Cleanup: initializeVolume
- Use a common struct for Volumes - Split out some functionality in intializeVolume into separate functions - Removes some duplicate code - In general much easier to grok the code now Docker-DCO-1.1-Signed-off-by: Brian Goff <cpuguy83@gmail.com> (github: cpuguy83)
This commit is contained in:
Brian Goff
parent
7dbab337dd
commit
e350df5b2c
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@ -13,10 +13,24 @@ import (
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"github.com/docker/docker/pkg/symlink"
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)
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type BindMap struct {
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SrcPath string
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DstPath string
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Mode string
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type Volume struct {
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HostPath string
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VolPath string
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Mode string
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isBindMount bool
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}
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func (v *Volume) isRw() bool {
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return v.Mode == "" || strings.ToLower(v.Mode) == "rw"
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}
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func (v *Volume) isDir() (bool, error) {
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stat, err := os.Stat(v.HostPath)
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if err != nil {
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return false, err
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}
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return stat.IsDir(), nil
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}
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func prepareVolumesForContainer(container *Container) error {
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@ -122,35 +136,40 @@ func applyVolumesFrom(container *Container) error {
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return nil
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}
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func parseBindVolumeSpec(spec string) (BindMap, error) {
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func parseBindVolumeSpec(spec string) (Volume, error) {
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var (
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arr = strings.Split(spec, ":")
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err error = nil
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vol BindMap
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arr = strings.Split(spec, ":")
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vol Volume
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)
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vol.isBindMount = true
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switch len(arr) {
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case 1:
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vol.DstPath = spec
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vol.VolPath = spec
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vol.Mode = "rw"
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case 2:
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vol.SrcPath = arr[0]
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vol.DstPath = arr[1]
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vol.HostPath = arr[0]
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vol.VolPath = arr[1]
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vol.Mode = "rw"
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case 3:
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vol.SrcPath = arr[0]
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vol.DstPath = arr[1]
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vol.HostPath = arr[0]
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vol.VolPath = arr[1]
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vol.Mode = arr[2]
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default:
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err = fmt.Errorf("Invalid volume specification: %s", spec)
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return vol, fmt.Errorf("Invalid volume specification: %s", spec)
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}
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return vol, err
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if !filepath.IsAbs(vol.HostPath) {
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return vol, fmt.Errorf("cannot bind mount volume: %s volume paths must be absolute.", vol.HostPath)
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}
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return vol, nil
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}
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func getBindMap(container *Container) (map[string]BindMap, error) {
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func getBindMap(container *Container) (map[string]Volume, error) {
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var (
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// Create the requested bind mounts
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binds = make(map[string]BindMap)
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volumes = map[string]Volume{}
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// Define illegal container destinations
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illegalDsts = []string{"/", "."}
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)
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@ -158,151 +177,134 @@ func getBindMap(container *Container) (map[string]BindMap, error) {
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for _, bind := range container.hostConfig.Binds {
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vol, err := parseBindVolumeSpec(bind)
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if err != nil {
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return binds, err
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return volumes, err
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}
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// Bail if trying to mount to an illegal destination
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for _, illegal := range illegalDsts {
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if vol.DstPath == illegal {
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return nil, fmt.Errorf("Illegal bind destination: %s", vol.DstPath)
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if vol.VolPath == illegal {
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return nil, fmt.Errorf("Illegal bind destination: %s", vol.VolPath)
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}
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}
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binds[filepath.Clean(vol.DstPath)] = vol
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volumes[filepath.Clean(vol.VolPath)] = vol
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}
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return binds, nil
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return volumes, nil
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}
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func createVolumes(container *Container) error {
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binds, err := getBindMap(container)
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// Get all the bindmounts
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volumes, err := getBindMap(container)
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if err != nil {
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return err
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}
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// Create the requested volumes if they don't exist
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// Get all the rest of the volumes
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for volPath := range container.Config.Volumes {
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if err := initializeVolume(container, volPath, binds); err != nil {
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// Make sure the the volume isn't already specified as a bindmount
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if _, exists := volumes[volPath]; !exists {
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volumes[volPath] = Volume{
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VolPath: volPath,
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Mode: "rw",
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isBindMount: false,
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}
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}
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}
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for _, vol := range volumes {
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if err = vol.initialize(container); err != nil {
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return err
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}
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}
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return nil
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}
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func createVolumeHostPath(container *Container) (string, error) {
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volumesDriver := container.daemon.volumes.Driver()
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// Do not pass a container as the parameter for the volume creation.
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// The graph driver using the container's information ( Image ) to
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// create the parent.
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c, err := container.daemon.volumes.Create(nil, "", "", "", "", nil, nil)
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if err != nil {
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return "", err
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}
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hostPath, err := volumesDriver.Get(c.ID, "")
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if err != nil {
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return hostPath, fmt.Errorf("Driver %s failed to get volume rootfs %s: %s", volumesDriver, c.ID, err)
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}
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return hostPath, nil
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}
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func (v *Volume) initialize(container *Container) error {
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var err error
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v.VolPath = filepath.Clean(v.VolPath)
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// Do not initialize an existing volume
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if _, exists := container.Volumes[v.VolPath]; exists {
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return nil
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}
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// If it's not a bindmount we need to create the dir on the host
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if !v.isBindMount {
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v.HostPath, err = createVolumeHostPath(container)
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if err != nil {
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return err
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}
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}
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for volPath := range binds {
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if err := initializeVolume(container, volPath, binds); err != nil {
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return err
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}
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hostPath, err := filepath.EvalSymlinks(v.HostPath)
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if err != nil {
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return err
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}
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// Create the mountpoint
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// This is the path to the volume within the container FS
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// This differs from `hostPath` in that `hostPath` refers to the place where
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// the volume data is actually stored on the host
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fullVolPath, err := symlink.FollowSymlinkInScope(filepath.Join(container.basefs, v.VolPath), container.basefs)
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if err != nil {
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return err
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}
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container.Volumes[v.VolPath] = hostPath
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container.VolumesRW[v.VolPath] = v.isRw()
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volIsDir, err := v.isDir()
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if err != nil {
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return err
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}
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if err := createIfNotExists(fullVolPath, volIsDir); err != nil {
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return err
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}
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// Do not copy or change permissions if we are mounting from the host
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if v.isRw() && !v.isBindMount {
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return copyExistingContents(fullVolPath, hostPath)
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}
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return nil
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}
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func createIfNotExists(destination string, isDir bool) error {
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if _, err := os.Stat(destination); err != nil && os.IsNotExist(err) {
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if isDir {
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if err := os.MkdirAll(destination, 0755); err != nil {
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return err
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}
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} else {
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if err := os.MkdirAll(filepath.Dir(destination), 0755); err != nil {
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return err
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}
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f, err := os.OpenFile(destination, os.O_CREATE, 0755)
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if err != nil {
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return err
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}
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f.Close()
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}
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}
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return nil
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}
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func initializeVolume(container *Container, volPath string, binds map[string]BindMap) error {
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volumesDriver := container.daemon.volumes.Driver()
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volPath = filepath.Clean(volPath)
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// Skip existing volumes
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if _, exists := container.Volumes[volPath]; exists {
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if _, err := os.Stat(destination); err == nil || !os.IsNotExist(err) {
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return nil
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}
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var (
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destination string
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isBindMount bool
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volIsDir = true
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srcRW = false
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)
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// If an external bind is defined for this volume, use that as a source
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if bindMap, exists := binds[volPath]; exists {
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isBindMount = true
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destination = bindMap.SrcPath
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if !filepath.IsAbs(destination) {
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return fmt.Errorf("cannot bind mount volume: %s volume paths must be absolute.", destination)
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}
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if strings.ToLower(bindMap.Mode) == "rw" {
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srcRW = true
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}
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if stat, err := os.Stat(bindMap.SrcPath); err != nil {
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return err
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} else {
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volIsDir = stat.IsDir()
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}
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} else {
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// Do not pass a container as the parameter for the volume creation.
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// The graph driver using the container's information ( Image ) to
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// create the parent.
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c, err := container.daemon.volumes.Create(nil, "", "", "", "", nil, nil)
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if err != nil {
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return err
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}
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destination, err = volumesDriver.Get(c.ID, "")
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if err != nil {
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return fmt.Errorf("Driver %s failed to get volume rootfs %s: %s", volumesDriver, c.ID, err)
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}
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srcRW = true
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if isDir {
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return os.MkdirAll(destination, 0755)
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}
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if p, err := filepath.EvalSymlinks(destination); err != nil {
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if err := os.MkdirAll(filepath.Dir(destination), 0755); err != nil {
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return err
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} else {
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destination = p
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}
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// Create the mountpoint
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source, err := symlink.FollowSymlinkInScope(filepath.Join(container.basefs, volPath), container.basefs)
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f, err := os.OpenFile(destination, os.O_CREATE, 0755)
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if err != nil {
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return err
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}
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f.Close()
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newVolPath, err := filepath.Rel(container.basefs, source)
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if err != nil {
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return err
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}
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newVolPath = "/" + newVolPath
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if volPath != newVolPath {
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delete(container.Volumes, volPath)
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delete(container.VolumesRW, volPath)
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}
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container.Volumes[volPath] = destination
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container.VolumesRW[volPath] = srcRW
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if err := createIfNotExists(source, volIsDir); err != nil {
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return err
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}
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// Do not copy or change permissions if we are mounting from the host
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if srcRW && !isBindMount {
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if err := copyExistingContents(source, destination); err != nil {
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return err
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}
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}
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return nil
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}
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