csi/cni插件实现原理

https://github.com/containernetworking/cni/blob/master/libcni/api.go

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)
}

func (c *CNIConfig) addNetwork(ctx context.Context, name, cniVersion string, net *NetworkConfig, prevResult types.Result, rt *RuntimeConf) (types.Result, error) {
    c.ensureExec()
    pluginPath, err := c.exec.FindInPath(net.Network.Type, c.Path)
    if err != nil {
        return nil, err
    }

    newConf, err := buildOneConfig(name, cniVersion, net, prevResult, rt)
    if err != nil {
        return nil, err
    }

    return invoke.ExecPluginWithResult(ctx, pluginPath, newConf.Bytes, c.args("ADD", rt), c.exec)
}

invoke.ExecPluginWithResult(ctx, pluginPath, newConf.Bytes, c.args("ADD", rt), c.exec)

通过invoke看出类似java反射机制，可以实现动态调用，例如可以动态的传人参数，可以把方法参数化。可以参考https://www.cnblogs.com/Eason-S/p/5851078.html