nodes.