mount: add BindOptions.NonRecursive (API v1.40)

This allows non-recursive bind-mount, i.e. mount(2) with "bind" rather than "rbind".

Swarm-mode will be supported in a separate PR because of mutual vendoring.

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

api/server/router/container/container_routes.go

@@ -465,6 +465,16 @@ func (s *containerRouter) postContainersCreate(ctx context.Context, w http.Respo
 		hostConfig.AutoRemove = false
 	}
 
+	// When using API 1.39 and under, BindOptions.NonRecursive should be ignored because it
+	// was added in API 1.40.
+	if hostConfig != nil && versions.LessThan(version, "1.40") {
+		for _, m := range hostConfig.Mounts {
+			if bo := m.BindOptions; bo != nil {
+				bo.NonRecursive = false
+			}
+		}
+	}
+
 	ccr, err := s.backend.ContainerCreate(types.ContainerCreateConfig{
 		Name:             name,
 		Config:           config,

api/swagger.yaml

@@ -265,6 +265,10 @@ definitions:
               - "rshared"
               - "slave"
               - "rslave"
+          NonRecursive:
+            description: "Disable recursive bind mount."
+            type: "boolean"
+            default: false
       VolumeOptions:
         description: "Optional configuration for the `volume` type."
         type: "object"

api/types/mount/mount.go

@@ -79,7 +79,8 @@ const (
 
 // BindOptions defines options specific to mounts of type "bind".
 type BindOptions struct {
-	Propagation Propagation `json:",omitempty"`
+	Propagation  Propagation `json:",omitempty"`
+	NonRecursive bool        `json:",omitempty"`
 }
 
 // VolumeOptions represents the options for a mount of type volume.

container/mounts_unix.go

@@ -4,9 +4,10 @@ package container // import "github.com/docker/docker/container"
 
 // Mount contains information for a mount operation.
 type Mount struct {
-	Source      string `json:"source"`
+	Source       string `json:"source"`
-	Destination string `json:"destination"`
+	Destination  string `json:"destination"`
-	Writable    bool   `json:"writable"`
+	Writable     bool   `json:"writable"`
-	Data        string `json:"data"`
+	Data         string `json:"data"`
-	Propagation string `json:"mountpropagation"`
+	Propagation  string `json:"mountpropagation"`
+	NonRecursive bool   `json:"nonrecursive"`
 }

daemon/cluster/convert/container.go

@@ -321,6 +321,12 @@ func containerToGRPC(c *types.ContainerSpec) (*swarmapi.ContainerSpec, error) {
 			} else if string(m.BindOptions.Propagation) != "" {
 				return nil, fmt.Errorf("invalid MountPropagation: %q", m.BindOptions.Propagation)
 			}
+
+			if m.BindOptions.NonRecursive {
+				// TODO(AkihiroSuda): NonRecursive is unsupported for Swarm-mode now because of mutual vendoring
+				// across moby and swarmkit. Will be available soon after the moby PR gets merged.
+				return nil, fmt.Errorf("invalid NonRecursive: %q", m.BindOptions.Propagation)
+			}
 		}
 
 		if m.VolumeOptions != nil {

daemon/oci_linux.go

@@ -565,7 +565,11 @@ func setMounts(daemon *Daemon, s *specs.Spec, c *container.Container, mounts []c
 			}
 		}
 
-		opts := []string{"rbind"}
+		bindMode := "rbind"
+		if m.NonRecursive {
+			bindMode = "bind"
+		}
+		opts := []string{bindMode}
 		if !m.Writable {
 			opts = append(opts, "ro")
 		}

daemon/volumes_unix.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"strings"
 
+	mounttypes "github.com/docker/docker/api/types/mount"
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/pkg/fileutils"
 	"github.com/docker/docker/pkg/mount"
@@ -58,6 +59,9 @@ func (daemon *Daemon) setupMounts(c *container.Container) ([]container.Mount, er
 				Writable:    m.RW,
 				Propagation: string(m.Propagation),
 			}
+			if m.Spec.Type == mounttypes.TypeBind && m.Spec.BindOptions != nil {
+				mnt.NonRecursive = m.Spec.BindOptions.NonRecursive
+			}
 			if m.Volume != nil {
 				attributes := map[string]string{
 					"driver":      m.Volume.DriverName(),
@@ -129,11 +133,15 @@ func (daemon *Daemon) mountVolumes(container *container.Container) error {
 			return err
 		}
 
-		opts := "rbind,ro"
+		bindMode := "rbind"
-		if m.Writable {
+		if m.NonRecursive {
-			opts = "rbind,rw"
+			bindMode = "bind"
 		}
-
+		writeMode := "ro"
+		if m.Writable {
+			writeMode = "rw"
+		}
+		opts := strings.Join([]string{bindMode, writeMode}, ",")
 		if err := mount.Mount(m.Source, dest, bindMountType, opts); err != nil {
 			return err
 		}

docs/api/version-history.md

@@ -27,6 +27,8 @@ keywords: "API, Docker, rcli, REST, documentation"
   on the node.label. The format of the label filter is `node.label=<key>`/`node.label=<key>=<value>`
   to return those with the specified labels, or `node.label!=<key>`/`node.label!=<key>=<value>`
   to return those without the specified labels.
+* `POST /containers/create`, `GET /containers/{id}/json`, and `GET /containers/json` now supports
+  `BindOptions.NonRecursive`.
 
 ## V1.39 API changes
 

integration/container/mounts_linux_test.go

@@ -5,17 +5,22 @@ import (
 	"fmt"
 	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/container"
+	containertypes "github.com/docker/docker/api/types/container"
-	"github.com/docker/docker/api/types/mount"
+	mounttypes "github.com/docker/docker/api/types/mount"
 	"github.com/docker/docker/api/types/network"
+	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/docker/client"
+	"github.com/docker/docker/integration/internal/container"
 	"github.com/docker/docker/internal/test/request"
+	"github.com/docker/docker/pkg/mount"
 	"github.com/docker/docker/pkg/system"
 	"gotest.tools/assert"
 	is "gotest.tools/assert/cmp"
 	"gotest.tools/fs"
+	"gotest.tools/poll"
 	"gotest.tools/skip"
 )
 
@@ -32,11 +37,11 @@ func TestContainerNetworkMountsNoChown(t *testing.T) {
 
 	tmpNWFileMount := tmpDir.Join("nwfile")
 
-	config := container.Config{
+	config := containertypes.Config{
 		Image: "busybox",
 	}
-	hostConfig := container.HostConfig{
+	hostConfig := containertypes.HostConfig{
-		Mounts: []mount.Mount{
+		Mounts: []mounttypes.Mount{
 			{
 				Type:   "bind",
 				Source: tmpNWFileMount,
@@ -93,39 +98,39 @@ func TestMountDaemonRoot(t *testing.T) {
 
 	for _, test := range []struct {
 		desc        string
-		propagation mount.Propagation
+		propagation mounttypes.Propagation
-		expected    mount.Propagation
+		expected    mounttypes.Propagation
 	}{
 		{
 			desc:        "default",
 			propagation: "",
-			expected:    mount.PropagationRSlave,
+			expected:    mounttypes.PropagationRSlave,
 		},
 		{
 			desc:        "private",
-			propagation: mount.PropagationPrivate,
+			propagation: mounttypes.PropagationPrivate,
 		},
 		{
 			desc:        "rprivate",
-			propagation: mount.PropagationRPrivate,
+			propagation: mounttypes.PropagationRPrivate,
 		},
 		{
 			desc:        "slave",
-			propagation: mount.PropagationSlave,
+			propagation: mounttypes.PropagationSlave,
 		},
 		{
 			desc:        "rslave",
-			propagation: mount.PropagationRSlave,
+			propagation: mounttypes.PropagationRSlave,
-			expected:    mount.PropagationRSlave,
+			expected:    mounttypes.PropagationRSlave,
 		},
 		{
 			desc:        "shared",
-			propagation: mount.PropagationShared,
+			propagation: mounttypes.PropagationShared,
 		},
 		{
 			desc:        "rshared",
-			propagation: mount.PropagationRShared,
+			propagation: mounttypes.PropagationRShared,
-			expected:    mount.PropagationRShared,
+			expected:    mounttypes.PropagationRShared,
 		},
 	} {
 		t.Run(test.desc, func(t *testing.T) {
@@ -139,26 +144,26 @@ func TestMountDaemonRoot(t *testing.T) {
 			bindSpecRoot := info.DockerRootDir + ":" + "/foo" + propagationSpec
 			bindSpecSub := filepath.Join(info.DockerRootDir, "containers") + ":/foo" + propagationSpec
 
-			for name, hc := range map[string]*container.HostConfig{
+			for name, hc := range map[string]*containertypes.HostConfig{
 				"bind root":    {Binds: []string{bindSpecRoot}},
 				"bind subpath": {Binds: []string{bindSpecSub}},
 				"mount root": {
-					Mounts: []mount.Mount{
+					Mounts: []mounttypes.Mount{
 						{
-							Type:        mount.TypeBind,
+							Type:        mounttypes.TypeBind,
 							Source:      info.DockerRootDir,
 							Target:      "/foo",
-							BindOptions: &mount.BindOptions{Propagation: test.propagation},
+							BindOptions: &mounttypes.BindOptions{Propagation: test.propagation},
 						},
 					},
 				},
 				"mount subpath": {
-					Mounts: []mount.Mount{
+					Mounts: []mounttypes.Mount{
 						{
-							Type:        mount.TypeBind,
+							Type:        mounttypes.TypeBind,
 							Source:      filepath.Join(info.DockerRootDir, "containers"),
 							Target:      "/foo",
-							BindOptions: &mount.BindOptions{Propagation: test.propagation},
+							BindOptions: &mounttypes.BindOptions{Propagation: test.propagation},
 						},
 					},
 				},
@@ -167,7 +172,7 @@ func TestMountDaemonRoot(t *testing.T) {
 					hc := hc
 					t.Parallel()
 
-					c, err := client.ContainerCreate(ctx, &container.Config{
+					c, err := client.ContainerCreate(ctx, &containertypes.Config{
 						Image: "busybox",
 						Cmd:   []string{"true"},
 					}, hc, nil, "")
@@ -206,3 +211,58 @@ func TestMountDaemonRoot(t *testing.T) {
 		})
 	}
 }
+
+func TestContainerBindMountNonRecursive(t *testing.T) {
+	skip.If(t, testEnv.DaemonInfo.OSType != "linux" || testEnv.IsRemoteDaemon())
+	skip.If(t, versions.LessThan(testEnv.DaemonAPIVersion(), "1.40"), "BindOptions.NonRecursive requires API v1.40")
+
+	defer setupTest(t)()
+
+	tmpDir1 := fs.NewDir(t, "tmpdir1", fs.WithMode(0755),
+		fs.WithDir("mnt", fs.WithMode(0755)))
+	defer tmpDir1.Remove()
+	tmpDir1Mnt := filepath.Join(tmpDir1.Path(), "mnt")
+	tmpDir2 := fs.NewDir(t, "tmpdir2", fs.WithMode(0755),
+		fs.WithFile("file", "should not be visible when NonRecursive", fs.WithMode(0644)))
+	defer tmpDir2.Remove()
+
+	err := mount.Mount(tmpDir2.Path(), tmpDir1Mnt, "none", "bind,ro")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := mount.Unmount(tmpDir1Mnt); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// implicit is recursive (NonRecursive: false)
+	implicit := mounttypes.Mount{
+		Type:     "bind",
+		Source:   tmpDir1.Path(),
+		Target:   "/foo",
+		ReadOnly: true,
+	}
+	recursive := implicit
+	recursive.BindOptions = &mounttypes.BindOptions{
+		NonRecursive: false,
+	}
+	recursiveVerifier := []string{"test", "-f", "/foo/mnt/file"}
+	nonRecursive := implicit
+	nonRecursive.BindOptions = &mounttypes.BindOptions{
+		NonRecursive: true,
+	}
+	nonRecursiveVerifier := []string{"test", "!", "-f", "/foo/mnt/file"}
+
+	ctx := context.Background()
+	client := request.NewAPIClient(t)
+	containers := []string{
+		container.Run(t, ctx, client, container.WithMount(implicit), container.WithCmd(recursiveVerifier...)),
+		container.Run(t, ctx, client, container.WithMount(recursive), container.WithCmd(recursiveVerifier...)),
+		container.Run(t, ctx, client, container.WithMount(nonRecursive), container.WithCmd(nonRecursiveVerifier...)),
+	}
+
+	for _, c := range containers {
+		poll.WaitOn(t, container.IsSuccessful(ctx, client, c), poll.WithDelay(100*time.Millisecond))
+	}
+}

integration/internal/container/ops.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	containertypes "github.com/docker/docker/api/types/container"
+	mounttypes "github.com/docker/docker/api/types/mount"
 	networktypes "github.com/docker/docker/api/types/network"
 	"github.com/docker/docker/api/types/strslice"
 	"github.com/docker/go-connections/nat"
@@ -68,6 +69,13 @@ func WithWorkingDir(dir string) func(*TestContainerConfig) {
 	}
 }
 
+// WithMount adds an mount
+func WithMount(m mounttypes.Mount) func(*TestContainerConfig) {
+	return func(c *TestContainerConfig) {
+		c.HostConfig.Mounts = append(c.HostConfig.Mounts, m)
+	}
+}
+
 // WithVolume sets the volume of the container
 func WithVolume(name string) func(*TestContainerConfig) {
 	return func(c *TestContainerConfig) {

integration/internal/container/states.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/docker/docker/client"
+	"github.com/pkg/errors"
 	"gotest.tools/poll"
 )
 
@@ -39,3 +40,20 @@ func IsInState(ctx context.Context, client client.APIClient, containerID string,
 		return poll.Continue("waiting for container to be one of (%s), currently %s", strings.Join(state, ", "), inspect.State.Status)
 	}
 }
+
+// IsSuccessful verifies state.Status == "exited" && state.ExitCode == 0
+func IsSuccessful(ctx context.Context, client client.APIClient, containerID string) func(log poll.LogT) poll.Result {
+	return func(log poll.LogT) poll.Result {
+		inspect, err := client.ContainerInspect(ctx, containerID)
+		if err != nil {
+			return poll.Error(err)
+		}
+		if inspect.State.Status == "exited" {
+			if inspect.State.ExitCode == 0 {
+				return poll.Success()
+			}
+			return poll.Error(errors.Errorf("expected exit code 0, got %d", inspect.State.ExitCode))
+		}
+		return poll.Continue("waiting for container to be \"exited\", currently %s", inspect.State.Status)
+	}
+}

volume/mounts/linux_parser.go

@@ -97,6 +97,9 @@ func (p *linuxParser) validateMountConfigImpl(mnt *mount.Mount, validateBindSour
 			return &errMountConfig{mnt, fmt.Errorf("must not set ReadOnly mode when using anonymous volumes")}
 		}
 	case mount.TypeTmpfs:
+		if mnt.BindOptions != nil {
+			return &errMountConfig{mnt, errExtraField("BindOptions")}
+		}
 		if len(mnt.Source) != 0 {
 			return &errMountConfig{mnt, errExtraField("Source")}
 		}