Simplify containerd runtime configuration for gVisor

The previous code had a copy of `config.toml` which is easy to get out of
sync. Instead, append the necessary configuration to the existing file
to retain the rest of the configuration.

Also changed the location where `runsc` is downloaded to use the latest
release instead of hardcondig to a release which gets old quickly.

deploy/addons/assets.go

@@ -109,7 +109,7 @@ var (
 	LogviewerAssets embed.FS
 
 	// GvisorAssets assets for gvisor addon
-	//go:embed gvisor/*.tmpl gvisor/*.toml
+	//go:embed gvisor/*.tmpl
 	GvisorAssets embed.FS
 
 	// HelmTillerAssets assets for helm-tiller addon

deploy/addons/gvisor/README.md

@@ -71,4 +71,4 @@ NAME      READY     STATUS        RESTARTS   AGE
 gvisor    1/1       Terminating   0          5m
 ```
 
-_Note: Once gVisor is disabled, any pod with the `gvisor` Runtime Class or `io.kubernetes.cri.untrusted-workload` annotation will fail with a FailedCreatePodSandBox error._
+_Note: Once gVisor is disabled, any pod with the `gvisor` Runtime Class will fail with a FailedCreatePodSandBox error._

pkg/gvisor/disable.go

@@ -28,11 +28,11 @@ import (
 // Disable reverts containerd config files and restarts containerd
 func Disable() error {
 	log.Print("Disabling gvisor...")
-	if err := os.Remove(filepath.Join(nodeDir, containerdConfigTomlPath)); err != nil {
-		return errors.Wrapf(err, "removing %s", containerdConfigTomlPath)
+	if err := os.Remove(filepath.Join(nodeDir, containerdConfigPath)); err != nil {
+		return errors.Wrapf(err, "removing %s", containerdConfigPath)
 	}
-	log.Printf("Restoring default config.toml at %s", containerdConfigTomlPath)
-	if err := mcnutils.CopyFile(filepath.Join(nodeDir, storedContainerdConfigTomlPath), filepath.Join(nodeDir, containerdConfigTomlPath)); err != nil {
+	log.Printf("Restoring default config.toml at %s", containerdConfigPath)
+	if err := mcnutils.CopyFile(filepath.Join(nodeDir, containerdConfigBackupPath), filepath.Join(nodeDir, containerdConfigPath)); err != nil {
 		return errors.Wrap(err, "reverting back to default config.toml")
 	}
 	// restart containerd

pkg/gvisor/enable.go

@@ -29,23 +29,28 @@ import (
 
 	"github.com/docker/machine/libmachine/mcnutils"
 	"github.com/pkg/errors"
-	"k8s.io/minikube/pkg/minikube/assets"
-	"k8s.io/minikube/pkg/minikube/constants"
-	"k8s.io/minikube/pkg/minikube/vmpath"
 )
 
 const (
-	nodeDir                        = "/node"
-	containerdConfigTomlPath       = "/etc/containerd/config.toml"
-	storedContainerdConfigTomlPath = "/tmp/config.toml"
-	gvisorContainerdShimURL        = "https://github.com/google/gvisor-containerd-shim/releases/download/v0.0.3/containerd-shim-runsc-v1.linux-amd64"
-	gvisorURL                      = "https://storage.googleapis.com/gvisor/releases/nightly/2020-02-14/runsc"
+	nodeDir                    = "/node"
+	containerdConfigPath       = "/etc/containerd/config.toml"
+	containerdConfigBackupPath = "/tmp/containerd-config.toml.bak"
+
+	releaseURL = "https://storage.googleapis.com/gvisor/releases/release/latest/x86_64/"
+	shimURL    = releaseURL + "containerd-shim-runsc-v1"
+	gvisorURL  = releaseURL + "runsc"
+
+	configFragment = `
+[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runsc]
+  runtime_type = "io.containerd.runsc.v1"
+  pod_annotations = [ "dev.gvisor.*" ]
+`
 )
 
 // Enable follows these steps for enabling gvisor in minikube:
 //  1. creates necessary directories for storing binaries and runsc logs
 //  2. downloads runsc and gvisor-containerd-shim
-//  3. copies necessary containerd config files
+//  3. configures containerd
 //  4. restarts containerd
 func Enable() error {
 	if err := makeGvisorDirs(); err != nil {
@@ -54,7 +59,7 @@ func Enable() error {
 	if err := downloadBinaries(); err != nil {
 		return errors.Wrap(err, "downloading binaries")
 	}
-	if err := copyConfigFiles(); err != nil {
+	if err := configure(); err != nil {
 		return errors.Wrap(err, "copying config files")
 	}
 	if err := restartContainerd(); err != nil {
@@ -106,7 +111,7 @@ func downloadBinaries() error {
 // downloads the gvisor-containerd-shim
 func gvisorContainerdShim() error {
 	dest := filepath.Join(nodeDir, "usr/bin/containerd-shim-runsc-v1")
-	return downloadFileToDest(gvisorContainerdShimURL, dest)
+	return downloadFileToDest(shimURL, dest)
 }
 
 // downloads the runsc binary and returns a path to the binary
@@ -148,54 +153,23 @@ func downloadFileToDest(url, dest string) error {
 	return nil
 }
 
-// Must write the following files:
-//  1. gvisor-containerd-shim.toml
-//  2. gvisor containerd config.toml
-//
-// and save the default version of config.toml
-func copyConfigFiles() error {
-	log.Printf("Storing default config.toml at %s", storedContainerdConfigTomlPath)
-	if err := mcnutils.CopyFile(filepath.Join(nodeDir, containerdConfigTomlPath), filepath.Join(nodeDir, storedContainerdConfigTomlPath)); err != nil {
+// configure changes containerd `config.toml` file to include runsc runtime. A
+// copy of the original file is stored under `/tmp` to be restored when this
+// plug in is disabled.
+func configure() error {
+	log.Printf("Storing default config.toml at %s", containerdConfigBackupPath)
+	configPath := filepath.Join(nodeDir, containerdConfigPath)
+	if err := mcnutils.CopyFile(configPath, filepath.Join(nodeDir, containerdConfigBackupPath)); err != nil {
 		return errors.Wrap(err, "copying default config.toml")
 	}
-	log.Printf("Copying %s asset to %s", constants.GvisorConfigTomlTargetName, filepath.Join(nodeDir, containerdConfigTomlPath))
-	if err := copyAssetToDest(constants.GvisorConfigTomlTargetName, filepath.Join(nodeDir, containerdConfigTomlPath)); err != nil {
-		return errors.Wrap(err, "copying gvisor version of config.toml")
-	}
-	return nil
-}
-
-func copyAssetToDest(targetName, dest string) error {
-	var asset *assets.BinAsset
-	for _, a := range assets.Addons["gvisor"].Assets {
-		if a.GetTargetName() == targetName {
-			asset = a
-		}
-	}
-	if asset == nil {
-		return fmt.Errorf("no asset matching target %s among %+v", targetName, assets.Addons["gvisor"])
-	}
-
-	// Now, copy the data from this asset to dest
-	src := filepath.Join(vmpath.GuestGvisorDir, asset.GetTargetName())
-	log.Printf("%s asset path: %s", targetName, src)
-	contents, err := os.ReadFile(src)
-	if err != nil {
-		return errors.Wrapf(err, "getting contents of %s", asset.GetSourcePath())
-	}
-	if _, err := os.Stat(dest); err == nil {
-		if err := os.Remove(dest); err != nil {
-			return errors.Wrapf(err, "removing %s", dest)
-		}
-	}
 
-	log.Printf("creating %s", dest)
-	f, err := os.Create(dest)
+	// Append runsc configuration to contained config.
+	config, err := os.OpenFile(configPath, os.O_WRONLY|os.O_APPEND, 0)
 	if err != nil {
-		return errors.Wrapf(err, "creating %s", dest)
+		return err
 	}
-	if _, err := f.Write(contents); err != nil {
-		return errors.Wrapf(err, "writing contents to %s", f.Name())
+	if _, err := config.WriteString(configFragment); err != nil {
+		return errors.Wrap(err, "changing config.toml")
 	}
 	return nil
 }

pkg/minikube/assets/addons.go

@@ -22,12 +22,11 @@ import (
 	"runtime"
 	"strings"
 
-	"github.com/blang/semver/v4"
+	semver "github.com/blang/semver/v4"
 	"github.com/pkg/errors"
 	"github.com/spf13/viper"
 	"k8s.io/minikube/deploy/addons"
 	"k8s.io/minikube/pkg/minikube/config"
-	"k8s.io/minikube/pkg/minikube/constants"
 	"k8s.io/minikube/pkg/minikube/out"
 	"k8s.io/minikube/pkg/minikube/vmpath"
 	"k8s.io/minikube/pkg/util"
@@ -502,11 +501,6 @@ var Addons = map[string]*Addon{
 			vmpath.GuestAddonsDir,
 			"gvisor-runtimeclass.yaml",
 			"0640"),
-		MustBinAsset(addons.GvisorAssets,
-			"gvisor/gvisor-config.toml",
-			vmpath.GuestGvisorDir,
-			constants.GvisorConfigTomlTargetName,
-			"0640"),
 	}, false, "gvisor", "minikube", "", "https://github.com/kubernetes/minikube/blob/master/deploy/addons/gvisor/README.md", map[string]string{
 		"GvisorAddon": "k8s-minikube/gvisor-addon:3@sha256:23eb17d48a66fc2b09c31454fb54ecae520c3e9c9197ef17fcb398b4f31d505a",
 	}, map[string]string{

pkg/minikube/constants/constants.go

@@ -162,8 +162,6 @@ const (
 var (
 	// IsMinikubeChildProcess is the name of "is minikube child process" variable
 	IsMinikubeChildProcess = "IS_MINIKUBE_CHILD_PROCESS"
-	// GvisorConfigTomlTargetName is the go-bindata target name for the gvisor config.toml
-	GvisorConfigTomlTargetName = "gvisor-config.toml"
 	// MountProcessFileName is the filename of the mount process
 	MountProcessFileName = ".mount-process"
 

test/integration/gvisor_addon_test.go

@@ -69,20 +69,12 @@ func TestGvisorAddon(t *testing.T) {
 		t.Fatalf("failed waiting for 'gvisor controller' pod: %v", err)
 	}
 
-	// Create an untrusted workload
-	rr, err = Run(t, exec.CommandContext(ctx, "kubectl", "--context", profile, "replace", "--force", "-f", filepath.Join(*testdataDir, "nginx-untrusted.yaml")))
-	if err != nil {
-		t.Fatalf("%s failed: %v", rr.Command(), err)
-	}
 	// Create gvisor workload
 	rr, err = Run(t, exec.CommandContext(ctx, "kubectl", "--context", profile, "replace", "--force", "-f", filepath.Join(*testdataDir, "nginx-gvisor.yaml")))
 	if err != nil {
 		t.Fatalf("%s failed: %v", rr.Command(), err)
 	}
 
-	if _, err := PodWait(ctx, t, profile, "default", "run=nginx,untrusted=true", Minutes(4)); err != nil {
-		t.Errorf("failed waiting for nginx pod: %v", err)
-	}
 	if _, err := PodWait(ctx, t, profile, "default", "run=nginx,runtime=gvisor", Minutes(4)); err != nil {
 		t.Errorf("failed waitinf for gvisor pod: %v", err)
 	}
@@ -100,9 +92,6 @@ func TestGvisorAddon(t *testing.T) {
 	if _, err := PodWait(ctx, t, profile, "kube-system", "kubernetes.io/minikube-addons=gvisor", Minutes(4)); err != nil {
 		t.Errorf("failed waiting for 'gvisor controller' pod : %v", err)
 	}
-	if _, err := PodWait(ctx, t, profile, "default", "run=nginx,untrusted=true", Minutes(4)); err != nil {
-		t.Errorf("failed waiting for 'nginx' pod : %v", err)
-	}
 	if _, err := PodWait(ctx, t, profile, "default", "run=nginx,runtime=gvisor", Minutes(4)); err != nil {
 		t.Errorf("failed waiting for 'gvisor' pod : %v", err)
 	}