k3s/pkg/agent/config/config.go
Jamie Phillips 7345ac35ae
Initial windows support for agent (#3375)
Signed-off-by: Jamie Phillips <jamie.phillips@suse.com>
2021-06-01 12:29:46 -07:00

608 lines
21 KiB
Go

package config
import (
"bufio"
"context"
cryptorand "crypto/rand"
"crypto/tls"
"encoding/hex"
"encoding/pem"
"fmt"
"io/ioutil"
sysnet "net"
"net/http"
"net/url"
"os"
"os/exec"
"path/filepath"
"regexp"
"strings"
"time"
"github.com/pkg/errors"
"github.com/rancher/k3s/pkg/agent/proxy"
"github.com/rancher/k3s/pkg/cli/cmds"
"github.com/rancher/k3s/pkg/clientaccess"
"github.com/rancher/k3s/pkg/containerd"
"github.com/rancher/k3s/pkg/daemons/config"
"github.com/rancher/k3s/pkg/daemons/control/deps"
"github.com/rancher/k3s/pkg/util"
"github.com/rancher/k3s/pkg/version"
"github.com/rancher/wrangler/pkg/slice"
"github.com/sirupsen/logrus"
"k8s.io/apimachinery/pkg/util/json"
"k8s.io/apimachinery/pkg/util/net"
)
const (
DefaultPodManifestPath = "pod-manifests"
)
func Get(ctx context.Context, agent cmds.Agent, proxy proxy.Proxy) *config.Node {
for {
agentConfig, err := get(ctx, &agent, proxy)
if err != nil {
logrus.Errorf("Failed to configure agent: %v", err)
select {
case <-time.After(5 * time.Second):
continue
case <-ctx.Done():
logrus.Fatalf("Interrupted")
}
}
return agentConfig
}
}
type HTTPRequester func(u string, client *http.Client, username, password string) ([]byte, error)
func Request(path string, info *clientaccess.Info, requester HTTPRequester) ([]byte, error) {
u, err := url.Parse(info.BaseURL)
if err != nil {
return nil, err
}
u.Path = path
return requester(u.String(), clientaccess.GetHTTPClient(info.CACerts), info.Username, info.Password)
}
func getNodeNamedCrt(nodeName string, nodeIPs []sysnet.IP, nodePasswordFile string) HTTPRequester {
return func(u string, client *http.Client, username, password string) ([]byte, error) {
req, err := http.NewRequest(http.MethodGet, u, nil)
if err != nil {
return nil, err
}
if username != "" {
req.SetBasicAuth(username, password)
}
req.Header.Set(version.Program+"-Node-Name", nodeName)
nodePassword, err := ensureNodePassword(nodePasswordFile)
if err != nil {
return nil, err
}
req.Header.Set(version.Program+"-Node-Password", nodePassword)
req.Header.Set(version.Program+"-Node-IP", util.JoinIPs(nodeIPs))
resp, err := client.Do(req)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode == http.StatusForbidden {
return nil, fmt.Errorf("Node password rejected, duplicate hostname or contents of '%s' may not match server node-passwd entry, try enabling a unique node name with the --with-node-id flag", nodePasswordFile)
}
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("%s: %s", u, resp.Status)
}
return ioutil.ReadAll(resp.Body)
}
}
func ensureNodeID(nodeIDFile string) (string, error) {
if _, err := os.Stat(nodeIDFile); err == nil {
id, err := ioutil.ReadFile(nodeIDFile)
return strings.TrimSpace(string(id)), err
}
id := make([]byte, 4, 4)
_, err := cryptorand.Read(id)
if err != nil {
return "", err
}
nodeID := hex.EncodeToString(id)
return nodeID, ioutil.WriteFile(nodeIDFile, []byte(nodeID+"\n"), 0644)
}
func ensureNodePassword(nodePasswordFile string) (string, error) {
if _, err := os.Stat(nodePasswordFile); err == nil {
password, err := ioutil.ReadFile(nodePasswordFile)
return strings.TrimSpace(string(password)), err
}
password := make([]byte, 16, 16)
_, err := cryptorand.Read(password)
if err != nil {
return "", err
}
nodePassword := hex.EncodeToString(password)
return nodePassword, ioutil.WriteFile(nodePasswordFile, []byte(nodePassword+"\n"), 0600)
}
func upgradeOldNodePasswordPath(oldNodePasswordFile, newNodePasswordFile string) {
password, err := ioutil.ReadFile(oldNodePasswordFile)
if err != nil {
return
}
if err := ioutil.WriteFile(newNodePasswordFile, password, 0600); err != nil {
logrus.Warnf("Unable to write password file: %v", err)
return
}
if err := os.Remove(oldNodePasswordFile); err != nil {
logrus.Warnf("Unable to remove old password file: %v", err)
return
}
}
func getServingCert(nodeName string, nodeIPs []sysnet.IP, servingCertFile, servingKeyFile, nodePasswordFile string, info *clientaccess.Info) (*tls.Certificate, error) {
servingCert, err := Request("/v1-"+version.Program+"/serving-kubelet.crt", info, getNodeNamedCrt(nodeName, nodeIPs, nodePasswordFile))
if err != nil {
return nil, err
}
servingCert, servingKey := splitCertKeyPEM(servingCert)
if err := ioutil.WriteFile(servingCertFile, servingCert, 0600); err != nil {
return nil, errors.Wrapf(err, "failed to write node cert")
}
if err := ioutil.WriteFile(servingKeyFile, servingKey, 0600); err != nil {
return nil, errors.Wrapf(err, "failed to write node key")
}
cert, err := tls.X509KeyPair(servingCert, servingKey)
if err != nil {
return nil, err
}
return &cert, nil
}
func getHostFile(filename, keyFile string, info *clientaccess.Info) error {
basename := filepath.Base(filename)
fileBytes, err := info.Get("/v1-" + version.Program + "/" + basename)
if err != nil {
return err
}
if keyFile == "" {
if err := ioutil.WriteFile(filename, fileBytes, 0600); err != nil {
return errors.Wrapf(err, "failed to write cert %s", filename)
}
} else {
fileBytes, keyBytes := splitCertKeyPEM(fileBytes)
if err := ioutil.WriteFile(filename, fileBytes, 0600); err != nil {
return errors.Wrapf(err, "failed to write cert %s", filename)
}
if err := ioutil.WriteFile(keyFile, keyBytes, 0600); err != nil {
return errors.Wrapf(err, "failed to write key %s", filename)
}
}
return nil
}
func splitCertKeyPEM(bytes []byte) (certPem []byte, keyPem []byte) {
for {
b, rest := pem.Decode(bytes)
if b == nil {
break
}
bytes = rest
if strings.Contains(b.Type, "PRIVATE KEY") {
keyPem = append(keyPem, pem.EncodeToMemory(b)...)
} else {
certPem = append(certPem, pem.EncodeToMemory(b)...)
}
}
return
}
func getNodeNamedHostFile(filename, keyFile, nodeName string, nodeIPs []sysnet.IP, nodePasswordFile string, info *clientaccess.Info) error {
basename := filepath.Base(filename)
fileBytes, err := Request("/v1-"+version.Program+"/"+basename, info, getNodeNamedCrt(nodeName, nodeIPs, nodePasswordFile))
if err != nil {
return err
}
fileBytes, keyBytes := splitCertKeyPEM(fileBytes)
if err := ioutil.WriteFile(filename, fileBytes, 0600); err != nil {
return errors.Wrapf(err, "failed to write cert %s", filename)
}
if err := ioutil.WriteFile(keyFile, keyBytes, 0600); err != nil {
return errors.Wrapf(err, "failed to write key %s", filename)
}
return nil
}
func getHostnameAndIPs(info cmds.Agent) (string, []sysnet.IP, error) {
ips := []sysnet.IP{}
if len(info.NodeIP) == 0 {
hostIP, err := net.ChooseHostInterface()
if err != nil {
return "", nil, err
}
ips = append(ips, hostIP)
} else {
for _, hostIP := range info.NodeIP {
for _, v := range strings.Split(hostIP, ",") {
ip := sysnet.ParseIP(v)
if ip == nil {
return "", nil, fmt.Errorf("invalid node-ip %s", v)
}
ips = append(ips, ip)
}
}
}
name := info.NodeName
if name == "" {
hostname, err := os.Hostname()
if err != nil {
return "", nil, err
}
name = hostname
}
// Use lower case hostname to comply with kubernetes constraint:
// https://github.com/kubernetes/kubernetes/issues/71140
name = strings.ToLower(name)
return name, ips, nil
}
func isValidResolvConf(resolvConfFile string) bool {
file, err := os.Open(resolvConfFile)
if err != nil {
return false
}
defer file.Close()
nameserver := regexp.MustCompile(`^nameserver\s+([^\s]*)`)
scanner := bufio.NewScanner(file)
for scanner.Scan() {
ipMatch := nameserver.FindStringSubmatch(scanner.Text())
if len(ipMatch) == 2 {
ip := sysnet.ParseIP(ipMatch[1])
if ip == nil || !ip.IsGlobalUnicast() {
return false
}
}
}
if err := scanner.Err(); err != nil {
return false
}
return true
}
func locateOrGenerateResolvConf(envInfo *cmds.Agent) string {
if envInfo.ResolvConf != "" {
return envInfo.ResolvConf
}
resolvConfs := []string{"/etc/resolv.conf", "/run/systemd/resolve/resolv.conf"}
for _, conf := range resolvConfs {
if isValidResolvConf(conf) {
return conf
}
}
tmpConf := filepath.Join(os.TempDir(), version.Program+"-resolv.conf")
if err := ioutil.WriteFile(tmpConf, []byte("nameserver 8.8.8.8\n"), 0444); err != nil {
logrus.Errorf("Failed to write %s: %v", tmpConf, err)
return ""
}
return tmpConf
}
func get(ctx context.Context, envInfo *cmds.Agent, proxy proxy.Proxy) (*config.Node, error) {
if envInfo.Debug {
logrus.SetLevel(logrus.DebugLevel)
}
info, err := clientaccess.ParseAndValidateToken(proxy.SupervisorURL(), envInfo.Token)
if err != nil {
return nil, err
}
controlConfig, err := getConfig(info)
if err != nil {
return nil, errors.Wrap(err, "failed to retrieve configuration from server")
}
// If the supervisor and externally-facing apiserver are not on the same port, tell the proxy where to find the apiserver.
if controlConfig.SupervisorPort != controlConfig.HTTPSPort {
if err := proxy.SetAPIServerPort(ctx, controlConfig.HTTPSPort); err != nil {
return nil, errors.Wrapf(err, "failed to setup access to API Server port %d on at %s", controlConfig.HTTPSPort, proxy.SupervisorURL())
}
}
var flannelIface *sysnet.Interface
if !envInfo.NoFlannel && len(envInfo.FlannelIface) > 0 {
flannelIface, err = sysnet.InterfaceByName(envInfo.FlannelIface)
if err != nil {
return nil, errors.Wrapf(err, "unable to find interface")
}
}
clientCAFile := filepath.Join(envInfo.DataDir, "agent", "client-ca.crt")
if err := getHostFile(clientCAFile, "", info); err != nil {
return nil, err
}
serverCAFile := filepath.Join(envInfo.DataDir, "agent", "server-ca.crt")
if err := getHostFile(serverCAFile, "", info); err != nil {
return nil, err
}
servingKubeletCert := filepath.Join(envInfo.DataDir, "agent", "serving-kubelet.crt")
servingKubeletKey := filepath.Join(envInfo.DataDir, "agent", "serving-kubelet.key")
nodePasswordRoot := "/"
if envInfo.Rootless {
nodePasswordRoot = filepath.Join(envInfo.DataDir, "agent")
}
nodeConfigPath := filepath.Join(nodePasswordRoot, "etc", "rancher", "node")
if err := os.MkdirAll(nodeConfigPath, 0755); err != nil {
return nil, err
}
oldNodePasswordFile := filepath.Join(envInfo.DataDir, "agent", "node-password.txt")
newNodePasswordFile := filepath.Join(nodeConfigPath, "password")
upgradeOldNodePasswordPath(oldNodePasswordFile, newNodePasswordFile)
nodeName, nodeIPs, err := getHostnameAndIPs(*envInfo)
if err != nil {
return nil, err
}
if envInfo.WithNodeID {
nodeID, err := ensureNodeID(filepath.Join(nodeConfigPath, "id"))
if err != nil {
return nil, err
}
nodeName += "-" + nodeID
}
os.Setenv("NODE_NAME", nodeName)
servingCert, err := getServingCert(nodeName, nodeIPs, servingKubeletCert, servingKubeletKey, newNodePasswordFile, info)
if err != nil {
return nil, err
}
clientKubeletCert := filepath.Join(envInfo.DataDir, "agent", "client-kubelet.crt")
clientKubeletKey := filepath.Join(envInfo.DataDir, "agent", "client-kubelet.key")
if err := getNodeNamedHostFile(clientKubeletCert, clientKubeletKey, nodeName, nodeIPs, newNodePasswordFile, info); err != nil {
return nil, err
}
kubeconfigKubelet := filepath.Join(envInfo.DataDir, "agent", "kubelet.kubeconfig")
if err := deps.KubeConfig(kubeconfigKubelet, proxy.APIServerURL(), serverCAFile, clientKubeletCert, clientKubeletKey); err != nil {
return nil, err
}
clientKubeProxyCert := filepath.Join(envInfo.DataDir, "agent", "client-kube-proxy.crt")
clientKubeProxyKey := filepath.Join(envInfo.DataDir, "agent", "client-kube-proxy.key")
if err := getHostFile(clientKubeProxyCert, clientKubeProxyKey, info); err != nil {
return nil, err
}
kubeconfigKubeproxy := filepath.Join(envInfo.DataDir, "agent", "kubeproxy.kubeconfig")
if err := deps.KubeConfig(kubeconfigKubeproxy, proxy.APIServerURL(), serverCAFile, clientKubeProxyCert, clientKubeProxyKey); err != nil {
return nil, err
}
clientK3sControllerCert := filepath.Join(envInfo.DataDir, "agent", "client-"+version.Program+"-controller.crt")
clientK3sControllerKey := filepath.Join(envInfo.DataDir, "agent", "client-"+version.Program+"-controller.key")
if err := getHostFile(clientK3sControllerCert, clientK3sControllerKey, info); err != nil {
return nil, err
}
kubeconfigK3sController := filepath.Join(envInfo.DataDir, "agent", version.Program+"controller.kubeconfig")
if err := deps.KubeConfig(kubeconfigK3sController, proxy.APIServerURL(), serverCAFile, clientK3sControllerCert, clientK3sControllerKey); err != nil {
return nil, err
}
nodeConfig := &config.Node{
Docker: envInfo.Docker,
SELinux: envInfo.EnableSELinux,
ContainerRuntimeEndpoint: envInfo.ContainerRuntimeEndpoint,
FlannelBackend: controlConfig.FlannelBackend,
ServerHTTPSPort: controlConfig.HTTPSPort,
}
nodeConfig.FlannelIface = flannelIface
nodeConfig.Images = filepath.Join(envInfo.DataDir, "agent", "images")
nodeConfig.AgentConfig.NodeName = nodeName
nodeConfig.AgentConfig.NodeConfigPath = nodeConfigPath
nodeConfig.AgentConfig.ServingKubeletCert = servingKubeletCert
nodeConfig.AgentConfig.ServingKubeletKey = servingKubeletKey
nodeConfig.AgentConfig.ClusterDNS = controlConfig.ClusterDNS
nodeConfig.AgentConfig.ClusterDomain = controlConfig.ClusterDomain
nodeConfig.AgentConfig.ResolvConf = locateOrGenerateResolvConf(envInfo)
nodeConfig.AgentConfig.ClientCA = clientCAFile
nodeConfig.AgentConfig.ListenAddress = "0.0.0.0"
nodeConfig.AgentConfig.KubeConfigKubelet = kubeconfigKubelet
nodeConfig.AgentConfig.KubeConfigKubeProxy = kubeconfigKubeproxy
nodeConfig.AgentConfig.KubeConfigK3sController = kubeconfigK3sController
if envInfo.Rootless {
nodeConfig.AgentConfig.RootDir = filepath.Join(envInfo.DataDir, "agent", "kubelet")
}
nodeConfig.AgentConfig.Snapshotter = envInfo.Snapshotter
nodeConfig.AgentConfig.IPSECPSK = controlConfig.IPSECPSK
nodeConfig.AgentConfig.StrongSwanDir = filepath.Join(envInfo.DataDir, "agent", "strongswan")
nodeConfig.CACerts = info.CACerts
nodeConfig.Containerd.Config = filepath.Join(envInfo.DataDir, "agent", "etc", "containerd", "config.toml")
nodeConfig.Containerd.Root = filepath.Join(envInfo.DataDir, "agent", "containerd")
if !nodeConfig.Docker && nodeConfig.ContainerRuntimeEndpoint == "" {
switch nodeConfig.AgentConfig.Snapshotter {
case "overlayfs":
if err := containerd.OverlaySupported(nodeConfig.Containerd.Root); err != nil {
return nil, errors.Wrapf(err, "\"overlayfs\" snapshotter cannot be enabled for %q, try using \"fuse-overlayfs\" or \"native\"",
nodeConfig.Containerd.Root)
}
case "fuse-overlayfs":
if err := containerd.FuseoverlayfsSupported(nodeConfig.Containerd.Root); err != nil {
return nil, errors.Wrapf(err, "\"fuse-overlayfs\" snapshotter cannot be enabled for %q, try using \"native\"",
nodeConfig.Containerd.Root)
}
}
}
nodeConfig.Containerd.Opt = filepath.Join(envInfo.DataDir, "agent", "containerd")
if !envInfo.Debug {
nodeConfig.Containerd.Log = filepath.Join(envInfo.DataDir, "agent", "containerd", "containerd.log")
}
nodeConfig.Containerd.State = "/run/k3s/containerd"
nodeConfig.Containerd.Address = filepath.Join(nodeConfig.Containerd.State, "containerd.sock")
nodeConfig.Containerd.Template = filepath.Join(envInfo.DataDir, "agent", "etc", "containerd", "config.toml.tmpl")
nodeConfig.Certificate = servingCert
nodeConfig.AgentConfig.NodeIPs = nodeIPs
nodeIP, err := util.GetFirst4(nodeIPs)
if err != nil {
return nil, errors.Wrap(err, "cannot configure IPv4 node-ip")
}
nodeConfig.AgentConfig.NodeIP = nodeIP.String()
for _, externalIP := range envInfo.NodeExternalIP {
for _, v := range strings.Split(externalIP, ",") {
ip := sysnet.ParseIP(v)
if ip == nil {
return nil, fmt.Errorf("invalid node-external-ip %s", v)
}
nodeConfig.AgentConfig.NodeExternalIPs = append(nodeConfig.AgentConfig.NodeExternalIPs, ip)
}
}
// if configured, set NodeExternalIP to the first IPv4 address, for legacy clients
if len(nodeConfig.AgentConfig.NodeExternalIPs) > 0 {
nodeExternalIP, err := util.GetFirst4(nodeConfig.AgentConfig.NodeExternalIPs)
if err != nil {
return nil, errors.Wrap(err, "cannot configure IPv4 node-external-ip")
}
nodeConfig.AgentConfig.NodeExternalIP = nodeExternalIP.String()
}
if nodeConfig.FlannelBackend == config.FlannelBackendNone {
nodeConfig.NoFlannel = true
} else {
nodeConfig.NoFlannel = envInfo.NoFlannel
}
if !nodeConfig.NoFlannel {
hostLocal, err := exec.LookPath("host-local")
if err != nil {
return nil, errors.Wrapf(err, "failed to find host-local")
}
if envInfo.FlannelConf == "" {
nodeConfig.FlannelConf = filepath.Join(envInfo.DataDir, "agent", "etc", "flannel", "net-conf.json")
} else {
nodeConfig.FlannelConf = envInfo.FlannelConf
nodeConfig.FlannelConfOverride = true
}
nodeConfig.AgentConfig.CNIBinDir = filepath.Dir(hostLocal)
nodeConfig.AgentConfig.CNIConfDir = filepath.Join(envInfo.DataDir, "agent", "etc", "cni", "net.d")
}
if !nodeConfig.Docker && nodeConfig.ContainerRuntimeEndpoint == "" {
nodeConfig.AgentConfig.RuntimeSocket = nodeConfig.Containerd.Address
} else {
nodeConfig.AgentConfig.RuntimeSocket = nodeConfig.ContainerRuntimeEndpoint
nodeConfig.AgentConfig.CNIPlugin = true
}
if controlConfig.ClusterIPRange != nil {
nodeConfig.AgentConfig.ClusterCIDR = controlConfig.ClusterIPRange
nodeConfig.AgentConfig.ClusterCIDRs = []*sysnet.IPNet{controlConfig.ClusterIPRange}
}
if len(controlConfig.ClusterIPRanges) > 0 {
nodeConfig.AgentConfig.ClusterCIDRs = controlConfig.ClusterIPRanges
}
if controlConfig.ServiceIPRange != nil {
nodeConfig.AgentConfig.ServiceCIDR = controlConfig.ServiceIPRange
nodeConfig.AgentConfig.ServiceCIDRs = []*sysnet.IPNet{controlConfig.ServiceIPRange}
}
if len(controlConfig.ServiceIPRanges) > 0 {
nodeConfig.AgentConfig.ServiceCIDRs = controlConfig.ServiceIPRanges
}
if controlConfig.ServiceNodePortRange != nil {
nodeConfig.AgentConfig.ServiceNodePortRange = *controlConfig.ServiceNodePortRange
}
if len(controlConfig.ClusterDNSs) == 0 {
nodeConfig.AgentConfig.ClusterDNSs = []sysnet.IP{controlConfig.ClusterDNS}
} else {
nodeConfig.AgentConfig.ClusterDNSs = controlConfig.ClusterDNSs
}
nodeConfig.AgentConfig.PauseImage = envInfo.PauseImage
nodeConfig.AgentConfig.AirgapExtraRegistry = envInfo.AirgapExtraRegistry
nodeConfig.AgentConfig.SystemDefaultRegistry = controlConfig.SystemDefaultRegistry
// Apply SystemDefaultRegistry to PauseImage and AirgapExtraRegistry
if controlConfig.SystemDefaultRegistry != "" {
if nodeConfig.AgentConfig.PauseImage != "" && !strings.HasPrefix(nodeConfig.AgentConfig.PauseImage, controlConfig.SystemDefaultRegistry) {
nodeConfig.AgentConfig.PauseImage = controlConfig.SystemDefaultRegistry + "/" + nodeConfig.AgentConfig.PauseImage
}
if !slice.ContainsString(nodeConfig.AgentConfig.AirgapExtraRegistry, controlConfig.SystemDefaultRegistry) {
nodeConfig.AgentConfig.AirgapExtraRegistry = append(nodeConfig.AgentConfig.AirgapExtraRegistry, controlConfig.SystemDefaultRegistry)
}
}
nodeConfig.AgentConfig.ExtraKubeletArgs = envInfo.ExtraKubeletArgs
nodeConfig.AgentConfig.ExtraKubeProxyArgs = envInfo.ExtraKubeProxyArgs
nodeConfig.AgentConfig.NodeTaints = envInfo.Taints
nodeConfig.AgentConfig.NodeLabels = envInfo.Labels
nodeConfig.AgentConfig.ImageCredProvBinDir = envInfo.ImageCredProvBinDir
nodeConfig.AgentConfig.ImageCredProvConfig = envInfo.ImageCredProvConfig
nodeConfig.AgentConfig.PrivateRegistry = envInfo.PrivateRegistry
nodeConfig.AgentConfig.DisableCCM = controlConfig.DisableCCM
nodeConfig.AgentConfig.DisableNPC = controlConfig.DisableNPC
nodeConfig.AgentConfig.DisableKubeProxy = controlConfig.DisableKubeProxy
nodeConfig.AgentConfig.Rootless = envInfo.Rootless
nodeConfig.AgentConfig.PodManifests = filepath.Join(envInfo.DataDir, "agent", DefaultPodManifestPath)
nodeConfig.AgentConfig.ProtectKernelDefaults = envInfo.ProtectKernelDefaults
if err := validateNetworkConfig(nodeConfig); err != nil {
return nil, err
}
return nodeConfig, nil
}
func getConfig(info *clientaccess.Info) (*config.Control, error) {
data, err := info.Get("/v1-" + version.Program + "/config")
if err != nil {
return nil, err
}
controlControl := &config.Control{}
return controlControl, json.Unmarshal(data, controlControl)
}
// validateNetworkConfig ensures that the network configuration values provided by the server make sense.
func validateNetworkConfig(nodeConfig *config.Node) error {
// Old versions of the server do not send enough information to correctly start the NPC. Users
// need to upgrade the server to at least the same version as the agent, or disable the NPC
// cluster-wide.
if nodeConfig.AgentConfig.DisableNPC == false && (nodeConfig.AgentConfig.ServiceCIDR == nil || nodeConfig.AgentConfig.ServiceNodePortRange.Size == 0) {
return fmt.Errorf("incompatible down-level server detected; servers must be upgraded to at least %s, or restarted with --disable-network-policy", version.Version)
}
return nil
}