clean up cloud provider code because cloud provider only supports empty or external and cloud is nil

Signed-off-by: carlory <baofa.fan@daocloud.io>

Author: carlory

cmd/kubelet/app/options/options.go

@@ -290,14 +290,14 @@ func (f *KubeletFlags) AddFlags(mainfs *pflag.FlagSet) {
 "On success, a kubeconfig file referencing the generated client certificate and key is written to the path specified by --kubeconfig. "+
 "The client certificate and key file will be stored in the directory pointed by --cert-dir.")
 
-fs.StringVar(&f.HostnameOverride, "hostname-override", f.HostnameOverride, "If non-empty, will use this string as identification instead of the actual hostname. If --cloud-provider is set, the cloud provider determines the name of the node (consult cloud provider documentation to determine if and how the hostname is used).")
+fs.StringVar(&f.HostnameOverride, "hostname-override", f.HostnameOverride, "If non-empty, will use this string as identification instead of the actual hostname.")
 
 fs.StringVar(&f.NodeIP, "node-ip", f.NodeIP, "IP address (or comma-separated dual-stack IP addresses) of the node. If unset, kubelet will use the node's default IPv4 address, if any, or its default IPv6 address if it has no IPv4 addresses. You can pass '::' to make it prefer the default IPv6 address rather than the default IPv4 address. If cloud-provider is set to external, this flag will help to bootstrap the node with the corresponding IP.")
 
 fs.StringVar(&f.CertDirectory, "cert-dir", f.CertDirectory, "The directory where the TLS certs are located. "+
 "If --tls-cert-file and --tls-private-key-file are provided, this flag will be ignored.")
 
-fs.StringVar(&f.CloudProvider, "cloud-provider", f.CloudProvider, "The provider for cloud services. Set to empty string for running with no cloud provider. Set to 'external' for running with an external cloud provider. If set, the cloud provider determines the name of the node (consult cloud provider documentation to determine if and how the hostname is used).")
+fs.StringVar(&f.CloudProvider, "cloud-provider", f.CloudProvider, "The provider for cloud services. Set to empty string for running with no cloud provider. Set to 'external' for running with an external cloud provider.")
 
 fs.StringVar(&f.RootDirectory, "root-dir", f.RootDirectory, "Directory path for managing kubelet files (volume mounts,etc).")
 fs.BoolVar(&f.SeccompDefault, "seccomp-default", f.SeccompDefault, "Enable the use of `RuntimeDefault` as the default seccomp profile for all workloads.")
@@ -320,8 +320,6 @@ func (f *KubeletFlags) AddFlags(mainfs *pflag.FlagSet) {
 fs.MarkDeprecated("register-schedulable", "will be removed in a future version")
 fs.StringVar(&f.ExperimentalMounterPath, "experimental-mounter-path", f.ExperimentalMounterPath, "[Experimental] Path of mounter binary. Leave empty to use the default mount.")
 fs.MarkDeprecated("experimental-mounter-path", "will be removed in 1.25 or later. in favor of using CSI.")
-fs.StringVar(&f.CloudConfigFile, "cloud-config", f.CloudConfigFile, "The path to the cloud provider configuration file. Empty string for no configuration file.")
-fs.MarkDeprecated("cloud-config", "will be removed in 1.25 or later, in favor of removing cloud provider code from Kubelet.")
 fs.BoolVar(&f.ExperimentalNodeAllocatableIgnoreEvictionThreshold, "experimental-allocatable-ignore-eviction", f.ExperimentalNodeAllocatableIgnoreEvictionThreshold, "When set to 'true', Hard Eviction Thresholds will be ignored while calculating Node Allocatable. See https://kubernetes.io/docs/tasks/administer-cluster/reserve-compute-resources/ for more details. [default=false]")
 fs.MarkDeprecated("experimental-allocatable-ignore-eviction", "will be removed in 1.25 or later.")
 }

cmd/kubelet/app/server.go

@@ -75,7 +75,6 @@ import (
 "k8s.io/client-go/util/certificate"
 "k8s.io/client-go/util/connrotation"
 "k8s.io/client-go/util/keyutil"
-cloudprovider "k8s.io/cloud-provider"
 cliflag "k8s.io/component-base/cli/flag"
 "k8s.io/component-base/configz"
 "k8s.io/component-base/featuregate"
@@ -505,7 +504,6 @@ func UnsecuredDependencies(s *options.KubeletServer, featureGate featuregate.Fea
 return &kubelet.Dependencies{
 Auth: nil, // default does not enforce auth[nz]
 CAdvisorInterface: nil, // cadvisor.New launches background processes (bg http.ListenAndServe, and some bg cleaners), not set here
-Cloud: nil, // cloud provider might start background processes
 ContainerManager: nil,
 KubeClient: nil,
 HeartbeatClient: nil,
@@ -661,22 +659,11 @@ func run(ctx context.Context, s *options.KubeletServer, kubeDeps *kubelet.Depend
 }
 }
 
-if kubeDeps.Cloud == nil {
-if !cloudprovider.IsExternal(s.CloudProvider) && len(s.CloudProvider) != 0 {
-// internal cloud provider loops are disabled
-cloudprovider.DisableWarningForProvider(s.CloudProvider)
-return cloudprovider.ErrorForDisabledProvider(s.CloudProvider)
-}
-}
-
 hostName, err := nodeutil.GetHostname(s.HostnameOverride)
 if err != nil {
 return err
 }
-nodeName, err := getNodeName(kubeDeps.Cloud, hostName)
-if err != nil {
-return err
-}
+nodeName := types.NodeName(hostName)
 
 // if in standalone mode, indicate as much by setting all clients to nil
 switch {
@@ -1112,28 +1099,6 @@ func kubeClientConfigOverrides(s *options.KubeletServer, clientConfig *restclien
 clientConfig.Burst = int(s.KubeAPIBurst)
 }
 
-// getNodeName returns the node name according to the cloud provider
-// if cloud provider is specified. Otherwise, returns the hostname of the node.
-func getNodeName(cloud cloudprovider.Interface, hostname string) (types.NodeName, error) {
-if cloud == nil {
-return types.NodeName(hostname), nil
-}
-
-instances, ok := cloud.Instances()
-if !ok {
-return "", fmt.Errorf("failed to get instances from cloud provider")
-}
-
-nodeName, err := instances.CurrentNodeName(context.TODO(), hostname)
-if err != nil {
-return "", fmt.Errorf("error fetching current node name from cloud provider: %w", err)
-}
-
-klog.V(2).InfoS("Cloud provider determined current node", "nodeName", klog.KRef("", string(nodeName)))
-
-return nodeName, nil
-}
-
 // InitializeTLS checks for a configured TLSCertFile and TLSPrivateKeyFile: if unspecified a new self-signed
 // certificate and key file are generated. Returns a configured server.TLSOptions object.
 func InitializeTLS(kf *options.KubeletFlags, kc *kubeletconfiginternal.KubeletConfiguration) (*server.TLSOptions, error) {
@@ -1244,12 +1209,7 @@ func RunKubelet(ctx context.Context, kubeServer *options.KubeletServer, kubeDeps
 if err != nil {
 return err
 }
-// Query the cloud provider for our node name, default to hostname if kubeDeps.Cloud == nil
-nodeName, err := getNodeName(kubeDeps.Cloud, hostname)
-if err != nil {
-return err
-}
-hostnameOverridden := len(kubeServer.HostnameOverride) > 0
+nodeName := types.NodeName(hostname)
 // Setup event recorder if required.
 makeEventRecorder(ctx, kubeDeps, nodeName)
 
@@ -1275,7 +1235,6 @@ func RunKubelet(ctx context.Context, kubeServer *options.KubeletServer, kubeDeps
 k, err := createAndInitKubelet(kubeServer,
 kubeDeps,
 hostname,
-hostnameOverridden,
 nodeName,
 nodeIPs)
 if err != nil {
@@ -1316,7 +1275,6 @@ func startKubelet(k kubelet.Bootstrap, podCfg *config.PodConfig, kubeCfg *kubele
 func createAndInitKubelet(kubeServer *options.KubeletServer,
 kubeDeps *kubelet.Dependencies,
 hostname string,
-hostnameOverridden bool,
 nodeName types.NodeName,
 nodeIPs []net.IP) (k kubelet.Bootstrap, err error) {
 // TODO: block until all sources have delivered at least one update to the channel, or break the sync loop
@@ -1326,7 +1284,6 @@ func createAndInitKubelet(kubeServer *options.KubeletServer,
 kubeDeps,
 &kubeServer.ContainerRuntimeOptions,
 hostname,
-hostnameOverridden,
 nodeName,
 nodeIPs,
 kubeServer.ProviderID,