Skip to content

Commit

Permalink
Extract volume bind, creation and external methods.
Browse files Browse the repository at this point in the history 
Make Start() slightly more readable.
  • Loading branch information
@pnasrat
pnasrat committed Dec 3, 2013
1 parent 84f78d9 commit 40fe9f5
Showing 1 changed file with 165 additions and 148 deletions.
313 changes: 165 additions & 148 deletions container.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -541,160 +541,18 @@ func (container *Container) Start() (err error) {
log.Printf("WARNING: IPv4 forwarding is disabled. Networking will not work")
}

// Create the requested bind mounts
binds := make(map[string]BindMap)
// Define illegal container destinations
illegalDsts := []string{"/", "."}

for _, bind := range container.hostConfig.Binds {
// FIXME: factorize bind parsing in parseBind
var src, dst, mode string
arr := strings.Split(bind, ":")
if len(arr) == 2 {
src = arr[0]
dst = arr[1]
mode = "rw"
} else if len(arr) == 3 {
src = arr[0]
dst = arr[1]
mode = arr[2]
} else {
return fmt.Errorf("Invalid bind specification: %s", bind)
}

// Bail if trying to mount to an illegal destination
for _, illegal := range illegalDsts {
if dst == illegal {
return fmt.Errorf("Illegal bind destination: %s", dst)
}
}

bindMap := BindMap{
SrcPath: src,
DstPath: dst,
Mode: mode,
}
binds[path.Clean(dst)] = bindMap
}

if container.Volumes == nil || len(container.Volumes) == 0 {
container.Volumes = make(map[string]string)
container.VolumesRW = make(map[string]bool)
}

// Apply volumes from another container if requested
container.joinVolumes()

volumesDriver := container.runtime.volumes.driver
// Create the requested volumes if they don't exist
for volPath := range container.Config.Volumes {
volPath = path.Clean(volPath)
volIsDir := true
// Skip existing volumes
if _, exists := container.Volumes[volPath]; exists {
continue
}
var srcPath string
var isBindMount bool
srcRW := false
// If an external bind is defined for this volume, use that as a source
if bindMap, exists := binds[volPath]; exists {
isBindMount = true
srcPath = bindMap.SrcPath
if strings.ToLower(bindMap.Mode) == "rw" {
srcRW = true
}
if file, err := os.Open(bindMap.SrcPath); err != nil {
return err
} else {
defer file.Close()
if stat, err := file.Stat(); err != nil {
return err
} else {
volIsDir = stat.IsDir()
}
}
// Otherwise create an directory in $ROOT/volumes/ and use that
} else {

// Do not pass a container as the parameter for the volume creation.
// The graph driver using the container's information ( Image ) to
// create the parent.
c, err := container.runtime.volumes.Create(nil, nil, "", "", nil)
if err != nil {
return err
}
srcPath, err = volumesDriver.Get(c.ID)
if err != nil {
return fmt.Errorf("Driver %s failed to get volume rootfs %s: %s", volumesDriver, c.ID, err)
}
srcRW = true // RW by default
}
container.Volumes[volPath] = srcPath
container.VolumesRW[volPath] = srcRW
// Create the mountpoint
rootVolPath := path.Join(container.RootfsPath(), volPath)
if volIsDir {
if err := os.MkdirAll(rootVolPath, 0755); err != nil {
return err
}
}

volPath = path.Join(container.RootfsPath(), volPath)
if _, err := os.Stat(volPath); err != nil {
if os.IsNotExist(err) {
if volIsDir {
if err := os.MkdirAll(volPath, 0755); err != nil {
return err
}
} else {
if err := os.MkdirAll(path.Dir(volPath), 0755); err != nil {
return err
}
if f, err := os.OpenFile(volPath, os.O_CREATE, 0755); err != nil {
return err
} else {
f.Close()
}
}
}
}

// Do not copy or change permissions if we are mounting from the host
if srcRW && !isBindMount {
volList, err := ioutil.ReadDir(rootVolPath)
if err != nil {
return err
}
if len(volList) > 0 {
srcList, err := ioutil.ReadDir(srcPath)
if err != nil {
return err
}
if len(srcList) == 0 {
// If the source volume is empty copy files from the root into the volume
if err := archive.CopyWithTar(rootVolPath, srcPath); err != nil {
return err
}
if err := container.applyExternalVolumes(); err != nil {
return err
}

var stat syscall.Stat_t
if err := syscall.Stat(rootVolPath, &stat); err != nil {
return err
}
var srcStat syscall.Stat_t
if err := syscall.Stat(srcPath, &srcStat); err != nil {
return err
}
// Change the source volume's ownership if it differs from the root
// files that where just copied
if stat.Uid != srcStat.Uid || stat.Gid != srcStat.Gid {
if err := os.Chown(srcPath, int(stat.Uid), int(stat.Gid)); err != nil {
return err
}
}
}
}
}
if err := container.createVolumes(); err != nil {
return err
}

if err := container.generateLXCConfig(); err != nil {
Expand Down Expand Up @@ -880,7 +738,165 @@ func (container *Container) Start() (err error) {
return ErrContainerStart
}

func (container *Container) joinVolumes() error {
func (container *Container) getBindMap() (map[string]BindMap, error) {
// Create the requested bind mounts
binds := make(map[string]BindMap)
// Define illegal container destinations
illegalDsts := []string{"/", "."}

for _, bind := range container.hostConfig.Binds {
// FIXME: factorize bind parsing in parseBind
var src, dst, mode string
arr := strings.Split(bind, ":")
if len(arr) == 2 {
src = arr[0]
dst = arr[1]
mode = "rw"
} else if len(arr) == 3 {
src = arr[0]
dst = arr[1]
mode = arr[2]
} else {
return nil, fmt.Errorf("Invalid bind specification: %s", bind)
}

// Bail if trying to mount to an illegal destination
for _, illegal := range illegalDsts {
if dst == illegal {
return nil, fmt.Errorf("Illegal bind destination: %s", dst)
}
}

bindMap := BindMap{
SrcPath: src,
DstPath: dst,
Mode: mode,
}
binds[path.Clean(dst)] = bindMap
}
return binds, nil
}

func (container *Container) createVolumes() error {
binds, err := container.getBindMap()
if err != nil {
return err
}
volumesDriver := container.runtime.volumes.driver
// Create the requested volumes if they don't exist
for volPath := range container.Config.Volumes {
volPath = path.Clean(volPath)
volIsDir := true
// Skip existing volumes
if _, exists := container.Volumes[volPath]; exists {
continue
}
var srcPath string
var isBindMount bool
srcRW := false
// If an external bind is defined for this volume, use that as a source
if bindMap, exists := binds[volPath]; exists {
isBindMount = true
srcPath = bindMap.SrcPath
if strings.ToLower(bindMap.Mode) == "rw" {
srcRW = true
}
if file, err := os.Open(bindMap.SrcPath); err != nil {
return err
} else {
defer file.Close()
if stat, err := file.Stat(); err != nil {
return err
} else {
volIsDir = stat.IsDir()
}
}
// Otherwise create an directory in $ROOT/volumes/ and use that
} else {

// Do not pass a container as the parameter for the volume creation.
// The graph driver using the container's information ( Image ) to
// create the parent.
c, err := container.runtime.volumes.Create(nil, nil, "", "", nil)
if err != nil {
return err
}
srcPath, err = volumesDriver.Get(c.ID)
if err != nil {
return fmt.Errorf("Driver %s failed to get volume rootfs %s: %s", volumesDriver, c.ID, err)
}
srcRW = true // RW by default
}
container.Volumes[volPath] = srcPath
container.VolumesRW[volPath] = srcRW
// Create the mountpoint
rootVolPath := path.Join(container.RootfsPath(), volPath)
if volIsDir {
if err := os.MkdirAll(rootVolPath, 0755); err != nil {
return err
}
}

volPath = path.Join(container.RootfsPath(), volPath)
if _, err := os.Stat(volPath); err != nil {
if os.IsNotExist(err) {
if volIsDir {
if err := os.MkdirAll(volPath, 0755); err != nil {
return err
}
} else {
if err := os.MkdirAll(path.Dir(volPath), 0755); err != nil {
return err
}
if f, err := os.OpenFile(volPath, os.O_CREATE, 0755); err != nil {
return err
} else {
f.Close()
}
}
}
}

// Do not copy or change permissions if we are mounting from the host
if srcRW && !isBindMount {
volList, err := ioutil.ReadDir(rootVolPath)
if err != nil {
return err
}
if len(volList) > 0 {
srcList, err := ioutil.ReadDir(srcPath)
if err != nil {
return err
}
if len(srcList) == 0 {
// If the source volume is empty copy files from the root into the volume
if err := archive.CopyWithTar(rootVolPath, srcPath); err != nil {
return err
}

var stat syscall.Stat_t
if err := syscall.Stat(rootVolPath, &stat); err != nil {
return err
}
var srcStat syscall.Stat_t
if err := syscall.Stat(srcPath, &srcStat); err != nil {
return err
}
// Change the source volume's ownership if it differs from the root
// files that where just copied
if stat.Uid != srcStat.Uid || stat.Gid != srcStat.Gid {
if err := os.Chown(srcPath, int(stat.Uid), int(stat.Gid)); err != nil {
return err
}
}
}
}
}
}
return nil
}

func (container *Container) applyExternalVolumes() error {
if container.Config.VolumesFrom != "" {
containerSpecs := strings.Split(container.Config.VolumesFrom, ",")
for _, containerSpec := range containerSpecs {
Expand Down Expand Up @@ -917,6 +933,7 @@ func (container *Container) joinVolumes() error {

}
}
return nil
}

func (container *Container) Run() error {
Expand Down

0 comments on commit 40fe9f5

Please sign in to comment.