Merge pull request #99647 from neolit123/1.21-remove-cgroup-driver-detection

kubeadm: remove the cgroup driver detection for docker

cmd/kubeadm/app/componentconfigs/kubelet.go

@@ -24,14 +24,12 @@ import (
 	"k8s.io/klog/v2"
 	kubeletconfig "k8s.io/kubelet/config/v1beta1"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/initsystem"
-	utilsexec "k8s.io/utils/exec"
 	utilpointer "k8s.io/utils/pointer"
 
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
 	kubeadmapiv1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta3"
 	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	"k8s.io/kubernetes/cmd/kubeadm/app/features"
-	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
 )
 
 const (
@@ -201,20 +199,6 @@ func (kc *kubeletConfig) Default(cfg *kubeadmapi.ClusterConfiguration, _ *kubead
 	// There is no way to determine if the user has set this or not, given the field is a non-pointer.
 	kc.config.RotateCertificates = kubeletRotateCertificates
 
-	// TODO: Conditionally set CgroupDriver to either `systemd` or `cgroupfs` for CRI other than Docker
-	if nodeRegOpts.CRISocket == constants.DefaultDockerCRISocket {
-		driver, err := kubeadmutil.GetCgroupDriverDocker(utilsexec.New())
-		if err != nil {
-			klog.Warningf("cannot automatically set CgroupDriver when starting the Kubelet: %v", err)
-		} else {
-			// if we can parse the right cgroup driver from docker info,
-			// we should always override CgroupDriver here no matter user specifies this value explicitly or not
-			if kc.config.CgroupDriver != "" && kc.config.CgroupDriver != driver {
-				klog.Warningf("detected %q as the Docker cgroup driver, the provided value %q in %q will be overrided", driver, kc.config.CgroupDriver, kind)
-			}
-			kc.config.CgroupDriver = driver
-		}
-	}
 	if len(kc.config.CgroupDriver) == 0 {
 		klog.V(1).Infof("the value of KubeletConfiguration.cgroupDriver is empty; setting it to %q", constants.CgroupDriverSystemd)
 		kc.config.CgroupDriver = constants.CgroupDriverSystemd

cmd/kubeadm/app/constants/constants.go

@@ -398,8 +398,6 @@ const (
 
 	// CgroupDriverSystemd holds the systemd driver type
 	CgroupDriverSystemd = "systemd"
-	// CgroupDriverCgroupfs holds the cgroupfs driver type
-	CgroupDriverCgroupfs = "cgroupfs"
 )
 
 var (

cmd/kubeadm/app/preflight/checks.go

@@ -223,14 +223,6 @@ func (IsPrivilegedUserCheck) Name() string {
 	return "IsPrivilegedUser"
 }
 
-// IsDockerSystemdCheck verifies if Docker is setup to use systemd as the cgroup driver.
-type IsDockerSystemdCheck struct{}
-
-// Name returns name for IsDockerSystemdCheck
-func (IsDockerSystemdCheck) Name() string {
-	return "IsDockerSystemdCheck"
-}
-
 // DirAvailableCheck checks if the given directory either does not exist, or is empty.
 type DirAvailableCheck struct {
 	Path  string
@@ -1020,10 +1012,6 @@ func addCommonChecks(execer utilsexec.Interface, k8sVersion string, nodeReg *kub
 		if containerRuntime.IsDocker() {
 			isDocker = true
 			checks = append(checks, ServiceCheck{Service: "docker", CheckIfActive: true})
-			// Linux only
-			// TODO: support other CRIs for this check eventually
-			// https://github.com/kubernetes/kubeadm/issues/874
-			checks = append(checks, IsDockerSystemdCheck{})
 		}
 	}
 

cmd/kubeadm/app/preflight/checks_darwin.go

@@ -20,12 +20,6 @@ package preflight
 
 // This is a MacOS stub
 
-// Check validates if Docker is setup to use systemd as the cgroup driver.
-// No-op for Darwin (MacOS).
-func (idsc IsDockerSystemdCheck) Check() (warnings, errorList []error) {
-	return nil, nil
-}
-
 // Check number of memory required by kubeadm
 // No-op for Darwin (MacOS).
 func (mc MemCheck) Check() (warnings, errorList []error) {

cmd/kubeadm/app/preflight/checks_linux.go

@@ -22,28 +22,8 @@ import (
 	"syscall"
 
 	"github.com/pkg/errors"
-	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
-	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
-	"k8s.io/utils/exec"
 )
 
-// Check validates if Docker is setup to use systemd as the cgroup driver.
-func (idsc IsDockerSystemdCheck) Check() (warnings, errorList []error) {
-	driver, err := kubeadmutil.GetCgroupDriverDocker(exec.New())
-	if err != nil {
-		return nil, []error{err}
-	}
-	if driver != constants.CgroupDriverSystemd {
-		err = errors.Errorf("detected %q as the Docker cgroup driver. "+
-			"The recommended driver is %q. "+
-			"Please follow the guide at https://kubernetes.io/docs/setup/cri/",
-			driver,
-			constants.CgroupDriverSystemd)
-		return []error{err}, nil
-	}
-	return nil, nil
-}
-
 // Check number of memory required by kubeadm
 func (mc MemCheck) Check() (warnings, errorList []error) {
 	info := syscall.Sysinfo_t{}

cmd/kubeadm/app/preflight/checks_windows.go

@@ -49,12 +49,6 @@ func (ipuc IsPrivilegedUserCheck) Check() (warnings, errorList []error) {
 	return nil, []error{errors.New("user is not running as administrator")}
 }
 
-// Check validates if Docker is setup to use systemd as the cgroup driver.
-// No-op for Windows.
-func (idsc IsDockerSystemdCheck) Check() (warnings, errorList []error) {
-	return nil, nil
-}
-
 // Check number of memory required by kubeadm
 // No-op for Windows.
 func (mc MemCheck) Check() (warnings, errorList []error) {

cmd/kubeadm/app/util/cgroupdriver.go

@@ -1,47 +0,0 @@
-/*
-Copyright 2018 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package util
-
-import (
-	"strings"
-
-	"github.com/pkg/errors"
-
-	utilsexec "k8s.io/utils/exec"
-)
-
-// TODO: add support for detecting the cgroup driver for CRI other than
-// Docker. Currently only Docker driver detection is supported:
-// Discussion:
-//     https://github.com/kubernetes/kubeadm/issues/844
-
-// GetCgroupDriverDocker runs 'docker info -f "{{.CgroupDriver}}"' to obtain the docker cgroup driver
-func GetCgroupDriverDocker(execer utilsexec.Interface) (string, error) {
-	driver, err := callDockerInfo(execer)
-	if err != nil {
-		return "", err
-	}
-	return strings.TrimSuffix(driver, "\n"), nil
-}
-
-func callDockerInfo(execer utilsexec.Interface) (string, error) {
-	out, err := execer.Command("docker", "info", "-f", "{{.CgroupDriver}}").Output()
-	if err != nil {
-		return "", errors.Wrap(err, "cannot execute 'docker info -f {{.CgroupDriver}}'")
-	}
-	return string(out), nil
-}

cmd/kubeadm/app/util/cgroupdriver_test.go

@@ -1,60 +0,0 @@
-/*
-Copyright 2018 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package util
-
-import (
-	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
-	"testing"
-)
-
-func TestGetCgroupDriverDocker(t *testing.T) {
-	testCases := []struct {
-		name          string
-		driver        string
-		expectedError bool
-	}{
-		{
-			name:          "valid: value is 'cgroupfs'",
-			driver:        `cgroupfs`,
-			expectedError: false,
-		},
-		{
-			name:          "valid: value is 'systemd'",
-			driver:        `systemd`,
-			expectedError: false,
-		},
-		{
-			name:          "invalid: empty 'Cgroup Driver' value",
-			driver:        ``,
-			expectedError: true,
-		},
-		{
-			name:          "invalid: unknown 'Cgroup Driver' value",
-			driver:        `invalid-value`,
-			expectedError: true,
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			result := tc.driver != constants.CgroupDriverCgroupfs && tc.driver != constants.CgroupDriverSystemd
-			if result != tc.expectedError {
-				t.Fatalf("expected error: %v, saw: %v", tc.expectedError, result)
-			}
-		})
-	}
-}