Method setupNetworkDevices

libcontainer/process_linux.go:1082–1103

setupNetworkDevices sets up and initializes any defined network interface inside the container.

()

// setupNetworkDevices sets up and initializes any defined network interface inside the container.
func (p *initProcess) setupNetworkDevices() error {
	// host network pods does not move network devices.
	if !p.config.Config.Namespaces.Contains(configs.NEWNET) {
		return nil
	}
	// the container init process has already joined the provided net namespace,
	// so we can use the process's net ns path directly.
	nsPath := fmt.Sprintf("/proc/%d/ns/net", p.pid())

	// If moving any of the network devices fails, we return an error immediately.
	// The runtime spec requires that the kernel handles moving back any devices
	// that were successfully moved before the failure occurred.
	// See: https://github.com/opencontainers/runtime-spec/blob/27cb0027fd92ef81eda1ea3a8153b8337f56d94a/config-linux.md#namespace-lifecycle-and-container-termination
	for name, netDevice := range p.config.Config.NetDevices {
		err := devChangeNetNamespace(name, nsPath, *netDevice)
		if err != nil {
			return fmt.Errorf("move netDevice %s to namespace %s: %w", name, nsPath, err)
		}
	}

	return nil
}

func pidGetFd(pid, srcFd int) (*os.File, error) {
	pidFd, err := unix.PidfdOpen(pid, 0)