Merge pull request #7815 from priyawadhwa/systemd

Add option to force docker to use systemd as cgroup manager

cmd/minikube/cmd/start_flags.go

@@ -99,6 +99,7 @@ const (
 	nodes                   = "nodes"
 	preload                 = "preload"
 	deleteOnFailure         = "delete-on-failure"
+	forceSystemd            = "force-systemd"
 	kicBaseImage            = "base-image"
 )
 
@@ -138,6 +139,7 @@ func initMinikubeFlags() {
 	startCmd.Flags().IntP(nodes, "n", 1, "The number of nodes to spin up. Defaults to 1.")
 	startCmd.Flags().Bool(preload, true, "If set, download tarball of preloaded images if available to improve start time. Defaults to true.")
 	startCmd.Flags().Bool(deleteOnFailure, false, "If set, delete the current cluster if start fails and try again. Defaults to false.")
+	startCmd.Flags().Bool(forceSystemd, false, "If set, force the container runtime to use sytemd as cgroup manager. Currently available for docker and crio. Defaults to false.")
 }
 
 // initKubernetesFlags inits the commandline flags for kubernetes related options

hack/preload-images/generate.go

@@ -87,7 +87,7 @@ func generateTarball(kubernetesVersion, containerRuntime, tarballFilename string
 	if err != nil {
 		return errors.Wrap(err, "failed create new runtime")
 	}
-	if err := cr.Enable(true); err != nil {
+	if err := cr.Enable(true, false); err != nil {
 		return errors.Wrap(err, "enable container runtime")
 	}
 

pkg/minikube/cruntime/containerd.go

@@ -197,7 +197,7 @@ func generateContainerdConfig(cr CommandRunner, imageRepository string, kv semve
 }
 
 // Enable idempotently enables containerd on a host
-func (r *Containerd) Enable(disOthers bool) error {
+func (r *Containerd) Enable(disOthers, _ bool) error {
 	if disOthers {
 		if err := disableOthers(r, r.Runner); err != nil {
 			glog.Warningf("disableOthers: %v", err)

pkg/minikube/cruntime/crio.go

@@ -110,7 +110,7 @@ func (r *CRIO) Active() bool {
 }
 
 // Enable idempotently enables CRIO on a host
-func (r *CRIO) Enable(disOthers bool) error {
+func (r *CRIO) Enable(disOthers, _ bool) error {
 	if disOthers {
 		if err := disableOthers(r, r.Runner); err != nil {
 			glog.Warningf("disableOthers: %v", err)

pkg/minikube/cruntime/cruntime.go

@@ -63,7 +63,7 @@ type Manager interface {
 	// Version retrieves the current version of this runtime
 	Version() (string, error)
 	// Enable idempotently enables this runtime on a host
-	Enable(bool) error
+	Enable(bool, bool) error
 	// Disable idempotently disables this runtime on a host
 	Disable() error
 	// Active returns whether or not a runtime is active on a host

pkg/minikube/cruntime/cruntime_test.go

@@ -581,7 +581,7 @@ func TestEnable(t *testing.T) {
 			if err != nil {
 				t.Fatalf("New(%s): %v", tc.runtime, err)
 			}
-			err = cr.Enable(true)
+			err = cr.Enable(true, false)
 			if err != nil {
 				t.Errorf("%s disable unexpected error: %v", tc.runtime, err)
 			}

pkg/minikube/cruntime/docker.go

@@ -103,13 +103,20 @@ func (r *Docker) Active() bool {
 }
 
 // Enable idempotently enables Docker on a host
-func (r *Docker) Enable(disOthers bool) error {
+func (r *Docker) Enable(disOthers, forceSystemd bool) error {
 	if disOthers {
 		if err := disableOthers(r, r.Runner); err != nil {
 			glog.Warningf("disableOthers: %v", err)
 		}
 	}
 
+	if forceSystemd {
+		if err := r.forceSystemd(); err != nil {
+			return err
+		}
+		return r.Init.Restart("docker")
+	}
+
 	return r.Init.Start("docker")
 }
 
@@ -274,6 +281,22 @@ func (r *Docker) SystemLogCmd(len int) string {
 	return fmt.Sprintf("sudo journalctl -u docker -n %d", len)
 }
 
+// ForceSystemd forces the docker daemon to use systemd as cgroup manager
+func (r *Docker) forceSystemd() error {
+	glog.Infof("Forcing docker to use systemd as cgroup manager...")
+	daemonConfig := `{
+"exec-opts": ["native.cgroupdriver=systemd"],
+"log-driver": "json-file",
+"log-opts": {
+	"max-size": "100m"
+},
+"storage-driver": "overlay2"
+}
+`
+	ma := assets.NewMemoryAsset([]byte(daemonConfig), "/etc/docker", "daemon.json", "0644")
+	return r.Runner.Copy(ma)
+}
+
 // Preload preloads docker with k8s images:
 // 1. Copy over the preloaded tarball into the VM
 // 2. Extract the preloaded tarball to the correct directory

pkg/minikube/node/start.go

@@ -255,7 +255,7 @@ func configureRuntimes(runner cruntime.CommandRunner, cc config.ClusterConfig, k
 		}
 	}
 
-	err = cr.Enable(disableOthers)
+	err = cr.Enable(disableOthers, viper.GetBool("force-systemd"))
 	if err != nil {
 		debug.PrintStack()
 		exit.WithError("Failed to enable container runtime", err)

site/content/en/docs/commands/start.md

@@ -50,6 +50,7 @@ minikube start [flags]
                                           		Valid kubeadm parameters: ignore-preflight-errors, dry-run, kubeconfig, kubeconfig-dir, node-name, cri-socket, experimental-upload-certs, certificate-key, rootfs, skip-phases, pod-network-cidr
       --feature-gates string              A set of key=value pairs that describe feature gates for alpha/experimental features.
       --force                             Force minikube to perform possibly dangerous operations
+      --force-systemd                     If set, force the container runtime to use sytemd as cgroup manager. Currently available for docker and crio. Defaults to false.
   -h, --help                              help for start
       --host-dns-resolver                 Enable host resolver for NAT DNS requests (virtualbox driver only) (default true)
       --host-only-cidr string             The CIDR to be used for the minikube VM (virtualbox driver only) (default "192.168.99.1/24")

test/integration/docker_test.go

@@ -63,3 +63,30 @@ func TestDockerFlags(t *testing.T) {
 		}
 	}
 }
+
+func TestForceSystemd(t *testing.T) {
+	if NoneDriver() {
+		t.Skip("skipping: none driver does not support ssh or bundle docker")
+	}
+	MaybeParallel(t)
+
+	profile := UniqueProfileName("force-systemd")
+	ctx, cancel := context.WithTimeout(context.Background(), Minutes(30))
+	defer CleanupWithLogs(t, profile, cancel)
+
+	// Use the most verbose logging for the simplest test. If it fails, something is very wrong.
+	args := append([]string{"start", "-p", profile, "--force-systemd", "--alsologtostderr", "-v=5"}, StartArgs()...)
+	rr, err := Run(t, exec.CommandContext(ctx, Target(), args...))
+	if err != nil {
+		t.Errorf("failed to start minikube with args: %q : %v", rr.Command(), err)
+	}
+
+	rr, err = Run(t, exec.CommandContext(ctx, Target(), "-p", profile, "ssh", "docker info --format {{.CgroupDriver}}"))
+	if err != nil {
+		t.Errorf("failed to get docker cgroup driver. args %q: %v", rr.Command(), err)
+	}
+
+	if !strings.Contains(rr.Output(), "systemd") {
+		t.Fatalf("expected systemd cgroup driver, got: %v", rr.Output())
+	}
+}