Network Plugins

In Hostman Kubernetes, you can use various CNI (Container Network Interface) plugins, such as Calico, Flannel, Kube-router, and Cilium. These plugins facilitate pod connectivity to the network, manage routing, and enforce network policies, ensuring reliable and secure application performance.

Each of these plugins offers its own approach to addressing networking challenges in Kubernetes. Calico is suitable for high-performance networks with advanced security policies, Flannel stands out for its simplicity and reliability for basic networking tasks, Kube-router focuses on high-performance routing, and Cilium provides deep integration with the Linux kernel and advanced security features.

Let's examine the characteristics of each plugin to help you choose the right solution.

Calico

Calico is a high-performance networking solution for Kubernetes that uses IP-based routing to ensure communication between pods and external networks.

How It Works

Calico uses BGP (Border Gateway Protocol) to exchange routes between cluster nodes. This allows each node to know where the pods are located and route packets directly, bypassing additional processing, which significantly improves performance.

Network Policies

One of the key advantages of Calico is its support for advanced network policies. These policies allow for the configuration of access control between pods at the network packet level, which is crucial for application security. For example, you can specify which pods are allowed to exchange data with each other.

Advantages

• High performance due to non-overlay routing.

• Scalability for large clusters.

• Support for advanced network policies for security.

Flannel

Flannel is a simple and lightweight network plugin used for creating overlay networks in Kubernetes.

How It Works

Flannel creates virtual networks using VXLAN or UDP protocols, allowing pods to communicate with each other. Each pod is assigned an IP address from a range reserved for the virtual network, and traffic is routed through tunnels between nodes.

Network Policies

Flannel does not provide advanced network policies like Calico and does not support BGP-based routing. This makes it less complex but suitable for simple networking scenarios, especially in small and medium clusters.

Advantages

• Easy setup and operation.

• Suitable for small clusters and cases where complex network policies are not required.

Kube-router

Kube-router is a lightweight plugin that focuses on Layer 3 routing with minimal latency.

How It Works

Kube-router uses BGP to route traffic between pods on different nodes. It also provides network policy and load balancing features. Kube-router replaces the standard Kubernetes network stack, reducing complexity and overhead in processing network traffic.

Network Policies

In addition to routing, Kube-router provides traffic control through network policies and load balancing for IPVS (IP Virtual Server).

Advantages

• High performance and low latency.

• Support for network policies and load balancing.

• Easy integration with clusters requiring high-performance routing.

Cilium

Cilium is a powerful plugin that uses eBPF (extended Berkeley Packet Filter) for monitoring and managing network traffic at the operating system kernel level.

How It Works

Cilium utilizes eBPF to perform network operations directly in the Linux kernel, allowing for filtering, analyzing, and controlling network traffic with high precision and minimal processing overhead. This capability provides deep visibility into network flows and supports complex network policies at the application level.

Network Policies

Cilium supports standard Kubernetes network policies as well as advanced security features, such as HTTP request filtering and API interaction control.

Advantages

• Support for deep traffic analysis and application-level security policies.

• High performance due to integration with eBPF.

• Scalability and the ability to implement complex network policies.