mirror of https://github.com/k3s-io/k3s
Add AppArmor validation logic
The validation checks the prerequisites described in the [AppArmor proposal](https://github.com/kubernetes/kubernetes/blob/master/docs/proposals/apparmor.md#prerequisites)pull/6/head
Tim St. Clair
parent
475f6c5ef6
commit
bdc306bbfe
|
|
@ -0,0 +1,49 @@
|
|||
/*
|
||||
Copyright 2016 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 apparmor
|
||||
|
||||
import (
|
||||
"strings"
|
||||
|
||||
"k8s.io/kubernetes/pkg/api"
|
||||
)
|
||||
|
||||
// TODO: Move these values into the API package.
|
||||
const (
|
||||
// The prefix to an annotation key specifying a container profile.
|
||||
ContainerAnnotationKeyPrefix = "container.apparmor.security.alpha.kubernetes.io/"
|
||||
|
||||
// The profile specifying the runtime default.
|
||||
ProfileRuntimeDefault = "runtime/default"
|
||||
// The prefix for specifying profiles loaded on the node.
|
||||
ProfileNamePrefix = "localhost/"
|
||||
)
|
||||
|
||||
// Checks whether app armor is required for pod to be run.
|
||||
func isRequired(pod *api.Pod) bool {
|
||||
for key := range pod.Annotations {
|
||||
if strings.HasPrefix(key, ContainerAnnotationKeyPrefix) {
|
||||
return true
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
// Returns the name of the profile to use with the container.
|
||||
func GetProfileName(pod *api.Pod, containerName string) string {
|
||||
return pod.Annotations[ContainerAnnotationKeyPrefix+containerName]
|
||||
}
|
||||
|
|
@ -0,0 +1,24 @@
|
|||
/usr/bin/evince-thumbnailer (enforce)
|
||||
/usr/bin/evince-thumbnailer//sanitized_helper (enforce)
|
||||
/usr/bin/evince-previewer (enforce)
|
||||
/usr/bin/evince-previewer//sanitized_helper (enforce)
|
||||
/usr/bin/evince (enforce)
|
||||
/usr/bin/evince//sanitized_helper (enforce)
|
||||
/usr/lib/telepathy/telepathy-ofono (enforce)
|
||||
/usr/lib/telepathy/telepathy-* (enforce)
|
||||
/usr/lib/telepathy/telepathy-*//sanitized_helper (enforce)
|
||||
/usr/lib/telepathy/telepathy-*//pxgsettings (enforce)
|
||||
/usr/lib/telepathy/mission-control-5 (enforce)
|
||||
/usr/lib/lightdm/lightdm-guest-session (enforce)
|
||||
/usr/lib/lightdm/lightdm-guest-session//chromium (enforce)
|
||||
/usr/sbin/tcpdump (enforce)
|
||||
docker-default (enforce)
|
||||
/usr/sbin/cups-browsed (enforce)
|
||||
/usr/sbin/cupsd (enforce)
|
||||
/usr/lib/cups/backend/cups-pdf (enforce)
|
||||
/usr/sbin/ntpd (enforce)
|
||||
/usr/lib/connman/scripts/dhclient-script (enforce)
|
||||
/usr/lib/NetworkManager/nm-dhcp-client.action (enforce)
|
||||
/sbin/dhclient (enforce)
|
||||
foo-container (complain)
|
||||
foo://namespaced-profile (enforce)
|
||||
|
|
@ -0,0 +1,207 @@
|
|||
/*
|
||||
Copyright 2016 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 apparmor
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"errors"
|
||||
"fmt"
|
||||
"io/ioutil"
|
||||
"os"
|
||||
"path"
|
||||
"strings"
|
||||
|
||||
"k8s.io/kubernetes/pkg/api"
|
||||
"k8s.io/kubernetes/pkg/util"
|
||||
)
|
||||
|
||||
// Whether AppArmor should be disabled by default.
|
||||
// Set to true if the wrong build tags are set (see validate_disabled.go).
|
||||
var isDisabledBuild bool
|
||||
|
||||
// Interface for validating that a pod with with an AppArmor profile can be run by a Node.
|
||||
type Validator interface {
|
||||
Validate(pod *api.Pod) error
|
||||
}
|
||||
|
||||
func NewValidator(runtime string) Validator {
|
||||
if err := validateHost(runtime); err != nil {
|
||||
return &validator{validateHostErr: err}
|
||||
}
|
||||
appArmorFS, err := getAppArmorFS()
|
||||
if err != nil {
|
||||
return &validator{
|
||||
validateHostErr: fmt.Errorf("error finding AppArmor FS: %v", err),
|
||||
}
|
||||
}
|
||||
return &validator{
|
||||
appArmorFS: appArmorFS,
|
||||
}
|
||||
}
|
||||
|
||||
type validator struct {
|
||||
validateHostErr error
|
||||
appArmorFS string
|
||||
}
|
||||
|
||||
func (v *validator) Validate(pod *api.Pod) error {
|
||||
if !isRequired(pod) {
|
||||
return nil
|
||||
}
|
||||
|
||||
if v.validateHostErr != nil {
|
||||
return v.validateHostErr
|
||||
}
|
||||
|
||||
loadedProfiles, err := v.getLoadedProfiles()
|
||||
if err != nil {
|
||||
return fmt.Errorf("could not read loaded profiles: %v", err)
|
||||
}
|
||||
|
||||
for _, container := range pod.Spec.InitContainers {
|
||||
if err := validateProfile(GetProfileName(pod, container.Name), loadedProfiles); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
for _, container := range pod.Spec.Containers {
|
||||
if err := validateProfile(GetProfileName(pod, container.Name), loadedProfiles); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// Verify that the host and runtime is capable of enforcing AppArmor profiles.
|
||||
func validateHost(runtime string) error {
|
||||
// Check build support.
|
||||
if isDisabledBuild {
|
||||
return errors.New("Binary not compiled for linux.")
|
||||
}
|
||||
|
||||
// Check kernel support.
|
||||
if !isAppArmorEnabled() {
|
||||
return errors.New("AppArmor is not enabled on the host")
|
||||
}
|
||||
|
||||
// Check runtime support. Currently only Docker is supported.
|
||||
if runtime != "docker" {
|
||||
return fmt.Errorf("AppArmor is only enabled for 'docker' runtime. Found: %q.", runtime)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// Verify that the profile is valid and loaded.
|
||||
func validateProfile(profile string, loadedProfiles map[string]bool) error {
|
||||
if profile == "" || profile == ProfileRuntimeDefault {
|
||||
return nil
|
||||
}
|
||||
if !strings.HasPrefix(profile, ProfileNamePrefix) {
|
||||
return fmt.Errorf("invalid AppArmor profile name: %q", profile)
|
||||
}
|
||||
|
||||
profileName := strings.TrimPrefix(profile, ProfileNamePrefix)
|
||||
if !loadedProfiles[profileName] {
|
||||
return fmt.Errorf("profile %q is not loaded", profileName)
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
func (v *validator) getLoadedProfiles() (map[string]bool, error) {
|
||||
profilesPath := path.Join(v.appArmorFS, "profiles")
|
||||
profilesFile, err := os.Open(profilesPath)
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("failed to open %s: %v", profilesPath, err)
|
||||
}
|
||||
defer profilesFile.Close()
|
||||
|
||||
profiles := map[string]bool{}
|
||||
scanner := bufio.NewScanner(profilesFile)
|
||||
for scanner.Scan() {
|
||||
profileName := parseProfileName(scanner.Text())
|
||||
if profileName == "" {
|
||||
// Unknown line format; skip it.
|
||||
continue
|
||||
}
|
||||
profiles[profileName] = true
|
||||
}
|
||||
return profiles, nil
|
||||
}
|
||||
|
||||
// The profiles file is formatted with one profile per line, matching a form:
|
||||
// namespace://profile-name (mode)
|
||||
// profile-name (mode)
|
||||
// Where mode is {enforce, complain, kill}. The "namespace://" is only included for namespaced
|
||||
// profiles. For the purposes of Kubernetes, we consider the namespace part of the profile name.
|
||||
func parseProfileName(profileLine string) string {
|
||||
modeIndex := strings.IndexRune(profileLine, '(')
|
||||
if modeIndex < 0 {
|
||||
return ""
|
||||
}
|
||||
return strings.TrimSpace(profileLine[:modeIndex])
|
||||
}
|
||||
|
||||
func getAppArmorFS() (string, error) {
|
||||
mountsFile, err := os.Open("/proc/mounts")
|
||||
if err != nil {
|
||||
return "", fmt.Errorf("could not open /proc/mounts: %v", err)
|
||||
}
|
||||
defer mountsFile.Close()
|
||||
|
||||
scanner := bufio.NewScanner(mountsFile)
|
||||
for scanner.Scan() {
|
||||
fields := strings.Fields(scanner.Text())
|
||||
if len(fields) < 3 {
|
||||
// Unknown line format; skip it.
|
||||
continue
|
||||
}
|
||||
if fields[2] == "securityfs" {
|
||||
appArmorFS := path.Join(fields[1], "apparmor")
|
||||
if ok, err := util.FileExists(appArmorFS); !ok {
|
||||
msg := fmt.Sprintf("path %s does not exist", appArmorFS)
|
||||
if err != nil {
|
||||
return "", fmt.Errorf("%s: %v", msg, err)
|
||||
} else {
|
||||
return "", errors.New(msg)
|
||||
}
|
||||
} else {
|
||||
return appArmorFS, nil
|
||||
}
|
||||
}
|
||||
}
|
||||
if err := scanner.Err(); err != nil {
|
||||
return "", fmt.Errorf("error scanning mounts: %v", err)
|
||||
}
|
||||
|
||||
return "", errors.New("securityfs not found")
|
||||
}
|
||||
|
||||
// isAppArmorEnabled returns true if apparmor is enabled for the host.
|
||||
// This function is forked from
|
||||
// https://github.com/opencontainers/runc/blob/1a81e9ab1f138c091fe5c86d0883f87716088527/libcontainer/apparmor/apparmor.go
|
||||
// to avoid the libapparmor dependency.
|
||||
func isAppArmorEnabled() bool {
|
||||
if _, err := os.Stat("/sys/kernel/security/apparmor"); err == nil && os.Getenv("container") == "" {
|
||||
if _, err = os.Stat("/sbin/apparmor_parser"); err == nil {
|
||||
buf, err := ioutil.ReadFile("/sys/module/apparmor/parameters/enabled")
|
||||
return err == nil && len(buf) > 1 && buf[0] == 'Y'
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
|
@ -0,0 +1,24 @@
|
|||
// +build !linux
|
||||
|
||||
/*
|
||||
Copyright 2016 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 apparmor
|
||||
|
||||
func init() {
|
||||
// If Kubernetes was not built for linux, apparmor is always disabled.
|
||||
isDisabledBuild = true
|
||||
}
|
||||
|
|
@ -0,0 +1,195 @@
|
|||
/*
|
||||
Copyright 2016 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 apparmor
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"testing"
|
||||
|
||||
"k8s.io/kubernetes/pkg/api"
|
||||
|
||||
"github.com/stretchr/testify/assert"
|
||||
)
|
||||
|
||||
func TestGetAppArmorFS(t *testing.T) {
|
||||
// This test only passes on systems running AppArmor with the default configuration.
|
||||
// The test should be manually run if modifying the getAppArmorFS function.
|
||||
t.Skip()
|
||||
|
||||
const expectedPath = "/sys/kernel/security/apparmor"
|
||||
actualPath, err := getAppArmorFS()
|
||||
assert.NoError(t, err)
|
||||
assert.Equal(t, expectedPath, actualPath)
|
||||
}
|
||||
|
||||
func TestValidateHost(t *testing.T) {
|
||||
// This test only passes on systems running AppArmor with the default configuration.
|
||||
// The test should be manually run if modifying the getAppArmorFS function.
|
||||
t.Skip()
|
||||
|
||||
assert.NoError(t, validateHost("docker"))
|
||||
assert.Error(t, validateHost("rkt"))
|
||||
}
|
||||
|
||||
func TestValidateProfile(t *testing.T) {
|
||||
loadedProfiles := map[string]bool{
|
||||
"docker-default": true,
|
||||
"foo-bar": true,
|
||||
"baz": true,
|
||||
"/usr/sbin/ntpd": true,
|
||||
"/usr/lib/connman/scripts/dhclient-script": true,
|
||||
"/usr/lib/NetworkManager/nm-dhcp-client.action": true,
|
||||
"/usr/bin/evince-previewer//sanitized_helper": true,
|
||||
}
|
||||
tests := []struct {
|
||||
profile string
|
||||
expectValid bool
|
||||
}{
|
||||
{"", true},
|
||||
{"runtime/default", true},
|
||||
{"baz", false}, // Missing local prefix.
|
||||
{"localhost//usr/sbin/ntpd", true},
|
||||
{"localhost/foo-bar", true},
|
||||
{"localhost/unloaded", false}, // Not loaded.
|
||||
{"localhost/", false},
|
||||
}
|
||||
|
||||
for _, test := range tests {
|
||||
err := validateProfile(test.profile, loadedProfiles)
|
||||
if test.expectValid {
|
||||
assert.NoError(t, err, "Profile %s should be valid", test.profile)
|
||||
} else {
|
||||
assert.Error(t, err, "Profile %s should not be valid", test.profile)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestValidateBadHost(t *testing.T) {
|
||||
hostErr := errors.New("expected host error")
|
||||
v := &validator{
|
||||
validateHostErr: hostErr,
|
||||
}
|
||||
|
||||
tests := []struct {
|
||||
profile string
|
||||
expectValid bool
|
||||
}{
|
||||
{"", true},
|
||||
{"runtime/default", false},
|
||||
{"localhost/docker-default", false},
|
||||
}
|
||||
|
||||
for _, test := range tests {
|
||||
err := v.Validate(getPodWithProfile(test.profile))
|
||||
if test.expectValid {
|
||||
assert.NoError(t, err, "Pod with profile %q should be valid", test.profile)
|
||||
} else {
|
||||
assert.Equal(t, hostErr, err, "Pod with profile %q should trigger a host validation error", test.profile)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestValidateValidHost(t *testing.T) {
|
||||
v := &validator{
|
||||
appArmorFS: "./testdata/",
|
||||
}
|
||||
|
||||
tests := []struct {
|
||||
profile string
|
||||
expectValid bool
|
||||
}{
|
||||
{"", true},
|
||||
{"runtime/default", true},
|
||||
{"localhost/docker-default", true},
|
||||
{"localhost/foo-container", true},
|
||||
{"localhost//usr/sbin/ntpd", true},
|
||||
{"docker-default", false},
|
||||
{"localhost/foo", false},
|
||||
{"localhost/", false},
|
||||
}
|
||||
|
||||
for _, test := range tests {
|
||||
err := v.Validate(getPodWithProfile(test.profile))
|
||||
if test.expectValid {
|
||||
assert.NoError(t, err, "Pod with profile %q should be valid", test.profile)
|
||||
} else {
|
||||
assert.Error(t, err, "Pod with profile %q should trigger a validation error", test.profile)
|
||||
}
|
||||
}
|
||||
|
||||
// Test multi-container pod.
|
||||
pod := &api.Pod{
|
||||
ObjectMeta: api.ObjectMeta{
|
||||
Annotations: map[string]string{
|
||||
"container.apparmor.security.alpha.kubernetes.io/init": "localhost/foo-container",
|
||||
"container.apparmor.security.alpha.kubernetes.io/test1": "runtime/default",
|
||||
"container.apparmor.security.alpha.kubernetes.io/test2": "localhost/docker-default",
|
||||
},
|
||||
},
|
||||
Spec: api.PodSpec{
|
||||
InitContainers: []api.Container{
|
||||
{Name: "init"},
|
||||
},
|
||||
Containers: []api.Container{
|
||||
{Name: "test1"},
|
||||
{Name: "test2"},
|
||||
{Name: "no-profile"},
|
||||
},
|
||||
},
|
||||
}
|
||||
assert.NoError(t, v.Validate(pod), "Multi-container pod should validate")
|
||||
for k, val := range pod.Annotations {
|
||||
pod.Annotations[k] = val + "-bad"
|
||||
assert.Error(t, v.Validate(pod), "Multi-container pod with invalid profile %s:%s", k, pod.Annotations[k])
|
||||
pod.Annotations[k] = val // Restore.
|
||||
}
|
||||
}
|
||||
|
||||
func TestParseProfileName(t *testing.T) {
|
||||
tests := []struct{ line, expected string }{
|
||||
{"foo://bar/baz (kill)", "foo://bar/baz"},
|
||||
{"foo-bar (enforce)", "foo-bar"},
|
||||
{"/usr/foo/bar/baz (complain)", "/usr/foo/bar/baz"},
|
||||
}
|
||||
for _, test := range tests {
|
||||
name := parseProfileName(test.line)
|
||||
assert.Equal(t, test.expected, name, "Parsing %s", test.line)
|
||||
}
|
||||
}
|
||||
|
||||
func getPodWithProfile(profile string) *api.Pod {
|
||||
annotations := map[string]string{
|
||||
"container.apparmor.security.alpha.kubernetes.io/test": profile,
|
||||
}
|
||||
if profile == "" {
|
||||
annotations = map[string]string{
|
||||
"foo": "bar",
|
||||
}
|
||||
}
|
||||
return &api.Pod{
|
||||
ObjectMeta: api.ObjectMeta{
|
||||
Annotations: annotations,
|
||||
},
|
||||
Spec: api.PodSpec{
|
||||
Containers: []api.Container{
|
||||
{
|
||||
Name: "test",
|
||||
},
|
||||
},
|
||||
},
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue