安装环境

cat <<EOF | kind create cluster --name test --config -
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
networking:
  kubeProxyMode: iptables
  disableDefaultCNI: false
  ipFamily: ipv4
  apiServerAddress: 127.0.0.1
  apiServerPort: 0
  podSubnet: "10.16.0.0/16"
  serviceSubnet: "10.96.0.0/12"
kubeadmConfigPatches:
  - |
    kind: ClusterConfiguration
    metadata:
    name: config
    etcd:
      local:
        dataDir: "/root/etcd"
nodes:
  - role: control-plane
    image: kindest/node:v1.26.0
EOF

git clone https://github.com/intel/multus-cni.git && cd multus-cni
git checkout v4.0.0
kubectl create -f ./deployments/multus-daemonset.yml

cat <<EOF | kubectl create -f -
apiVersion: "k8s.cni.cncf.io/v1"
kind: NetworkAttachmentDefinition
metadata:
  name: kindnet
spec: 
  config: '{"cniVersion":"0.3.1","name":"kindnet","type":"ptp","ipMasq":false,"ipam":{"type":"host-local","dataDir":"/run/cni-ipam-state","routes":[{"dst":"0.0.0.0/0"}],"ranges":[[{"subnet":"10.16.1.0/24"}]]}}'
EOF

cat <<EOF | kubectl create -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deploy
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: nginx-deploy
  template:
    metadata:
      annotations:
        k8s.v1.cni.cncf.io/networks: '[{"name":"kindnet","interface":"eth100"}]'
      labels:
        app: nginx-deploy
    spec:
      containers:
        - name: nginx-deploy
          image: nginx:1.27.0
EOF

确认容器内存在eth100网卡。

源码分析

multus
pkg/multus/multus.go
CmdAdd函数
处理cni add请求

pkg/multus/multus.go
getIfname函数
获取cni网卡名称

pkg/k8sclient/k8sclient.go
parsePodNetworkAnnotation函数
delegate.IfnameRequest来自pod注解解析json。

pkg/types/types.go
结构体NetworkSelectionElement