概述

CNI从设计上是k8s最简单的接口，但是网络的实现是存储复杂的，CNI在被调用时也是比较特别，会在containerd创建容器的过程中被调用。

spec

containerd CNI

type CNI interface {
	// Setup setup the network for the namespace
	Setup(ctx context.Context, id string, path string, opts ...NamespaceOpts) (*Result, error)
	// SetupSerially sets up each of the network interfaces for the namespace in serial
	SetupSerially(ctx context.Context, id string, path string, opts ...NamespaceOpts) (*Result, error)
	// Remove tears down the network of the namespace.
	Remove(ctx context.Context, id string, path string, opts ...NamespaceOpts) error
	// Check checks if the network is still in desired state
	Check(ctx context.Context, id string, path string, opts ...NamespaceOpts) error
	// Load loads the cni network config
	Load(opts ...Opt) error
	// Status checks the status of the cni initialization
	Status() error
	// GetConfig returns a copy of the CNI plugin configurations as parsed by CNI
	GetConfig() *ConfigResult
}

containernetworking(CNI)

type CNI interface {
	AddNetworkList(ctx context.Context, net *NetworkConfigList, rt *RuntimeConf) (types.Result, error)
	CheckNetworkList(ctx context.Context, net *NetworkConfigList, rt *RuntimeConf) error
	DelNetworkList(ctx context.Context, net *NetworkConfigList, rt *RuntimeConf) error
	GetNetworkListCachedResult(net *NetworkConfigList, rt *RuntimeConf) (types.Result, error)
	GetNetworkListCachedConfig(net *NetworkConfigList, rt *RuntimeConf) ([]byte, *RuntimeConf, error)

	AddNetwork(ctx context.Context, net *NetworkConfig, rt *RuntimeConf) (types.Result, error)
	CheckNetwork(ctx context.Context, net *NetworkConfig, rt *RuntimeConf) error
	DelNetwork(ctx context.Context, net *NetworkConfig, rt *RuntimeConf) error
	GetNetworkCachedResult(net *NetworkConfig, rt *RuntimeConf) (types.Result, error)
	GetNetworkCachedConfig(net *NetworkConfig, rt *RuntimeConf) ([]byte, *RuntimeConf, error)

	ValidateNetworkList(ctx context.Context, net *NetworkConfigList) ([]string, error)
	ValidateNetwork(ctx context.Context, net *NetworkConfig) ([]string, error)
}

部署cni

部署CNI

按照CNI提供商部署

配置

cd /etc/cni/net.d
cat 10-mynet.conf

bin

cd /opt/cni
ls bin

kubelet

   --network-plugin=cni
   --cni-conf-dir=/etc/cni/net.d
   --cni-bin-dir=/opt/cni/bin

ref

spec

api