Merge pull request #239 from xlgao-zju/reload-apparmor-profile

reload default apparmor profile if it is unloaded

server/apparmor/apparmor_common.go

@@ -0,0 +1,14 @@
+package apparmor
+
+const (
+	// DefaultApparmorProfile is the name of default apparmor profile name.
+	DefaultApparmorProfile = "ocid-default"
+
+	// ContainerAnnotationKeyPrefix is the prefix to an annotation key specifying a container profile.
+	ContainerAnnotationKeyPrefix = "container.apparmor.security.beta.kubernetes.io/"
+
+	// ProfileRuntimeDefault is he profile specifying the runtime default.
+	ProfileRuntimeDefault = "runtime/default"
+	// ProfileNamePrefix is the prefix for specifying profiles loaded on the node.
+	ProfileNamePrefix = "localhost/"
+)

server/apparmor/apparmor_supported.go

@@ -4,35 +4,20 @@ package apparmor
 
 import (
 	"bufio"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
 	"path"
 	"strings"
-	"time"
 
-	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/utils/templates"
 	"github.com/opencontainers/runc/libcontainer/apparmor"
 )
 
 const (
-	// defaultApparmorProfile is the name of default apparmor profile name.
-	defaultApparmorProfile = "ocid-default"
-
 	// profileDirectory is the file store for apparmor profiles and macros.
 	profileDirectory = "/etc/apparmor.d"
-
-	// ContainerAnnotationKeyPrefix is the prefix to an annotation key specifying a container profile.
-	ContainerAnnotationKeyPrefix = "container.apparmor.security.beta.kubernetes.io/"
-
-	// ProfileRuntimeDefault is he profile specifying the runtime default.
-	ProfileRuntimeDefault = "runtime/default"
-	// ProfileNamePrefix is the prefix for specifying profiles loaded on the node.
-	ProfileNamePrefix = "localhost/"
-
-	// readConfigTimeout is the timeout of reading apparmor profiles.
-	readConfigTimeout = 10
 )
 
 // profileData holds information about the given profile for generation.
@@ -47,15 +32,26 @@ type profileData struct {
 	Version int
 }
 
-// InstallDefaultAppArmorProfile installs default apparmor profile.
-func InstallDefaultAppArmorProfile() {
-	if err := InstallDefault(defaultApparmorProfile); err != nil {
-		// Allow daemon to run if loading failed, but are active
-		// (possibly through another run, manually, or via system startup)
-		if !IsLoaded(defaultApparmorProfile) {
-			logrus.Errorf("AppArmor enabled on system but the %s profile could not be loaded.", defaultApparmorProfile)
+// EnsureDefaultApparmorProfile loads default apparmor profile, if it is not loaded.
+func EnsureDefaultApparmorProfile() error {
+	if apparmor.IsEnabled() {
+		loaded, err := IsLoaded(DefaultApparmorProfile)
+		if err != nil {
+			return fmt.Errorf("Could not check if %s AppArmor profile was loaded: %s", DefaultApparmorProfile, err)
+		}
+
+		// Nothing to do.
+		if loaded {
+			return nil
+		}
+
+		// Load the profile.
+		if err := InstallDefault(DefaultApparmorProfile); err != nil {
+			return fmt.Errorf("AppArmor enabled on system but the %s profile could not be loaded.", DefaultApparmorProfile)
 		}
 	}
+
+	return nil
 }
 
 // IsEnabled returns true if apparmor is enabled for the host.
@@ -90,35 +86,30 @@ func InstallDefault(name string) error {
 	return LoadProfile(f.Name())
 }
 
-// IsLoaded checks if a passed profile has been loaded into the kernel.
-func IsLoaded(name string) bool {
+// IsLoaded checks if a profile with the given name has been loaded into the
+// kernel.
+func IsLoaded(name string) (bool, error) {
 	file, err := os.Open("/sys/kernel/security/apparmor/profiles")
 	if err != nil {
-		return false
+		return false, err
 	}
 	defer file.Close()
 
-	ch := make(chan bool, 1)
-
-	go func() {
-		r := bufio.NewReader(file)
-		for {
-			p, err := r.ReadString('\n')
-			if err != nil {
-				ch <- false
-			}
-			if strings.HasPrefix(p, name+" ") {
-				ch <- true
-			}
+	r := bufio.NewReader(file)
+	for {
+		p, err := r.ReadString('\n')
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return false, err
+		}
+		if strings.HasPrefix(p, name+" ") {
+			return true, nil
 		}
-	}()
-
-	select {
-	case <-time.After(time.Duration(readConfigTimeout) * time.Second):
-		return false
-	case enabled := <-ch:
-		return enabled
 	}
+
+	return false, nil
 }
 
 // generateDefault creates an apparmor profile from ProfileData.

server/apparmor/apparmor_unsupported.go

@@ -2,23 +2,14 @@
 
 package apparmor
 
-const (
-	// ContainerAnnotationKeyPrefix is the prefix to an annotation key specifying a container profile.
-	ContainerAnnotationKeyPrefix = "container.apparmor.security.beta.kubernetes.io/"
-
-	// ProfileRuntimeDefault is he profile specifying the runtime default.
-	ProfileRuntimeDefault = "runtime/default"
-	// ProfileNamePrefix is the prefix for specifying profiles loaded on the node.
-	ProfileNamePrefix = "localhost/"
-)
-
 // IsEnabled returns false, when build without apparmor build tag.
 func IsEnabled() bool {
 	return false
 }
 
-// InstallDefaultAppArmorProfile dose nothing, when build without apparmor build tag.
-func InstallDefaultAppArmorProfile() {
+// EnsureDefaultApparmorProfile dose nothing, when build without apparmor build tag.
+func EnsureDefaultApparmorProfile() error {
+	return nil
 }
 
 // GetProfileNameFromPodAnnotations dose nothing, when build without apparmor build tag.

server/container_create.go

@@ -188,6 +188,13 @@ func (s *Server) createSandboxContainer(containerID string, containerName string
 	if s.appArmorEnabled {
 		appArmorProfileName := s.getAppArmorProfileName(sb.annotations, metadata.GetName())
 		if appArmorProfileName != "" {
+			// reload default apparmor profile if it is unloaded.
+			if s.appArmorProfile == apparmor.DefaultApparmorProfile {
+				if err := apparmor.EnsureDefaultApparmorProfile(); err != nil {
+					return nil, err
+				}
+			}
+
 			specgen.SetProcessApparmorProfile(appArmorProfileName)
 		}
 	}

server/server.go

@@ -333,6 +333,7 @@ func New(config *Config) (*Server, error) {
 		},
 		seccompEnabled:  seccompEnabled(),
 		appArmorEnabled: apparmor.IsEnabled(),
+		appArmorProfile: config.ApparmorProfile,
 	}
 	seccompProfile, err := ioutil.ReadFile(config.SeccompProfile)
 	if err != nil {
@@ -344,10 +345,11 @@ func New(config *Config) (*Server, error) {
 	}
 	s.seccompProfile = seccompConfig
 
-	if s.appArmorEnabled {
-		apparmor.InstallDefaultAppArmorProfile()
+	if s.appArmorEnabled && s.appArmorProfile == apparmor.DefaultApparmorProfile {
+		if err := apparmor.EnsureDefaultApparmorProfile(); err != nil {
+			return nil, fmt.Errorf("ensuring the default apparmor profile is installed failed: %v", err)
+		}
 	}
-	s.appArmorProfile = config.ApparmorProfile
 
 	s.podIDIndex = truncindex.NewTruncIndex([]string{})
 	s.podNameIndex = registrar.NewRegistrar()