dotcloud/docker

package daemon // import "github.com/docker/docker/daemon"

import (
    "context"
    "fmt"

    containertypes "github.com/docker/docker/api/types/container"
    "github.com/docker/docker/container"
    volumemounts "github.com/docker/docker/volume/mounts"
    volumeopts "github.com/docker/docker/volume/service/opts"
)

// createContainerOSSpecificSettings performs host-OS specific container create functionality
func (daemon *Daemon) createContainerOSSpecificSettings(ctx context.Context, container *container.Container, config *containertypes.Config, hostConfig *containertypes.HostConfig) error {
    if containertypes.Isolation.IsDefault(hostConfig.Isolation) {
        // Make sure the host config has the default daemon isolation if not specified by caller.
        hostConfig.Isolation = daemon.defaultIsolation
    }
    parser := volumemounts.NewParser()
    for spec := range config.Volumes {

        mp, err := parser.ParseMountRaw(spec, hostConfig.VolumeDriver)
        if err != nil {
            return fmt.Errorf("Unrecognised volume spec: %v", err)
        }

        // Skip volumes for which we already have something mounted on that
        // destination because of a --volume-from.
        if container.IsDestinationMounted(mp.Destination) {
            continue
        }

        volumeDriver := hostConfig.VolumeDriver

        // Create the volume in the volume driver. If it doesn't exist,
        // a new one will be created.
        v, err := daemon.volumes.Create(ctx, "", volumeDriver, volumeopts.WithCreateReference(container.ID))
        if err != nil {
            return err
        }

        // FIXME Windows: This code block is present in the Linux version and
        // allows the contents to be copied to the container FS prior to it
        // being started. However, the function utilizes the FollowSymLinkInScope
        // path which does not cope with Windows volume-style file paths. There
        // is a separate effort to resolve this (@swernli), so this processing
        // is deferred for now. A case where this would be useful is when
        // a dockerfile includes a VOLUME statement, but something is created
        // in that directory during the dockerfile processing. What this means
        // on Windows for TP5 is that in that scenario, the contents will not
        // copied, but that's (somewhat) OK as HCS will bomb out soon after
        // at it doesn't support mapped directories which have contents in the
        // destination path anyway.
        //
        // Example for repro later:
        //   FROM windowsservercore
        //   RUN mkdir c:\myvol
        //   RUN copy c:\windows\system32\ntdll.dll c:\myvol
        //   VOLUME "c:\myvol"
        //
        // Then
        //   docker build -t vol .
        //   docker run -it --rm vol cmd  <-- This is where HCS will error out.
        //
        //    // never attempt to copy existing content in a container FS to a shared volume
        //    if v.DriverName() == volume.DefaultDriverName {
        //        if err := container.CopyImagePathContent(v, mp.Destination); err != nil {
        //            return err
        //        }
        //    }

        // Add it to container.MountPoints
        container.AddMountPointWithVolume(mp.Destination, &volumeWrapper{v: v, s: daemon.volumes}, mp.RW)
    }
    return nil
}