2015-07-21 13:50:10 -04:00
|
|
|
// Package local provides the default implementation for volumes. It
|
|
|
|
// is used to mount data volume containers and directories local to
|
|
|
|
// the host server.
|
2015-05-19 16:05:25 -04:00
|
|
|
package local
|
|
|
|
|
|
|
|
import (
|
2016-02-11 21:48:16 -05:00
|
|
|
"encoding/json"
|
2015-05-19 16:05:25 -04:00
|
|
|
"fmt"
|
|
|
|
"io/ioutil"
|
|
|
|
"os"
|
|
|
|
"path/filepath"
|
|
|
|
"sync"
|
|
|
|
|
2016-02-11 21:48:16 -05:00
|
|
|
"github.com/Sirupsen/logrus"
|
2015-10-08 11:51:41 -04:00
|
|
|
"github.com/docker/docker/pkg/idtools"
|
2016-02-11 21:48:16 -05:00
|
|
|
"github.com/docker/docker/pkg/mount"
|
2015-10-20 13:09:48 -04:00
|
|
|
"github.com/docker/docker/utils"
|
2015-05-19 16:05:25 -04:00
|
|
|
"github.com/docker/docker/volume"
|
|
|
|
)
|
|
|
|
|
2015-06-03 12:26:41 -04:00
|
|
|
// VolumeDataPathName is the name of the directory where the volume data is stored.
|
2015-12-13 11:00:39 -05:00
|
|
|
// It uses a very distinctive name to avoid collisions migrating data between
|
2015-06-03 12:26:41 -04:00
|
|
|
// Docker versions.
|
|
|
|
const (
|
|
|
|
VolumeDataPathName = "_data"
|
|
|
|
volumesPathName = "volumes"
|
|
|
|
)
|
|
|
|
|
2015-10-20 13:09:48 -04:00
|
|
|
var (
|
|
|
|
// ErrNotFound is the typed error returned when the requested volume name can't be found
|
Remove static errors from errors package.
Moving all strings to the errors package wasn't a good idea after all.
Our custom implementation of Go errors predates everything that's nice
and good about working with errors in Go. Take as an example what we
have to do to get an error message:
```go
func GetErrorMessage(err error) string {
switch err.(type) {
case errcode.Error:
e, _ := err.(errcode.Error)
return e.Message
case errcode.ErrorCode:
ec, _ := err.(errcode.ErrorCode)
return ec.Message()
default:
return err.Error()
}
}
```
This goes against every good practice for Go development. The language already provides a simple, intuitive and standard way to get error messages, that is calling the `Error()` method from an error. Reinventing the error interface is a mistake.
Our custom implementation also makes very hard to reason about errors, another nice thing about Go. I found several (>10) error declarations that we don't use anywhere. This is a clear sign about how little we know about the errors we return. I also found several error usages where the number of arguments was different than the parameters declared in the error, another clear example of how difficult is to reason about errors.
Moreover, our custom implementation didn't really make easier for people to return custom HTTP status code depending on the errors. Again, it's hard to reason about when to set custom codes and how. Take an example what we have to do to extract the message and status code from an error before returning a response from the API:
```go
switch err.(type) {
case errcode.ErrorCode:
daError, _ := err.(errcode.ErrorCode)
statusCode = daError.Descriptor().HTTPStatusCode
errMsg = daError.Message()
case errcode.Error:
// For reference, if you're looking for a particular error
// then you can do something like :
// import ( derr "github.com/docker/docker/errors" )
// if daError.ErrorCode() == derr.ErrorCodeNoSuchContainer { ... }
daError, _ := err.(errcode.Error)
statusCode = daError.ErrorCode().Descriptor().HTTPStatusCode
errMsg = daError.Message
default:
// This part of will be removed once we've
// converted everything over to use the errcode package
// FIXME: this is brittle and should not be necessary.
// If we need to differentiate between different possible error types,
// we should create appropriate error types with clearly defined meaning
errStr := strings.ToLower(err.Error())
for keyword, status := range map[string]int{
"not found": http.StatusNotFound,
"no such": http.StatusNotFound,
"bad parameter": http.StatusBadRequest,
"conflict": http.StatusConflict,
"impossible": http.StatusNotAcceptable,
"wrong login/password": http.StatusUnauthorized,
"hasn't been activated": http.StatusForbidden,
} {
if strings.Contains(errStr, keyword) {
statusCode = status
break
}
}
}
```
You can notice two things in that code:
1. We have to explain how errors work, because our implementation goes against how easy to use Go errors are.
2. At no moment we arrived to remove that `switch` statement that was the original reason to use our custom implementation.
This change removes all our status errors from the errors package and puts them back in their specific contexts.
IT puts the messages back with their contexts. That way, we know right away when errors used and how to generate their messages.
It uses custom interfaces to reason about errors. Errors that need to response with a custom status code MUST implementent this simple interface:
```go
type errorWithStatus interface {
HTTPErrorStatusCode() int
}
```
This interface is very straightforward to implement. It also preserves Go errors real behavior, getting the message is as simple as using the `Error()` method.
I included helper functions to generate errors that use custom status code in `errors/errors.go`.
By doing this, we remove the hard dependency we have eeverywhere to our custom errors package. Yes, you can use it as a helper to generate error, but it's still very easy to generate errors without it.
Please, read this fantastic blog post about errors in Go: http://dave.cheney.net/2014/12/24/inspecting-errors
Signed-off-by: David Calavera <david.calavera@gmail.com>
2016-02-25 10:53:35 -05:00
|
|
|
ErrNotFound = fmt.Errorf("volume not found")
|
2015-12-13 11:00:39 -05:00
|
|
|
// volumeNameRegex ensures the name assigned for the volume is valid.
|
2015-10-20 13:09:48 -04:00
|
|
|
// This name is used to create the bind directory, so we need to avoid characters that
|
|
|
|
// would make the path to escape the root directory.
|
2016-01-04 18:00:49 -05:00
|
|
|
volumeNameRegex = utils.RestrictedVolumeNamePattern
|
2015-10-20 13:09:48 -04:00
|
|
|
)
|
2015-06-03 12:26:41 -04:00
|
|
|
|
Remove static errors from errors package.
Moving all strings to the errors package wasn't a good idea after all.
Our custom implementation of Go errors predates everything that's nice
and good about working with errors in Go. Take as an example what we
have to do to get an error message:
```go
func GetErrorMessage(err error) string {
switch err.(type) {
case errcode.Error:
e, _ := err.(errcode.Error)
return e.Message
case errcode.ErrorCode:
ec, _ := err.(errcode.ErrorCode)
return ec.Message()
default:
return err.Error()
}
}
```
This goes against every good practice for Go development. The language already provides a simple, intuitive and standard way to get error messages, that is calling the `Error()` method from an error. Reinventing the error interface is a mistake.
Our custom implementation also makes very hard to reason about errors, another nice thing about Go. I found several (>10) error declarations that we don't use anywhere. This is a clear sign about how little we know about the errors we return. I also found several error usages where the number of arguments was different than the parameters declared in the error, another clear example of how difficult is to reason about errors.
Moreover, our custom implementation didn't really make easier for people to return custom HTTP status code depending on the errors. Again, it's hard to reason about when to set custom codes and how. Take an example what we have to do to extract the message and status code from an error before returning a response from the API:
```go
switch err.(type) {
case errcode.ErrorCode:
daError, _ := err.(errcode.ErrorCode)
statusCode = daError.Descriptor().HTTPStatusCode
errMsg = daError.Message()
case errcode.Error:
// For reference, if you're looking for a particular error
// then you can do something like :
// import ( derr "github.com/docker/docker/errors" )
// if daError.ErrorCode() == derr.ErrorCodeNoSuchContainer { ... }
daError, _ := err.(errcode.Error)
statusCode = daError.ErrorCode().Descriptor().HTTPStatusCode
errMsg = daError.Message
default:
// This part of will be removed once we've
// converted everything over to use the errcode package
// FIXME: this is brittle and should not be necessary.
// If we need to differentiate between different possible error types,
// we should create appropriate error types with clearly defined meaning
errStr := strings.ToLower(err.Error())
for keyword, status := range map[string]int{
"not found": http.StatusNotFound,
"no such": http.StatusNotFound,
"bad parameter": http.StatusBadRequest,
"conflict": http.StatusConflict,
"impossible": http.StatusNotAcceptable,
"wrong login/password": http.StatusUnauthorized,
"hasn't been activated": http.StatusForbidden,
} {
if strings.Contains(errStr, keyword) {
statusCode = status
break
}
}
}
```
You can notice two things in that code:
1. We have to explain how errors work, because our implementation goes against how easy to use Go errors are.
2. At no moment we arrived to remove that `switch` statement that was the original reason to use our custom implementation.
This change removes all our status errors from the errors package and puts them back in their specific contexts.
IT puts the messages back with their contexts. That way, we know right away when errors used and how to generate their messages.
It uses custom interfaces to reason about errors. Errors that need to response with a custom status code MUST implementent this simple interface:
```go
type errorWithStatus interface {
HTTPErrorStatusCode() int
}
```
This interface is very straightforward to implement. It also preserves Go errors real behavior, getting the message is as simple as using the `Error()` method.
I included helper functions to generate errors that use custom status code in `errors/errors.go`.
By doing this, we remove the hard dependency we have eeverywhere to our custom errors package. Yes, you can use it as a helper to generate error, but it's still very easy to generate errors without it.
Please, read this fantastic blog post about errors in Go: http://dave.cheney.net/2014/12/24/inspecting-errors
Signed-off-by: David Calavera <david.calavera@gmail.com>
2016-02-25 10:53:35 -05:00
|
|
|
type validationError struct {
|
|
|
|
error
|
|
|
|
}
|
|
|
|
|
|
|
|
func (validationError) IsValidationError() bool {
|
|
|
|
return true
|
|
|
|
}
|
|
|
|
|
2016-02-11 21:48:16 -05:00
|
|
|
type activeMount struct {
|
|
|
|
count uint64
|
|
|
|
mounted bool
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// New instantiates a new Root instance with the provided scope. Scope
|
|
|
|
// is the base path that the Root instance uses to store its
|
|
|
|
// volumes. The base path is created here if it does not exist.
|
2015-10-08 11:51:41 -04:00
|
|
|
func New(scope string, rootUID, rootGID int) (*Root, error) {
|
2015-06-03 12:26:41 -04:00
|
|
|
rootDirectory := filepath.Join(scope, volumesPathName)
|
|
|
|
|
2015-10-08 11:51:41 -04:00
|
|
|
if err := idtools.MkdirAllAs(rootDirectory, 0700, rootUID, rootGID); err != nil {
|
2015-05-19 16:05:25 -04:00
|
|
|
return nil, err
|
|
|
|
}
|
2015-06-03 12:26:41 -04:00
|
|
|
|
2015-05-19 16:05:25 -04:00
|
|
|
r := &Root{
|
2015-06-03 12:26:41 -04:00
|
|
|
scope: scope,
|
2015-05-19 16:05:25 -04:00
|
|
|
path: rootDirectory,
|
2015-07-21 13:50:10 -04:00
|
|
|
volumes: make(map[string]*localVolume),
|
2015-10-08 11:51:41 -04:00
|
|
|
rootUID: rootUID,
|
|
|
|
rootGID: rootGID,
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
2015-06-03 12:26:41 -04:00
|
|
|
|
2015-05-19 16:05:25 -04:00
|
|
|
dirs, err := ioutil.ReadDir(rootDirectory)
|
|
|
|
if err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
2015-06-03 12:26:41 -04:00
|
|
|
|
2016-02-11 21:48:16 -05:00
|
|
|
mountInfos, err := mount.GetMounts()
|
|
|
|
if err != nil {
|
|
|
|
logrus.Debugf("error looking up mounts for local volume cleanup: %v", err)
|
|
|
|
}
|
|
|
|
|
2015-05-19 16:05:25 -04:00
|
|
|
for _, d := range dirs {
|
2016-03-16 17:52:34 -04:00
|
|
|
if !d.IsDir() {
|
|
|
|
continue
|
|
|
|
}
|
|
|
|
|
2015-05-19 16:05:25 -04:00
|
|
|
name := filepath.Base(d.Name())
|
2016-02-11 21:48:16 -05:00
|
|
|
v := &localVolume{
|
2015-05-19 16:05:25 -04:00
|
|
|
driverName: r.Name(),
|
|
|
|
name: name,
|
2015-06-03 12:26:41 -04:00
|
|
|
path: r.DataPath(name),
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
2016-02-11 21:48:16 -05:00
|
|
|
r.volumes[name] = v
|
|
|
|
if b, err := ioutil.ReadFile(filepath.Join(name, "opts.json")); err == nil {
|
|
|
|
if err := json.Unmarshal(b, v.opts); err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
|
|
|
|
// unmount anything that may still be mounted (for example, from an unclean shutdown)
|
|
|
|
for _, info := range mountInfos {
|
|
|
|
if info.Mountpoint == v.path {
|
|
|
|
mount.Unmount(v.path)
|
|
|
|
break
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
2015-06-12 09:25:32 -04:00
|
|
|
|
2015-05-19 16:05:25 -04:00
|
|
|
return r, nil
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Root implements the Driver interface for the volume package and
|
|
|
|
// manages the creation/removal of volumes. It uses only standard vfs
|
|
|
|
// commands to create/remove dirs within its provided scope.
|
2015-05-19 16:05:25 -04:00
|
|
|
type Root struct {
|
|
|
|
m sync.Mutex
|
2015-06-03 12:26:41 -04:00
|
|
|
scope string
|
2015-05-19 16:05:25 -04:00
|
|
|
path string
|
2015-07-21 13:50:10 -04:00
|
|
|
volumes map[string]*localVolume
|
2015-10-08 11:51:41 -04:00
|
|
|
rootUID int
|
|
|
|
rootGID int
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
|
|
|
|
2015-06-12 09:25:32 -04:00
|
|
|
// List lists all the volumes
|
2015-09-23 16:29:14 -04:00
|
|
|
func (r *Root) List() ([]volume.Volume, error) {
|
2015-06-12 09:25:32 -04:00
|
|
|
var ls []volume.Volume
|
2016-03-22 14:21:38 -04:00
|
|
|
r.m.Lock()
|
2015-06-12 09:25:32 -04:00
|
|
|
for _, v := range r.volumes {
|
|
|
|
ls = append(ls, v)
|
|
|
|
}
|
2016-03-22 14:21:38 -04:00
|
|
|
r.m.Unlock()
|
2015-09-23 16:29:14 -04:00
|
|
|
return ls, nil
|
2015-06-12 09:25:32 -04:00
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// DataPath returns the constructed path of this volume.
|
2015-06-03 12:26:41 -04:00
|
|
|
func (r *Root) DataPath(volumeName string) string {
|
|
|
|
return filepath.Join(r.path, volumeName, VolumeDataPathName)
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Name returns the name of Root, defined in the volume package in the DefaultDriverName constant.
|
2015-05-19 16:05:25 -04:00
|
|
|
func (r *Root) Name() string {
|
2015-07-21 13:50:10 -04:00
|
|
|
return volume.DefaultDriverName
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Create creates a new volume.Volume with the provided name, creating
|
|
|
|
// the underlying directory tree required for this volume in the
|
|
|
|
// process.
|
2016-02-11 21:48:16 -05:00
|
|
|
func (r *Root) Create(name string, opts map[string]string) (volume.Volume, error) {
|
2015-10-20 13:09:48 -04:00
|
|
|
if err := r.validateName(name); err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
|
2015-05-19 16:05:25 -04:00
|
|
|
r.m.Lock()
|
|
|
|
defer r.m.Unlock()
|
2015-06-03 12:26:41 -04:00
|
|
|
|
2015-05-19 16:05:25 -04:00
|
|
|
v, exists := r.volumes[name]
|
2015-06-12 09:25:32 -04:00
|
|
|
if exists {
|
|
|
|
return v, nil
|
|
|
|
}
|
|
|
|
|
|
|
|
path := r.DataPath(name)
|
2015-10-08 11:51:41 -04:00
|
|
|
if err := idtools.MkdirAllAs(path, 0755, r.rootUID, r.rootGID); err != nil {
|
2015-06-12 09:25:32 -04:00
|
|
|
if os.IsExist(err) {
|
|
|
|
return nil, fmt.Errorf("volume already exists under %s", filepath.Dir(path))
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
2015-06-12 09:25:32 -04:00
|
|
|
return nil, err
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
2016-02-11 21:48:16 -05:00
|
|
|
|
|
|
|
var err error
|
|
|
|
defer func() {
|
|
|
|
if err != nil {
|
|
|
|
os.RemoveAll(filepath.Dir(path))
|
|
|
|
}
|
|
|
|
}()
|
|
|
|
|
2015-06-12 09:25:32 -04:00
|
|
|
v = &localVolume{
|
|
|
|
driverName: r.Name(),
|
|
|
|
name: name,
|
|
|
|
path: path,
|
|
|
|
}
|
2016-02-11 21:48:16 -05:00
|
|
|
|
|
|
|
if opts != nil {
|
|
|
|
if err = setOpts(v, opts); err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
var b []byte
|
|
|
|
b, err = json.Marshal(v.opts)
|
|
|
|
if err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
if err = ioutil.WriteFile(filepath.Join(filepath.Dir(path), "opts.json"), b, 600); err != nil {
|
|
|
|
return nil, err
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-06-12 09:25:32 -04:00
|
|
|
r.volumes[name] = v
|
2015-05-19 16:05:25 -04:00
|
|
|
return v, nil
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Remove removes the specified volume and all underlying data. If the
|
|
|
|
// given volume does not belong to this driver and an error is
|
|
|
|
// returned. The volume is reference counted, if all references are
|
|
|
|
// not released then the volume is not removed.
|
2015-05-19 16:05:25 -04:00
|
|
|
func (r *Root) Remove(v volume.Volume) error {
|
|
|
|
r.m.Lock()
|
|
|
|
defer r.m.Unlock()
|
2015-09-08 22:01:02 -04:00
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
lv, ok := v.(*localVolume)
|
2015-05-19 16:05:25 -04:00
|
|
|
if !ok {
|
2016-03-16 17:52:34 -04:00
|
|
|
return fmt.Errorf("unknown volume type %T", v)
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
2015-06-03 12:26:41 -04:00
|
|
|
|
2015-06-12 09:25:32 -04:00
|
|
|
realPath, err := filepath.EvalSymlinks(lv.path)
|
|
|
|
if err != nil {
|
2015-09-08 22:01:02 -04:00
|
|
|
if !os.IsNotExist(err) {
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
realPath = filepath.Dir(lv.path)
|
2015-06-12 09:25:32 -04:00
|
|
|
}
|
2015-09-08 22:01:02 -04:00
|
|
|
|
2015-06-12 09:25:32 -04:00
|
|
|
if !r.scopedPath(realPath) {
|
2015-09-08 22:01:02 -04:00
|
|
|
return fmt.Errorf("Unable to remove a directory of out the Docker root %s: %s", r.scope, realPath)
|
2015-06-12 09:25:32 -04:00
|
|
|
}
|
2015-06-03 12:26:41 -04:00
|
|
|
|
2015-09-08 22:01:02 -04:00
|
|
|
if err := removePath(realPath); err != nil {
|
2015-06-12 09:25:32 -04:00
|
|
|
return err
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
2015-06-12 09:25:32 -04:00
|
|
|
|
|
|
|
delete(r.volumes, lv.name)
|
2015-09-08 22:01:02 -04:00
|
|
|
return removePath(filepath.Dir(lv.path))
|
|
|
|
}
|
|
|
|
|
|
|
|
func removePath(path string) error {
|
|
|
|
if err := os.RemoveAll(path); err != nil {
|
|
|
|
if os.IsNotExist(err) {
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
return nil
|
2015-06-12 09:25:32 -04:00
|
|
|
}
|
|
|
|
|
|
|
|
// Get looks up the volume for the given name and returns it if found
|
|
|
|
func (r *Root) Get(name string) (volume.Volume, error) {
|
|
|
|
r.m.Lock()
|
|
|
|
v, exists := r.volumes[name]
|
|
|
|
r.m.Unlock()
|
|
|
|
if !exists {
|
|
|
|
return nil, ErrNotFound
|
|
|
|
}
|
|
|
|
return v, nil
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
|
|
|
|
2015-10-20 13:09:48 -04:00
|
|
|
func (r *Root) validateName(name string) error {
|
|
|
|
if !volumeNameRegex.MatchString(name) {
|
Remove static errors from errors package.
Moving all strings to the errors package wasn't a good idea after all.
Our custom implementation of Go errors predates everything that's nice
and good about working with errors in Go. Take as an example what we
have to do to get an error message:
```go
func GetErrorMessage(err error) string {
switch err.(type) {
case errcode.Error:
e, _ := err.(errcode.Error)
return e.Message
case errcode.ErrorCode:
ec, _ := err.(errcode.ErrorCode)
return ec.Message()
default:
return err.Error()
}
}
```
This goes against every good practice for Go development. The language already provides a simple, intuitive and standard way to get error messages, that is calling the `Error()` method from an error. Reinventing the error interface is a mistake.
Our custom implementation also makes very hard to reason about errors, another nice thing about Go. I found several (>10) error declarations that we don't use anywhere. This is a clear sign about how little we know about the errors we return. I also found several error usages where the number of arguments was different than the parameters declared in the error, another clear example of how difficult is to reason about errors.
Moreover, our custom implementation didn't really make easier for people to return custom HTTP status code depending on the errors. Again, it's hard to reason about when to set custom codes and how. Take an example what we have to do to extract the message and status code from an error before returning a response from the API:
```go
switch err.(type) {
case errcode.ErrorCode:
daError, _ := err.(errcode.ErrorCode)
statusCode = daError.Descriptor().HTTPStatusCode
errMsg = daError.Message()
case errcode.Error:
// For reference, if you're looking for a particular error
// then you can do something like :
// import ( derr "github.com/docker/docker/errors" )
// if daError.ErrorCode() == derr.ErrorCodeNoSuchContainer { ... }
daError, _ := err.(errcode.Error)
statusCode = daError.ErrorCode().Descriptor().HTTPStatusCode
errMsg = daError.Message
default:
// This part of will be removed once we've
// converted everything over to use the errcode package
// FIXME: this is brittle and should not be necessary.
// If we need to differentiate between different possible error types,
// we should create appropriate error types with clearly defined meaning
errStr := strings.ToLower(err.Error())
for keyword, status := range map[string]int{
"not found": http.StatusNotFound,
"no such": http.StatusNotFound,
"bad parameter": http.StatusBadRequest,
"conflict": http.StatusConflict,
"impossible": http.StatusNotAcceptable,
"wrong login/password": http.StatusUnauthorized,
"hasn't been activated": http.StatusForbidden,
} {
if strings.Contains(errStr, keyword) {
statusCode = status
break
}
}
}
```
You can notice two things in that code:
1. We have to explain how errors work, because our implementation goes against how easy to use Go errors are.
2. At no moment we arrived to remove that `switch` statement that was the original reason to use our custom implementation.
This change removes all our status errors from the errors package and puts them back in their specific contexts.
IT puts the messages back with their contexts. That way, we know right away when errors used and how to generate their messages.
It uses custom interfaces to reason about errors. Errors that need to response with a custom status code MUST implementent this simple interface:
```go
type errorWithStatus interface {
HTTPErrorStatusCode() int
}
```
This interface is very straightforward to implement. It also preserves Go errors real behavior, getting the message is as simple as using the `Error()` method.
I included helper functions to generate errors that use custom status code in `errors/errors.go`.
By doing this, we remove the hard dependency we have eeverywhere to our custom errors package. Yes, you can use it as a helper to generate error, but it's still very easy to generate errors without it.
Please, read this fantastic blog post about errors in Go: http://dave.cheney.net/2014/12/24/inspecting-errors
Signed-off-by: David Calavera <david.calavera@gmail.com>
2016-02-25 10:53:35 -05:00
|
|
|
return validationError{fmt.Errorf("%q includes invalid characters for a local volume name, only %q are allowed", name, utils.RestrictedNameChars)}
|
2015-10-20 13:09:48 -04:00
|
|
|
}
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// localVolume implements the Volume interface from the volume package and
|
|
|
|
// represents the volumes created by Root.
|
|
|
|
type localVolume struct {
|
2016-04-14 03:04:00 -04:00
|
|
|
m sync.Mutex
|
2015-05-19 16:05:25 -04:00
|
|
|
// unique name of the volume
|
|
|
|
name string
|
|
|
|
// path is the path on the host where the data lives
|
|
|
|
path string
|
|
|
|
// driverName is the name of the driver that created the volume.
|
|
|
|
driverName string
|
2016-02-11 21:48:16 -05:00
|
|
|
// opts is the parsed list of options used to create the volume
|
|
|
|
opts *optsConfig
|
|
|
|
// active refcounts the active mounts
|
|
|
|
active activeMount
|
2015-05-19 16:05:25 -04:00
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Name returns the name of the given Volume.
|
|
|
|
func (v *localVolume) Name() string {
|
2015-05-19 16:05:25 -04:00
|
|
|
return v.name
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// DriverName returns the driver that created the given Volume.
|
|
|
|
func (v *localVolume) DriverName() string {
|
2015-05-19 16:05:25 -04:00
|
|
|
return v.driverName
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Path returns the data location.
|
|
|
|
func (v *localVolume) Path() string {
|
2015-05-19 16:05:25 -04:00
|
|
|
return v.path
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Mount implements the localVolume interface, returning the data location.
|
2016-03-07 21:41:44 -05:00
|
|
|
func (v *localVolume) Mount(id string) (string, error) {
|
2016-02-11 21:48:16 -05:00
|
|
|
v.m.Lock()
|
|
|
|
defer v.m.Unlock()
|
|
|
|
if v.opts != nil {
|
|
|
|
if !v.active.mounted {
|
|
|
|
if err := v.mount(); err != nil {
|
|
|
|
return "", err
|
|
|
|
}
|
|
|
|
v.active.mounted = true
|
|
|
|
}
|
|
|
|
v.active.count++
|
|
|
|
}
|
2015-05-19 16:05:25 -04:00
|
|
|
return v.path, nil
|
|
|
|
}
|
|
|
|
|
2015-07-21 13:50:10 -04:00
|
|
|
// Umount is for satisfying the localVolume interface and does not do anything in this driver.
|
2016-03-07 21:41:44 -05:00
|
|
|
func (v *localVolume) Unmount(id string) error {
|
2016-02-11 21:48:16 -05:00
|
|
|
v.m.Lock()
|
|
|
|
defer v.m.Unlock()
|
|
|
|
if v.opts != nil {
|
|
|
|
v.active.count--
|
|
|
|
if v.active.count == 0 {
|
|
|
|
if err := mount.Unmount(v.path); err != nil {
|
|
|
|
v.active.count++
|
|
|
|
return err
|
|
|
|
}
|
|
|
|
v.active.mounted = false
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return nil
|
|
|
|
}
|
|
|
|
|
|
|
|
func validateOpts(opts map[string]string) error {
|
|
|
|
for opt := range opts {
|
|
|
|
if !validOpts[opt] {
|
|
|
|
return validationError{fmt.Errorf("invalid option key: %q", opt)}
|
|
|
|
}
|
|
|
|
}
|
2015-05-19 16:05:25 -04:00
|
|
|
return nil
|
|
|
|
}
|
2016-03-07 15:44:43 -05:00
|
|
|
|
|
|
|
func (v *localVolume) Status() map[string]interface{} {
|
|
|
|
return nil
|
|
|
|
}
|