There is no absolute “best” choice of CNI (Container Network Interface) plugin for Kubernetes (K8s), as different plugins are suitable for different scenarios and requirements. Here are some common CNI plugins and their features, as well as factors you might consider when choosing them:
1. Flannel
Features:
- One of the most commonly used K8s network plugins.
- Uses virtual network technologies (such as VXLAN, UDP, and Host-GW) to enable communication between containers.
- Supports a wide range of network backends and is easy to deploy and configure.
Usage Scenarios:
- Suitable for most basic network communication needs.
- Especially in environments that do not require complex network policies or advanced network features.
2. Calico
Features:
- BGP-based network plug-in.
- Uses routing tables to route traffic between containers and supports multiple network topologies.
- Provides security and network policy features.
Usage Scenarios:
- Scenarios that require advanced network policy and security.
- Cross-cluster communication or when more complex network routing is required.
3. Canal
Features:
- Canal is a combination of Flannel and Calico.
- It uses Flannel to provide inter-container communication and Calico to provide network policy and security features.
Usage Scenario:
- Need both the simplicity and ease of use of Flannel, but also need to Calico network policy and security scenarios.
4. Weave Net
Features:
- Lightweight network plug-in.
- Uses virtual network technology to provide IP addresses for containers and supports a variety of network backends (such as VXLAN, UDP, and TCP/IP).
- Provides network policy and security features.
Usage Scenario:
- Scenarios that require a lightweight and full-featured network plugin.
- Especially in dynamic environments or when rapid deployment is required.
5. Cilium
Features:
- Network plug-in based on eBPF (Extended Berkeley Packet Filter) technology.
- Uses a dynamic plug-in for the Linux kernel to provide network features such as routing, load balancing, security, and network policies.
Usage Scenario:
- Scenarios that require highly customizable and high-performance network functions.
- Especially when deep control of network traffic and security policies is required.
6. Contiv
Features:
- Network plug-in based on SDN (Software-Defined Networking) technology.
- Provides a variety of network functions such as virtual networks, network isolation, load balancing, and security policies.
Usage Scenario:
- Scenarios that require comprehensive and powerful network functions.
- Especially when building complex network architectures.
7. Antrea
Features:
- Network plug-in based on OVS (Open vSwitch) technology.
- Provides features such as communication between containers, network policies, and security.
- Supports multiple network topologies.
Usage Scenario:
- Scenarios that require network plug-ins based on OVS technology.
- Especially in network environments that require high performance and scalability.
Why choose a specific plug-in?
The following factors should be considered when selecting a specific CNI plug-in:
- Network requirements: Select the plug-in based on the cluster's network requirements (e.g., performance, security, policy, etc.).
- Ease of use: How easy it is to deploy, configure, and maintain the plug-in.
- Compatibility: the plug-in's compatibility with the Kubernetes version and its ability to integrate with other cluster components.
- Community support: The plug-in's community activity, documentation, and speed of problem resolution.
- Cost: the open source nature of the plugin, whether it requires a commercial license or additional costs.
In summary, no CNI plug-in is absolutely optimal, and the choice depends on specific network requirements, scenarios and preferences. When making a choice, it is recommended to consider the above factors and conduct proper testing and evaluation.