374 lines
10 KiB
Go
374 lines
10 KiB
Go
package allocdir
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"os"
|
|
"path/filepath"
|
|
"time"
|
|
|
|
"github.com/hashicorp/go-multierror"
|
|
"github.com/hashicorp/nomad/nomad/structs"
|
|
)
|
|
|
|
var (
|
|
// The name of the directory that is shared across tasks in a task group.
|
|
SharedAllocName = "alloc"
|
|
|
|
// Name of the directory where logs of Tasks are written
|
|
LogDirName = "logs"
|
|
|
|
// The set of directories that exist inside eache shared alloc directory.
|
|
SharedAllocDirs = []string{LogDirName, "tmp", "data"}
|
|
|
|
// The name of the directory that exists inside each task directory
|
|
// regardless of driver.
|
|
TaskLocal = "local"
|
|
|
|
// TaskDirs is the set of directories created in each tasks directory.
|
|
TaskDirs = []string{"tmp"}
|
|
)
|
|
|
|
type AllocDir struct {
|
|
// AllocDir is the directory used for storing any state
|
|
// of this allocation. It will be purged on alloc destroy.
|
|
AllocDir string
|
|
|
|
// The shared directory is available to all tasks within the same task
|
|
// group.
|
|
SharedDir string
|
|
|
|
// TaskDirs is a mapping of task names to their non-shared directory.
|
|
TaskDirs map[string]string
|
|
}
|
|
|
|
// AllocFileInfo holds information about a file inside the AllocDir
|
|
type AllocFileInfo struct {
|
|
Name string
|
|
IsDir bool
|
|
Size int64
|
|
FileMode string
|
|
ModTime time.Time
|
|
}
|
|
|
|
// AllocDirFS exposes file operations on the alloc dir
|
|
type AllocDirFS interface {
|
|
List(path string) ([]*AllocFileInfo, error)
|
|
Stat(path string) (*AllocFileInfo, error)
|
|
ReadAt(path string, offset int64, limit int64) (io.ReadCloser, error)
|
|
}
|
|
|
|
func NewAllocDir(allocDir string) *AllocDir {
|
|
d := &AllocDir{AllocDir: allocDir, TaskDirs: make(map[string]string)}
|
|
d.SharedDir = filepath.Join(d.AllocDir, SharedAllocName)
|
|
return d
|
|
}
|
|
|
|
// Tears down previously build directory structure.
|
|
func (d *AllocDir) Destroy() error {
|
|
// Unmount all mounted shared alloc dirs.
|
|
var mErr multierror.Error
|
|
if err := d.UnmountAll(); err != nil {
|
|
mErr.Errors = append(mErr.Errors, err)
|
|
}
|
|
|
|
if err := os.RemoveAll(d.AllocDir); err != nil {
|
|
mErr.Errors = append(mErr.Errors, err)
|
|
}
|
|
|
|
return mErr.ErrorOrNil()
|
|
}
|
|
|
|
func (d *AllocDir) UnmountAll() error {
|
|
var mErr multierror.Error
|
|
for _, dir := range d.TaskDirs {
|
|
// Check if the directory has the shared alloc mounted.
|
|
taskAlloc := filepath.Join(dir, SharedAllocName)
|
|
if d.pathExists(taskAlloc) {
|
|
if err := d.unmountSharedDir(taskAlloc); err != nil {
|
|
mErr.Errors = append(mErr.Errors,
|
|
fmt.Errorf("failed to unmount shared alloc dir %q: %v", taskAlloc, err))
|
|
} else if err := os.RemoveAll(taskAlloc); err != nil {
|
|
mErr.Errors = append(mErr.Errors,
|
|
fmt.Errorf("failed to delete shared alloc dir %q: %v", taskAlloc, err))
|
|
}
|
|
}
|
|
|
|
// Unmount dev/ and proc/ have been mounted.
|
|
d.unmountSpecialDirs(dir)
|
|
}
|
|
|
|
return mErr.ErrorOrNil()
|
|
}
|
|
|
|
// Given a list of a task build the correct alloc structure.
|
|
func (d *AllocDir) Build(tasks []*structs.Task) error {
|
|
// Make the alloc directory, owned by the nomad process.
|
|
if err := os.MkdirAll(d.AllocDir, 0755); err != nil {
|
|
return fmt.Errorf("Failed to make the alloc directory %v: %v", d.AllocDir, err)
|
|
}
|
|
|
|
// Make the shared directory and make it available to all user/groups.
|
|
if err := os.MkdirAll(d.SharedDir, 0777); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Make the shared directory have non-root permissions.
|
|
if err := d.dropDirPermissions(d.SharedDir); err != nil {
|
|
return err
|
|
}
|
|
|
|
for _, dir := range SharedAllocDirs {
|
|
p := filepath.Join(d.SharedDir, dir)
|
|
if err := os.MkdirAll(p, 0777); err != nil {
|
|
return err
|
|
}
|
|
if err := d.dropDirPermissions(p); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// Make the task directories.
|
|
for _, t := range tasks {
|
|
taskDir := filepath.Join(d.AllocDir, t.Name)
|
|
if err := os.MkdirAll(taskDir, 0777); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Make the task directory have non-root permissions.
|
|
if err := d.dropDirPermissions(taskDir); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Create a local directory that each task can use.
|
|
local := filepath.Join(taskDir, TaskLocal)
|
|
if err := os.MkdirAll(local, 0777); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := d.dropDirPermissions(local); err != nil {
|
|
return err
|
|
}
|
|
|
|
d.TaskDirs[t.Name] = taskDir
|
|
|
|
// Create the directories that should be in every task.
|
|
for _, dir := range TaskDirs {
|
|
local := filepath.Join(taskDir, dir)
|
|
if err := os.MkdirAll(local, 0777); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := d.dropDirPermissions(local); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Embed takes a mapping of absolute directory or file paths on the host to
|
|
// their intended, relative location within the task directory. Embed attempts
|
|
// hardlink and then defaults to copying. If the path exists on the host and
|
|
// can't be embedded an error is returned.
|
|
func (d *AllocDir) Embed(task string, entries map[string]string) error {
|
|
taskdir, ok := d.TaskDirs[task]
|
|
if !ok {
|
|
return fmt.Errorf("Task directory doesn't exist for task %v", task)
|
|
}
|
|
|
|
subdirs := make(map[string]string)
|
|
for source, dest := range entries {
|
|
// Check to see if directory exists on host.
|
|
s, err := os.Stat(source)
|
|
if os.IsNotExist(err) {
|
|
continue
|
|
}
|
|
|
|
// Embedding a single file
|
|
if !s.IsDir() {
|
|
destDir := filepath.Join(taskdir, filepath.Dir(dest))
|
|
if err := os.MkdirAll(destDir, s.Mode().Perm()); err != nil {
|
|
return fmt.Errorf("Couldn't create destination directory %v: %v", destDir, err)
|
|
}
|
|
|
|
// Copy the file.
|
|
taskEntry := filepath.Join(destDir, filepath.Base(dest))
|
|
if err := d.linkOrCopy(source, taskEntry, s.Mode().Perm()); err != nil {
|
|
return err
|
|
}
|
|
|
|
continue
|
|
}
|
|
|
|
// Create destination directory.
|
|
destDir := filepath.Join(taskdir, dest)
|
|
if err := os.MkdirAll(destDir, s.Mode().Perm()); err != nil {
|
|
return fmt.Errorf("Couldn't create destination directory %v: %v", destDir, err)
|
|
}
|
|
|
|
// Enumerate the files in source.
|
|
dirEntries, err := ioutil.ReadDir(source)
|
|
if err != nil {
|
|
return fmt.Errorf("Couldn't read directory %v: %v", source, err)
|
|
}
|
|
|
|
for _, entry := range dirEntries {
|
|
hostEntry := filepath.Join(source, entry.Name())
|
|
taskEntry := filepath.Join(destDir, filepath.Base(hostEntry))
|
|
if entry.IsDir() {
|
|
subdirs[hostEntry] = filepath.Join(dest, filepath.Base(hostEntry))
|
|
continue
|
|
}
|
|
|
|
// Check if entry exists. This can happen if restarting a failed
|
|
// task.
|
|
if _, err := os.Lstat(taskEntry); err == nil {
|
|
continue
|
|
}
|
|
|
|
if !entry.Mode().IsRegular() {
|
|
// If it is a symlink we can create it, otherwise we skip it.
|
|
if entry.Mode()&os.ModeSymlink == 0 {
|
|
continue
|
|
}
|
|
|
|
link, err := os.Readlink(hostEntry)
|
|
if err != nil {
|
|
return fmt.Errorf("Couldn't resolve symlink for %v: %v", source, err)
|
|
}
|
|
|
|
if err := os.Symlink(link, taskEntry); err != nil {
|
|
// Symlinking twice
|
|
if err.(*os.LinkError).Err.Error() != "file exists" {
|
|
return fmt.Errorf("Couldn't create symlink: %v", err)
|
|
}
|
|
}
|
|
continue
|
|
}
|
|
|
|
if err := d.linkOrCopy(hostEntry, taskEntry, entry.Mode().Perm()); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
|
|
// Recurse on self to copy subdirectories.
|
|
if len(subdirs) != 0 {
|
|
return d.Embed(task, subdirs)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// MountSharedDir mounts the shared directory into the specified task's
|
|
// directory. Mount is documented at an OS level in their respective
|
|
// implementation files.
|
|
func (d *AllocDir) MountSharedDir(task string) error {
|
|
taskDir, ok := d.TaskDirs[task]
|
|
if !ok {
|
|
return fmt.Errorf("No task directory exists for %v", task)
|
|
}
|
|
|
|
taskLoc := filepath.Join(taskDir, SharedAllocName)
|
|
if err := d.mountSharedDir(taskLoc); err != nil {
|
|
return fmt.Errorf("Failed to mount shared directory for task %v: %v", task, err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// LogDir returns the log dir in the current allocation directory
|
|
func (d *AllocDir) LogDir() string {
|
|
return filepath.Join(d.AllocDir, SharedAllocName, LogDirName)
|
|
}
|
|
|
|
// List returns the list of files at a path relative to the alloc dir
|
|
func (d *AllocDir) List(path string) ([]*AllocFileInfo, error) {
|
|
p := filepath.Join(d.AllocDir, path)
|
|
finfos, err := ioutil.ReadDir(p)
|
|
if err != nil {
|
|
return []*AllocFileInfo{}, err
|
|
}
|
|
files := make([]*AllocFileInfo, len(finfos))
|
|
for idx, info := range finfos {
|
|
files[idx] = &AllocFileInfo{
|
|
Name: info.Name(),
|
|
IsDir: info.IsDir(),
|
|
Size: info.Size(),
|
|
FileMode: info.Mode().String(),
|
|
ModTime: info.ModTime(),
|
|
}
|
|
}
|
|
return files, err
|
|
}
|
|
|
|
// Stat returns information about the file at a path relative to the alloc dir
|
|
func (d *AllocDir) Stat(path string) (*AllocFileInfo, error) {
|
|
p := filepath.Join(d.AllocDir, path)
|
|
info, err := os.Stat(p)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &AllocFileInfo{
|
|
Size: info.Size(),
|
|
Name: info.Name(),
|
|
IsDir: info.IsDir(),
|
|
FileMode: info.Mode().String(),
|
|
ModTime: info.ModTime(),
|
|
}, nil
|
|
}
|
|
|
|
// ReadAt returns a reader for a file at the path relative to the alloc dir
|
|
// which will read a chunk of bytes at a particular offset
|
|
func (d *AllocDir) ReadAt(path string, offset int64, limit int64) (io.ReadCloser, error) {
|
|
p := filepath.Join(d.AllocDir, path)
|
|
f, err := os.Open(p)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if _, err := f.Seek(offset, 0); err != nil {
|
|
return nil, fmt.Errorf("can't seek to offset %q: %v", offset, err)
|
|
}
|
|
return &ReadCloserWrapper{Reader: io.LimitReader(f, limit), Closer: f}, nil
|
|
}
|
|
|
|
// ReadCloserWrapper wraps a LimitReader so that a file is closed once it has been
|
|
// read
|
|
type ReadCloserWrapper struct {
|
|
io.Reader
|
|
io.Closer
|
|
}
|
|
|
|
func fileCopy(src, dst string, perm os.FileMode) error {
|
|
// Do a simple copy.
|
|
srcFile, err := os.Open(src)
|
|
if err != nil {
|
|
return fmt.Errorf("Couldn't open src file %v: %v", src, err)
|
|
}
|
|
|
|
dstFile, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE, perm)
|
|
if err != nil {
|
|
return fmt.Errorf("Couldn't create destination file %v: %v", dst, err)
|
|
}
|
|
|
|
if _, err := io.Copy(dstFile, srcFile); err != nil {
|
|
return fmt.Errorf("Couldn't copy %v to %v: %v", src, dst, err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// pathExists is a helper function to check if the path exists.
|
|
func (d *AllocDir) pathExists(path string) bool {
|
|
if _, err := os.Stat(path); err != nil {
|
|
if os.IsNotExist(err) {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|