diff --git a/docs/reference/commandline/run.md b/docs/reference/commandline/run.md
index fc4a9e5a3a..eb0eba9fa6 100644
--- a/docs/reference/commandline/run.md
+++ b/docs/reference/commandline/run.md
@@ -264,9 +264,9 @@ Docker daemon.
For in-depth information about volumes, refer to [manage data in containers](https://docs.docker.com/engine/tutorials/dockervolumes/)
-### Add bin-mounts or volumes using the --mounts flag
+### Add bin-mounts or volumes using the --mount flag
-The `--mounts` flag allows you to mount volumes, host-directories and `tmpfs`
+The `--mount` flag allows you to mount volumes, host-directories and `tmpfs`
mounts in a container.
The `--mount` flag supports most options that are supported by the `-v` or the
diff --git a/docs/reference/commandline/service_create.md b/docs/reference/commandline/service_create.md
index 4d95ce96a2..3c16c20209 100644
--- a/docs/reference/commandline/service_create.md
+++ b/docs/reference/commandline/service_create.md
@@ -172,6 +172,8 @@ or write from files or directories on other containers or the host operating
system. These types are _data volumes_ (often referred to simply as volumes) and
_bind-mounts_.
+Additionally, Docker also supports tmpfs mounts.
+
A **bind-mount** makes a file or directory on the host available to the
container it is mounted within. A bind-mount may be either read-only or
read-write. For example, a container might share its host's DNS information by
@@ -188,6 +190,8 @@ shared between a container and the host machine, as well as between multiple
containers. Docker uses a _volume driver_ to create, manage, and mount volumes.
You can back up or restore volumes using Docker commands.
+A **tmpfs** mounts a tmpfs inside a container for volatile data.
+
Consider a situation where your image starts a lightweight web server. You could
use that image as a base image, copy in your website's HTML files, and package
that into another image. Each time your website changed, you'd need to update
@@ -204,8 +208,8 @@ volumes in a service:
| Option | Required | Description
|:-----------------------------------------|:--------------------------|:-----------------------------------------------------------------------------------------
-| **type** | | The type of mount, can be either `volume`, or `bind`. Defaults to `volume` if no type is specified.
- `volume`: mounts a [managed volume](volume_create.md) into the container.
- `bind`: bind-mounts a directory or file from the host into the container.
-| **src** or **source** | for `type=bind` only | - `type=volume`: `src` is an optional way to specify the name of the volume (for example, `src=my-volume`). If the named volume does not exist, it is automatically created. If no `src` is specified, the volume is assigned a random name which is guaranteed to be unique on the host, but may not be unique cluster-wide. A randomly-named volume has the same lifecycle as its container and is destroyed when the *container* is destroyed (which is upon `service update`, or when scaling or re-balancing the service).
- `type=bind`: `src` is required, and specifies an absolute path to the file or directory to bind-mount (for example, `src=/path/on/host/`). An error is produced if the file or directory does not exist.
+| **type** | | The type of mount, can be either `volume`, `bind`, or `tmpfs`. Defaults to `volume` if no type is specified.- `volume`: mounts a [managed volume](volume_create.md) into the container.
- `bind`: bind-mounts a directory or file from the host into the container.
- `tmpfs`: mount a tmpfs in the container
+| **src** or **source** | for `type=bind` only | - `type=volume`: `src` is an optional way to specify the name of the volume (for example, `src=my-volume`). If the named volume does not exist, it is automatically created. If no `src` is specified, the volume is assigned a random name which is guaranteed to be unique on the host, but may not be unique cluster-wide. A randomly-named volume has the same lifecycle as its container and is destroyed when the *container* is destroyed (which is upon `service update`, or when scaling or re-balancing the service).
- `type=bind`: `src` is required, and specifies an absolute path to the file or directory to bind-mount (for example, `src=/path/on/host/`). An error is produced if the file or directory does not exist.
- `type=tmpfs`: `src` is not supported.
| **dst** or **destination** or **target** | yes | Mount path inside the container, for example `/some/path/in/container/`. If the path does not exist in the container's filesystem, the Engine creates a directory at the specified location before mounting the volume or bind-mount.
| **readonly** or **ro** | | The Engine mounts binds and volumes `read-write` unless `readonly` option is given when mounting the bind or volume.
- `true` or `1` or no value: Mounts the bind or volume read-only.
- `false` or `0`: Mounts the bind or volume read-write.
@@ -256,6 +260,14 @@ The following options can only be used for named volumes (`type=volume`);
| **volume-nocopy** | By default, if you attach an empty volume to a container, and files or directories already existed at the mount-path in the container (`dst`), the Engine copies those files and directories into the volume, allowing the host to access them. Set `volume-nocopy` to disables copying files from the container's filesystem to the volume and mount the empty volume.
A value is optional:- `true` or `1`: Default if you do not provide a value. Disables copying.
- `false` or `0`: Enables copying.
| **volume-opt** | Options specific to a given volume driver, which will be passed to the driver when creating the volume. Options are provided as a comma-separated list of key/value pairs, for example, `volume-opt=some-option=some-value,some-other-option=some-other-value`. For available options for a given driver, refer to that driver's documentation.
+#### Options for tmpfs
+The following options can only be used for tmpfs mounts (`type=tmpfs`);
+
+| Option | Description
+|:----------------------|:--------------------------------------------------------------------------------------------------------------------
+| **tmpfs-size** | Size of the tmpfs mount in bytes. Unlimited by default in Linux.
+| **tmpfs-mode** | File mode of the tmpfs in octal. (e.g. `"700"` or `"0700"`.) Defaults to ``"1777"`` in Linux.
+
#### Differences between "--mount" and "--volume"
The `--mount` flag supports most options that are supported by the `-v`
diff --git a/opts/mount.go b/opts/mount.go
index b6fccade18..ce6383ddca 100644
--- a/opts/mount.go
+++ b/opts/mount.go
@@ -3,10 +3,12 @@ package opts
import (
"encoding/csv"
"fmt"
+ "os"
"strconv"
"strings"
mounttypes "github.com/docker/docker/api/types/mount"
+ "github.com/docker/go-units"
)
// MountOpt is a Value type for parsing mounts
@@ -43,6 +45,13 @@ func (m *MountOpt) Set(value string) error {
return mount.BindOptions
}
+ tmpfsOptions := func() *mounttypes.TmpfsOptions {
+ if mount.TmpfsOptions == nil {
+ mount.TmpfsOptions = new(mounttypes.TmpfsOptions)
+ }
+ return mount.TmpfsOptions
+ }
+
setValueOnMap := func(target map[string]string, value string) {
parts := strings.SplitN(value, "=", 2)
if len(parts) == 1 {
@@ -102,6 +111,18 @@ func (m *MountOpt) Set(value string) error {
volumeOptions().DriverConfig.Options = make(map[string]string)
}
setValueOnMap(volumeOptions().DriverConfig.Options, value)
+ case "tmpfs-size":
+ sizeBytes, err := units.RAMInBytes(value)
+ if err != nil {
+ return fmt.Errorf("invalid value for %s: %s", key, value)
+ }
+ tmpfsOptions().SizeBytes = sizeBytes
+ case "tmpfs-mode":
+ ui64, err := strconv.ParseUint(value, 8, 32)
+ if err != nil {
+ return fmt.Errorf("invalid value for %s: %s", key, value)
+ }
+ tmpfsOptions().Mode = os.FileMode(ui64)
default:
return fmt.Errorf("unexpected key '%s' in '%s'", key, field)
}
@@ -115,11 +136,14 @@ func (m *MountOpt) Set(value string) error {
return fmt.Errorf("target is required")
}
- if mount.Type == mounttypes.TypeBind && mount.VolumeOptions != nil {
- return fmt.Errorf("cannot mix 'volume-*' options with mount type '%s'", mounttypes.TypeBind)
+ if mount.VolumeOptions != nil && mount.Type != mounttypes.TypeVolume {
+ return fmt.Errorf("cannot mix 'volume-*' options with mount type '%s'", mount.Type)
}
- if mount.Type == mounttypes.TypeVolume && mount.BindOptions != nil {
- return fmt.Errorf("cannot mix 'bind-*' options with mount type '%s'", mounttypes.TypeVolume)
+ if mount.BindOptions != nil && mount.Type != mounttypes.TypeBind {
+ return fmt.Errorf("cannot mix 'bind-*' options with mount type '%s'", mount.Type)
+ }
+ if mount.TmpfsOptions != nil && mount.Type != mounttypes.TypeTmpfs {
+ return fmt.Errorf("cannot mix 'tmpfs-*' options with mount type '%s'", mount.Type)
}
m.values = append(m.values, mount)
diff --git a/opts/mount_test.go b/opts/mount_test.go
index 28c551bcc6..59606c38e2 100644
--- a/opts/mount_test.go
+++ b/opts/mount_test.go
@@ -1,6 +1,7 @@
package opts
import (
+ "os"
"testing"
mounttypes "github.com/docker/docker/api/types/mount"
@@ -151,3 +152,33 @@ func TestMountOptTypeConflict(t *testing.T) {
assert.Error(t, m.Set("type=bind,target=/foo,source=/foo,volume-nocopy=true"), "cannot mix")
assert.Error(t, m.Set("type=volume,target=/foo,source=/foo,bind-propagation=rprivate"), "cannot mix")
}
+
+func TestMountOptSetTmpfsNoError(t *testing.T) {
+ for _, testcase := range []string{
+ // tests several aliases that should have same result.
+ "type=tmpfs,target=/target,tmpfs-size=1m,tmpfs-mode=0700",
+ "type=tmpfs,target=/target,tmpfs-size=1MB,tmpfs-mode=700",
+ } {
+ var mount MountOpt
+
+ assert.NilError(t, mount.Set(testcase))
+
+ mounts := mount.Value()
+ assert.Equal(t, len(mounts), 1)
+ assert.DeepEqual(t, mounts[0], mounttypes.Mount{
+ Type: mounttypes.TypeTmpfs,
+ Target: "/target",
+ TmpfsOptions: &mounttypes.TmpfsOptions{
+ SizeBytes: 1024 * 1024, // not 1000 * 1000
+ Mode: os.FileMode(0700),
+ },
+ })
+ }
+}
+
+func TestMountOptSetTmpfsError(t *testing.T) {
+ var m MountOpt
+ assert.Error(t, m.Set("type=tmpfs,target=/foo,tmpfs-size=foo"), "invalid value for tmpfs-size")
+ assert.Error(t, m.Set("type=tmpfs,target=/foo,tmpfs-mode=foo"), "invalid value for tmpfs-mode")
+ assert.Error(t, m.Set("type=tmpfs"), "target is required")
+}