moby/daemon/create_unix.go
Brian Goff fc7b904dce Add new HostConfig field, Mounts.
`Mounts` allows users to specify in a much safer way the volumes they
want to use in the container.
This replaces `Binds` and `Volumes`, which both still exist, but
`Mounts` and `Binds`/`Volumes` are exclussive.
The CLI will continue to use `Binds` and `Volumes` due to concerns with
parsing the volume specs on the client side and cross-platform support
(for now).

The new API follows exactly the services mount API.

Example usage of `Mounts`:

```
$ curl -XPOST localhost:2375/containers/create -d '{
  "Image": "alpine:latest",
  "HostConfig": {
    "Mounts": [{
      "Type": "Volume",
      "Target": "/foo"
      },{
      "Type": "bind",
      "Source": "/var/run/docker.sock",
      "Target": "/var/run/docker.sock",
      },{
      "Type": "volume",
      "Name": "important_data",
      "Target": "/var/data",
      "ReadOnly": true,
      "VolumeOptions": {
	"DriverConfig": {
	  Name: "awesomeStorage",
	  Options: {"size": "10m"},
	  Labels: {"some":"label"}
	}
      }]
    }
}'
```

There are currently 2 types of mounts:

  - **bind**: Paths on the host that get mounted into the
    container. Paths must exist prior to creating the container.
  - **volume**: Volumes that persist after the
    container is removed.

Not all fields are available in each type, and validation is done to
ensure these fields aren't mixed up between types.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
2016-09-13 09:55:35 -04:00

81 lines
2.3 KiB
Go

// +build !windows
package daemon
import (
"fmt"
"os"
"path/filepath"
"github.com/Sirupsen/logrus"
containertypes "github.com/docker/docker/api/types/container"
mounttypes "github.com/docker/docker/api/types/mount"
"github.com/docker/docker/container"
"github.com/docker/docker/pkg/stringid"
"github.com/opencontainers/runc/libcontainer/label"
)
// createContainerPlatformSpecificSettings performs platform specific container create functionality
func (daemon *Daemon) createContainerPlatformSpecificSettings(container *container.Container, config *containertypes.Config, hostConfig *containertypes.HostConfig) error {
if err := daemon.Mount(container); err != nil {
return err
}
defer daemon.Unmount(container)
rootUID, rootGID := daemon.GetRemappedUIDGID()
if err := container.SetupWorkingDirectory(rootUID, rootGID); err != nil {
return err
}
for spec := range config.Volumes {
name := stringid.GenerateNonCryptoID()
destination := filepath.Clean(spec)
// Skip volumes for which we already have something mounted on that
// destination because of a --volume-from.
if container.IsDestinationMounted(destination) {
continue
}
path, err := container.GetResourcePath(destination)
if err != nil {
return err
}
stat, err := os.Stat(path)
if err == nil && !stat.IsDir() {
return fmt.Errorf("cannot mount volume over existing file, file exists %s", path)
}
v, err := daemon.volumes.CreateWithRef(name, hostConfig.VolumeDriver, container.ID, nil, nil)
if err != nil {
return err
}
if err := label.Relabel(v.Path(), container.MountLabel, true); err != nil {
return err
}
container.AddMountPointWithVolume(destination, v, true)
}
return daemon.populateVolumes(container)
}
// populateVolumes copies data from the container's rootfs into the volume for non-binds.
// this is only called when the container is created.
func (daemon *Daemon) populateVolumes(c *container.Container) error {
for _, mnt := range c.MountPoints {
if mnt.Volume == nil {
continue
}
if mnt.Type != mounttypes.TypeVolume || !mnt.CopyData {
continue
}
logrus.Debugf("copying image data from %s:%s, to %s", c.ID, mnt.Destination, mnt.Name)
if err := c.CopyImagePathContent(mnt.Volume, mnt.Destination); err != nil {
return err
}
}
return nil
}