Update restrictions for better handling of mounts

This also cleans up some of the left over restriction paths code from
before.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

daemon/execdriver/lxc/driver.go

@@ -2,12 +2,6 @@ package lxc
 
 import (
 	"fmt"
-	"github.com/dotcloud/docker/daemon/execdriver"
-	"github.com/dotcloud/docker/pkg/cgroups"
-	"github.com/dotcloud/docker/pkg/label"
-	"github.com/dotcloud/docker/pkg/libcontainer/security/restrict"
-	"github.com/dotcloud/docker/pkg/system"
-	"github.com/dotcloud/docker/utils"
 	"io/ioutil"
 	"log"
 	"os"
@@ -18,6 +12,13 @@ import (
 	"strings"
 	"syscall"
 	"time"
+
+	"github.com/dotcloud/docker/daemon/execdriver"
+	"github.com/dotcloud/docker/pkg/cgroups"
+	"github.com/dotcloud/docker/pkg/label"
+	"github.com/dotcloud/docker/pkg/libcontainer/security/restrict"
+	"github.com/dotcloud/docker/pkg/system"
+	"github.com/dotcloud/docker/utils"
 )
 
 const DriverName = "lxc"
@@ -27,31 +28,26 @@ func init() {
 		if err := setupEnv(args); err != nil {
 			return err
 		}
-
 		if err := setupHostname(args); err != nil {
 			return err
 		}
-
 		if err := setupNetworking(args); err != nil {
 			return err
 		}
-
-		if err := restrict.Restrict("/", "/empty"); err != nil {
-			return err
+		if !args.Privileged {
+			if err := restrict.Restrict(); err != nil {
+				return err
+			}
 		}
-
 		if err := setupCapabilities(args); err != nil {
 			return err
 		}
-
 		if err := setupWorkingDirectory(args); err != nil {
 			return err
 		}
-
 		if err := system.CloseFdsFrom(3); err != nil {
 			return err
 		}
-
 		if err := changeUser(args); err != nil {
 			return err
 		}
@@ -69,10 +65,9 @@ func init() {
 }
 
 type driver struct {
-	root            string // root path for the driver to use
-	apparmor        bool
-	sharedRoot      bool
-	restrictionPath string
+	root       string // root path for the driver to use
+	apparmor   bool
+	sharedRoot bool
 }
 
 func NewDriver(root string, apparmor bool) (*driver, error) {
@@ -80,15 +75,10 @@ func NewDriver(root string, apparmor bool) (*driver, error) {
 	if err := linkLxcStart(root); err != nil {
 		return nil, err
 	}
-	restrictionPath := filepath.Join(root, "empty")
-	if err := os.MkdirAll(restrictionPath, 0700); err != nil {
-		return nil, err
-	}
 	return &driver{
-		apparmor:        apparmor,
-		root:            root,
-		sharedRoot:      rootIsShared(),
-		restrictionPath: restrictionPath,
+		apparmor:   apparmor,
+		root:       root,
+		sharedRoot: rootIsShared(),
 	}, nil
 }
 
@@ -419,16 +409,14 @@ func (d *driver) generateLXCConfig(c *execdriver.Command) (string, error) {
 
 	if err := LxcTemplateCompiled.Execute(fo, struct {
 		*execdriver.Command
-		AppArmor          bool
-		ProcessLabel      string
-		MountLabel        string
-		RestrictionSource string
+		AppArmor     bool
+		ProcessLabel string
+		MountLabel   string
 	}{
-		Command:           c,
-		AppArmor:          d.apparmor,
-		ProcessLabel:      process,
-		MountLabel:        mount,
-		RestrictionSource: d.restrictionPath,
+		Command:      c,
+		AppArmor:     d.apparmor,
+		ProcessLabel: process,
+		MountLabel:   mount,
 	}); err != nil {
 		return "", err
 	}

daemon/execdriver/lxc/lxc_template.go

@@ -1,10 +1,11 @@
 package lxc
 
 import (
-	"github.com/dotcloud/docker/daemon/execdriver"
-	"github.com/dotcloud/docker/pkg/label"
 	"strings"
 	"text/template"
+
+	"github.com/dotcloud/docker/daemon/execdriver"
+	"github.com/dotcloud/docker/pkg/label"
 )
 
 const LxcTemplate = `
@@ -110,13 +111,6 @@ lxc.aa_profile = unconfined
 {{else}}
 # Let AppArmor normal confinement take place (i.e., not unconfined)
 {{end}}
-{{else}}
-# Restrict access to some stuff in /proc. Note that /proc is already mounted
-# read-only, so we don't need to bother about things that are just dangerous
-# to write to (like sysrq-trigger). Also, recent kernels won't let a container
-# peek into /proc/kcore, but let's cater for people who might run Docker on
-# older kernels. Just in case.
-lxc.mount.entry = {{escapeFstabSpaces $ROOTFS}}/dev/null {{escapeFstabSpaces $ROOTFS}}/proc/kcore none bind,ro 0 0
 {{end}}
 
 # limits

daemon/execdriver/native/create.go

@@ -24,7 +24,7 @@ func (d *driver) createContainer(c *execdriver.Command) (*libcontainer.Container
 	container.Cgroups.Name = c.ID
 	// check to see if we are running in ramdisk to disable pivot root
 	container.NoPivotRoot = os.Getenv("DOCKER_RAMDISK") != ""
-	container.Context["restriction_path"] = d.restrictionPath
+	container.Context["restrictions"] = "true"
 
 	if err := d.createNetwork(container, c); err != nil {
 		return nil, err
@@ -84,7 +84,7 @@ func (d *driver) setPrivileged(container *libcontainer.Container) error {
 	}
 	container.Cgroups.DeviceAccess = true
 
-	delete(container.Context, "restriction_path")
+	delete(container.Context, "restrictions")
 
 	if apparmor.IsEnabled() {
 		container.Context["apparmor_profile"] = "unconfined"

daemon/execdriver/native/driver.go

@@ -57,7 +57,6 @@ type driver struct {
 	root             string
 	initPath         string
 	activeContainers map[string]*exec.Cmd
-	restrictionPath  string
 }
 
 func NewDriver(root, initPath string) (*driver, error) {
@@ -68,14 +67,8 @@ func NewDriver(root, initPath string) (*driver, error) {
 	if err := apparmor.InstallDefaultProfile(filepath.Join(root, "../..", BackupApparmorProfilePath)); err != nil {
 		return nil, err
 	}
-	restrictionPath := filepath.Join(root, "empty")
-	if err := os.MkdirAll(restrictionPath, 0700); err != nil {
-		return nil, err
-	}
-
 	return &driver{
 		root:             root,
-		restrictionPath:  restrictionPath,
 		initPath:         initPath,
 		activeContainers: make(map[string]*exec.Cmd),
 	}, nil