ECS Agent AppArmor Support (aka Ubuntu 22 support)

README.md

@@ -266,6 +266,7 @@ Additionally, the following environment variable(s) can be used to configure the
 | `ECS_ALLOW_OFFHOST_INTROSPECTION_ACCESS` | <true | false> | By default, the ecs-init service adds an iptable rule to block access to ECS Agent's introspection port from off-host (or containers in awsvpc network mode), and removes the rule upon stop. If `ECS_ALLOW_OFFHOST_INTROSPECTION_ACCESS` is set to true, this rule will not be added/removed. | false |
 | `ECS_OFFHOST_INTROSPECTION_INTERFACE_NAME` | `eth0` | Primary network interface name to be used for blocking offhost agent introspection port access. By default, this value is `eth0` | `eth0` |
 | `ECS_AGENT_LABELS` | `{"test.label.1":"value1","test.label.2":"value2"}` | The labels to add to the ECS Agent container. | |
+| `ECS_AGENT_APPARMOR_PROFILE` | `unconfined` | Specifies the name of the AppArmor profile to run the ecs-agent container under. This only applies to AppArmor-enabled systems, such as Ubuntu, Debian, and SUSE. If unset, defaults to the profile written out by ecs-init (ecs-agent-default). | `ecs-agent-default` |
 
 
 

ecs-init/apparmor/apparmor.go

@@ -0,0 +1,92 @@
+package apparmor
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/aws/amazon-ecs-agent/ecs-init/config"
+	"github.com/docker/docker/pkg/aaparser"
+	aaprofile "github.com/docker/docker/profiles/apparmor"
+)
+
+const (
+	ECSAgentDefaultProfileName = config.ECSAgentAppArmorDefaultProfileName
+	appArmorProfileDir         = "/etc/apparmor.d"
+)
+
+const ecsAgentDefaultProfile = `
+#include <tunables/global>
+
+profile ecs-agent-default flags=(attach_disconnected,mediate_deleted) {
+  #include <abstractions/base>
+
+  network inet,
+  network inet6,
+  network netlink,
+  network unix,
+  capability,
+  file,
+  umount,
+  # Host (privileged) processes may send signals to container processes.
+  signal (receive) peer=unconfined,
+  # Container processes may send signals amongst themselves.
+  signal (send,receive) peer=ecs-agent-default,
+
+  # ECS agent requires DBUS send
+  dbus (send,receive) bus=system,
+
+  deny @{PROC}/* w,   # deny write for all files directly in /proc (not in a subdir)
+  # deny write to files not in /proc/<number>/** or /proc/sys/**
+  deny @{PROC}/{[^1-9],[^1-9][^0-9],[^1-9s][^0-9y][^0-9s],[^1-9][^0-9][^0-9][^0-9/]*}/** w,
+  deny @{PROC}/sys/[^k]** w,  # deny /proc/sys except /proc/sys/k* (effectively /proc/sys/kernel)
+  deny @{PROC}/sys/kernel/{?,??,[^s][^h][^m]**} w,  # deny everything except shm* in /proc/sys/kernel/
+  deny @{PROC}/sysrq-trigger rwklx,
+  deny @{PROC}/kcore rwklx,
+
+  deny mount,
+
+  deny /sys/[^f]*/** wklx,
+  deny /sys/f[^s]*/** wklx,
+  deny /sys/fs/[^c]*/** wklx,
+  deny /sys/fs/c[^g]*/** wklx,
+  deny /sys/fs/cg[^r]*/** wklx,
+  deny /sys/firmware/** rwklx,
+  deny /sys/kernel/security/** rwklx,
+
+  # suppress ptrace denials when using 'docker ps' or using 'ps' inside a container
+  ptrace (trace,read,tracedby,readby) peer=ecs-agent-default,
+  ptrace (trace,read,tracedby,readby) peer=docker-default,
+}
+`
+
+var (
+	isProfileLoaded = aaprofile.IsLoaded
+	loadPath        = aaparser.LoadProfile
+	createFile      = os.Create
+)
+
+// LoadDefaultProfile ensures the default profile to be loaded with the given name.
+// Returns nil error if the profile is already loaded.
+func LoadDefaultProfile(profileName string) error {
+	_, err := isProfileLoaded(profileName)
+	if err != nil {
+		return err
+	}
+
+	f, err := createFile(filepath.Join(appArmorProfileDir, profileName))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = f.WriteString(ecsAgentDefaultProfile)
+	if err != nil {
+		return err
+	}
+	path := f.Name()
+
+	if err := loadPath(path); err != nil {
+		return fmt.Errorf("error loading apparmor profile %s: %w", path, err)
+	}
+	return nil
+}

ecs-init/apparmor/apparmor_test.go

@@ -0,0 +1,103 @@
+// Copyright 2015-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//     http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/containerd/containerd/pkg/apparmor"
+	"github.com/docker/docker/pkg/aaparser"
+	aaprofile "github.com/docker/docker/profiles/apparmor"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadDefaultProfile(t *testing.T) {
+	testCases := []struct {
+		name             string
+		profileName      string
+		isLoadedResponse bool
+		isLoadedError    error
+		loadError        error
+		expectedError    error
+	}{
+		{
+			name:             "ProfileIsAlreadyLoaded",
+			profileName:      "testProfile.txt",
+			isLoadedResponse: true,
+			isLoadedError:    nil,
+			loadError:        nil,
+			expectedError:    nil,
+		},
+		{
+			name:             "ProfileNotLoaded",
+			profileName:      "testProfile.txt",
+			isLoadedResponse: false,
+			isLoadedError:    nil,
+			loadError:        nil,
+			expectedError:    nil,
+		},
+		{
+			name:             "IsLoadedError",
+			profileName:      "testProfile.txt",
+			isLoadedResponse: false,
+			isLoadedError:    errors.New("mock isLoaded error"),
+			loadError:        nil,
+			expectedError:    errors.New("mock isLoaded error"),
+		},
+		{
+			name:             "LoadProfileError",
+			profileName:      "testProfile.txt",
+			isLoadedResponse: false,
+			isLoadedError:    nil,
+			loadError:        errors.New("mock load error"),
+			expectedError:    errors.New("mock load error"),
+		},
+	}
+	defer func() {
+		isProfileLoaded = aaprofile.IsLoaded
+		loadPath = aaparser.LoadProfile
+		createFile = os.Create
+	}()
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			if !apparmor.HostSupports() {
+				t.Skip()
+			}
+			tmpdir := os.TempDir()
+			filePath, err := os.MkdirTemp(tmpdir, "test")
+			require.NoError(t, err)
+			createFile = func(profileName string) (*os.File, error) {
+				f, err := os.Create(filepath.Join(filePath, tc.profileName))
+				return f, err
+			}
+			defer os.RemoveAll(filePath)
+			isProfileLoaded = func(profileName string) (bool, error) {
+				return tc.isLoadedResponse, tc.isLoadedError
+			}
+			loadPath = func(profile string) error {
+				return tc.loadError
+			}
+			err = LoadDefaultProfile(tc.profileName)
+			if tc.loadError == nil {
+				assert.Equal(t, tc.expectedError, err)
+			} else {
+				assert.Error(t, err)
+			}
+		})
+	}
+}

ecs-init/config/common.go

@@ -104,6 +104,11 @@ const (
 	// defaultCredentialsFetcherSocketPath is set to /var/credentials-fetcher/socket/credentials_fetcher.sock
 	// in case path is not passed in the env variable
 	DefaultCredentialsFetcherSocketPath = "/var/credentials-fetcher/socket/credentials_fetcher.sock"
+
+	// ECSAgentAppArmorProfileNameEnvVar specifies the AppArmor profile name to use. Only applies
+	// on AppArmor-enabled platforms (such as Ubuntu and Debian).
+	ECSAgentAppArmorProfileNameEnvVar  = "ECS_AGENT_APPARMOR_PROFILE"
+	ECSAgentAppArmorDefaultProfileName = "ecs-agent-default"
 )
 
 // partitionBucketRegion provides the "partitional" bucket region
@@ -249,7 +254,7 @@ func CgroupMountpoint() string {
 
 // MountDirectoryEBS returns the location on disk where EBS volumes will be mounted
 func MountDirectoryEBS() string {
-       return directoryPrefix + "/mnt/ecs/ebs"
+	return directoryPrefix + "/mnt/ecs/ebs"
 }
 
 // HostCertsDirPath() returns the CA store path on the host
@@ -336,6 +341,15 @@ func RunningInExternal() bool {
 	return envVar == "true"
 }
 
+// ECSAgentApparmorProfileName returns the name of the AppArmor profile to use.
+func ECSAgentAppArmorProfileName() string {
+	envVar := os.Getenv(ECSAgentAppArmorProfileNameEnvVar)
+	if len(strings.TrimSpace(envVar)) == 0 {
+		return ECSAgentAppArmorDefaultProfileName
+	}
+	return envVar
+}
+
 func agentArtifactName(version string, arch string) (string, error) {
 	var interpose string
 	switch arch {

ecs-init/config/common_test.go

@@ -50,6 +50,16 @@ func TestDockerUnixSocketWithDockerHost(t *testing.T) {
 	}
 }
 
+func TestECSAgentAppArmorProfileName(t *testing.T) {
+	profile := ECSAgentAppArmorProfileName()
+	assert.Equal(t, profile, "ecs-agent-default")
+
+	os.Setenv(ECSAgentAppArmorProfileNameEnvVar, "docker-default")
+	defer os.Unsetenv(ECSAgentAppArmorProfileNameEnvVar)
+	profile = ECSAgentAppArmorProfileName()
+	assert.Equal(t, profile, "docker-default")
+}
+
 func TestGetAgentPartitionBucketRegion(t *testing.T) {
 	testCases := []struct {
 		region      string

ecs-init/config/release.go

@@ -1,6 +1,3 @@
-//go:build !development
-// +build !development
-
 // Copyright 2015 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License"). You may

ecs-init/docker/docker_config.go

@@ -14,7 +14,10 @@
 package docker
 
 import (
+	"fmt"
+
 	"github.com/aws/amazon-ecs-agent/ecs-init/config"
+	ctrdapparmor "github.com/containerd/containerd/pkg/apparmor"
 	godocker "github.com/fsouza/go-dockerclient"
 )
 
@@ -62,6 +65,10 @@ func createHostConfig(binds []string) *godocker.HostConfig {
 		Init:        true,
 	}
 
+	if ctrdapparmor.HostSupports() {
+		hostConfig.SecurityOpt = []string{fmt.Sprintf("apparmor:%s", config.ECSAgentAppArmorProfileName())}
+	}
+
 	if config.RunPrivileged() {
 		hostConfig.Privileged = true
 	}