dotcloud/docker

package containerd

import (
    "context"
    "errors"
    "fmt"

    "github.com/containerd/log"
    "github.com/docker/docker/container"
)

// Mount mounts the container filesystem in a temporary location, use defer imageService.Unmount
// to unmount the filesystem when calling this
func (i *ImageService) Mount(ctx context.Context, container *container.Container) error {
    snapshotter := i.client.SnapshotService(container.Driver)
    mounts, err := snapshotter.Mounts(ctx, container.ID)
    if err != nil {
        return err
    }

    var root string
    if root, err = i.refCountMounter.Mount(mounts, container.ID); err != nil {
        return fmt.Errorf("failed to mount %s: %w", root, err)
    }

    log.G(ctx).WithField("container", container.ID).Debugf("container mounted via snapshotter: %v", root)

    container.BaseFS = root
    return nil
}

// Unmount unmounts the container base filesystem
func (i *ImageService) Unmount(ctx context.Context, container *container.Container) error {
    baseFS := container.BaseFS
    if baseFS == "" {
        target, err := i.refCountMounter.Mounted(container.ID)
        if err != nil {
            log.G(ctx).WithField("containerID", container.ID).Warn("failed to determine if container is already mounted")
        }
        if target == "" {
            return errors.New("BaseFS is empty")
        }
        baseFS = target
    }

    if err := i.refCountMounter.Unmount(baseFS); err != nil {
        log.G(ctx).WithField("container", container.ID).WithError(err).Error("error unmounting container")
        return fmt.Errorf("failed to unmount %s: %w", baseFS, err)
    }

    return nil
}