Function getOnePodIP

network/plugins.go:277–315

(
	execer utilexec.Interface,
	nsenterPath, netnsPath, interfaceName, addrType string,
)

}

func getOnePodIP(
	execer utilexec.Interface,
	nsenterPath, netnsPath, interfaceName, addrType string,
) (net.IP, error) {
	// Try to retrieve ip inside container network namespace
	output, err := execer.Command(
		nsenterPath,
		fmt.Sprintf("--net=%s", netnsPath),
		"-F",
		"--",
		"ip",
		"-o",
		addrType,
		"addr",
		"show",
		"dev",
		interfaceName,
		"scope",
		"global",
	).CombinedOutput()
	if err != nil {
		return nil, fmt.Errorf("unexpected command output %s with error: %v", output, err)
	}

	lines := strings.Split(string(output), "\n")
	if len(lines) < 1 {
		return nil, fmt.Errorf("unexpected command output %s", output)
	}
	fields := strings.Fields(lines[0])
	if len(fields) < 4 {
		return nil, fmt.Errorf("unexpected address output %s ", lines[0])
	}
	ip, _, err := net.ParseCIDR(fields[3])
	if err != nil {
		return nil, fmt.Errorf("CNI failed to parse ip from output %s due to %v", output, err)
	}

	return ip, nil
}

// GetPodIP gets the IP of the pod by inspecting the network info inside the pod's network namespace.
// we are defaulting to v4 as primary