Add env variable to configure force-systemd

pkg/minikube/constants/constants.go

@@ -65,6 +65,8 @@ const (
 	MinikubeActiveDockerdEnv = "MINIKUBE_ACTIVE_DOCKERD"
 	// PodmanVarlinkBridgeEnv is used for podman settings
 	PodmanVarlinkBridgeEnv = "PODMAN_VARLINK_BRIDGE"
+	// MinikubeForceSystemdEnv is used to force systemd as cgroup manager for the container runtime
+	MinikubeForceSystemdEnv = "MINIKUBE_FORCE_SYSTEMD"
 )
 
 var (

pkg/minikube/node/start.go

@@ -252,7 +252,7 @@ func configureRuntimes(runner cruntime.CommandRunner, cc config.ClusterConfig, k
 		}
 	}
 
-	err = cr.Enable(disableOthers, viper.GetBool("force-systemd"))
+	err = cr.Enable(disableOthers, forceSystemd())
 	if err != nil {
 		debug.PrintStack()
 		exit.WithError("Failed to enable container runtime", err)
@@ -261,6 +261,10 @@ func configureRuntimes(runner cruntime.CommandRunner, cc config.ClusterConfig, k
 	return cr
 }
 
+func forceSystemd() bool {
+	return viper.GetBool("force-systemd") || os.Getenv(constants.MinikubeForceSystemdEnv) == "true"
+}
+
 // setupKubeAdm adds any requested files into the VM before Kubernetes is started
 func setupKubeAdm(mAPI libmachine.API, cfg config.ClusterConfig, n config.Node, r command.Runner) bootstrapper.Bootstrapper {
 	bs, err := cluster.Bootstrapper(mAPI, viper.GetString(cmdcfg.Bootstrapper), cfg, r)

test/integration/docker_test.go

@@ -20,6 +20,7 @@ package integration
 
 import (
 	"context"
+	"os"
 	"os/exec"
 	"strings"
 	"testing"
@@ -64,13 +65,13 @@ func TestDockerFlags(t *testing.T) {
 	}
 }
 
-func TestForceSystemd(t *testing.T) {
+func TestForceSystemdFlag(t *testing.T) {
 	if NoneDriver() {
 		t.Skip("skipping: none driver does not support ssh or bundle docker")
 	}
 	MaybeParallel(t)
 
-	profile := UniqueProfileName("force-systemd")
+	profile := UniqueProfileName("force-systemd-flag")
 	ctx, cancel := context.WithTimeout(context.Background(), Minutes(30))
 	defer CleanupWithLogs(t, profile, cancel)
 
@@ -90,3 +91,31 @@ func TestForceSystemd(t *testing.T) {
 		t.Fatalf("expected systemd cgroup driver, got: %v", rr.Output())
 	}
 }
+
+func TestForceSystemdEnv(t *testing.T) {
+	if NoneDriver() {
+		t.Skip("skipping: none driver does not support ssh or bundle docker")
+	}
+	MaybeParallel(t)
+
+	profile := UniqueProfileName("force-systemd-env")
+	ctx, cancel := context.WithTimeout(context.Background(), Minutes(30))
+	defer CleanupWithLogs(t, profile, cancel)
+
+	args := append([]string{"start", "-p", profile, "--memory=1800", "--alsologtostderr", "-v=5"}, StartArgs()...)
+	cmd := exec.CommandContext(ctx, Target(), args...)
+	cmd.Env = append(os.Environ(), "MINIKUBE_FORCE_SYSTEMD=true")
+	rr, err := Run(t, cmd)
+	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())
+	}
+}