| //go:generate pluginrpc-gen -i $GOFILE -o proxy.go -type volumeDriver -name VolumeDriver |
| |
| package volumedrivers |
| |
| import ( |
| "fmt" |
| "sort" |
| "sync" |
| |
| "github.com/docker/docker/pkg/locker" |
| getter "github.com/docker/docker/pkg/plugingetter" |
| "github.com/docker/docker/volume" |
| "github.com/pkg/errors" |
| "github.com/sirupsen/logrus" |
| ) |
| |
| // currently created by hand. generation tool would generate this like: |
| // $ extpoint-gen Driver > volume/extpoint.go |
| |
| var drivers = &driverExtpoint{ |
| extensions: make(map[string]volume.Driver), |
| driverLock: &locker.Locker{}, |
| } |
| |
| const extName = "VolumeDriver" |
| |
| // NewVolumeDriver returns a driver has the given name mapped on the given client. |
| func NewVolumeDriver(name string, baseHostPath string, c client) volume.Driver { |
| proxy := &volumeDriverProxy{c} |
| return &volumeDriverAdapter{name: name, baseHostPath: baseHostPath, proxy: proxy} |
| } |
| |
| // volumeDriver defines the available functions that volume plugins must implement. |
| // This interface is only defined to generate the proxy objects. |
| // It's not intended to be public or reused. |
| // nolint: deadcode |
| type volumeDriver interface { |
| // Create a volume with the given name |
| Create(name string, opts map[string]string) (err error) |
| // Remove the volume with the given name |
| Remove(name string) (err error) |
| // Get the mountpoint of the given volume |
| Path(name string) (mountpoint string, err error) |
| // Mount the given volume and return the mountpoint |
| Mount(name, id string) (mountpoint string, err error) |
| // Unmount the given volume |
| Unmount(name, id string) (err error) |
| // List lists all the volumes known to the driver |
| List() (volumes []*proxyVolume, err error) |
| // Get retrieves the volume with the requested name |
| Get(name string) (volume *proxyVolume, err error) |
| // Capabilities gets the list of capabilities of the driver |
| Capabilities() (capabilities volume.Capability, err error) |
| } |
| |
| type driverExtpoint struct { |
| extensions map[string]volume.Driver |
| sync.Mutex |
| driverLock *locker.Locker |
| plugingetter getter.PluginGetter |
| } |
| |
| // RegisterPluginGetter sets the plugingetter |
| func RegisterPluginGetter(plugingetter getter.PluginGetter) { |
| drivers.plugingetter = plugingetter |
| } |
| |
| // Register associates the given driver to the given name, checking if |
| // the name is already associated |
| func Register(extension volume.Driver, name string) bool { |
| if name == "" { |
| return false |
| } |
| |
| drivers.Lock() |
| defer drivers.Unlock() |
| |
| _, exists := drivers.extensions[name] |
| if exists { |
| return false |
| } |
| |
| if err := validateDriver(extension); err != nil { |
| return false |
| } |
| |
| drivers.extensions[name] = extension |
| |
| return true |
| } |
| |
| // Unregister dissociates the name from its driver, if the association exists. |
| func Unregister(name string) bool { |
| drivers.Lock() |
| defer drivers.Unlock() |
| |
| _, exists := drivers.extensions[name] |
| if !exists { |
| return false |
| } |
| delete(drivers.extensions, name) |
| return true |
| } |
| |
| type driverNotFoundError string |
| |
| func (e driverNotFoundError) Error() string { |
| return "volume driver not found: " + string(e) |
| } |
| |
| func (driverNotFoundError) NotFound() {} |
| |
| // lookup returns the driver associated with the given name. If a |
| // driver with the given name has not been registered it checks if |
| // there is a VolumeDriver plugin available with the given name. |
| func lookup(name string, mode int) (volume.Driver, error) { |
| drivers.driverLock.Lock(name) |
| defer drivers.driverLock.Unlock(name) |
| |
| drivers.Lock() |
| ext, ok := drivers.extensions[name] |
| drivers.Unlock() |
| if ok { |
| return ext, nil |
| } |
| if drivers.plugingetter != nil { |
| p, err := drivers.plugingetter.Get(name, extName, mode) |
| if err != nil { |
| return nil, errors.Wrap(err, "error looking up volume plugin "+name) |
| } |
| |
| d := NewVolumeDriver(p.Name(), p.BasePath(), p.Client()) |
| if err := validateDriver(d); err != nil { |
| if mode > 0 { |
| // Undo any reference count changes from the initial `Get` |
| if _, err := drivers.plugingetter.Get(name, extName, mode*-1); err != nil { |
| logrus.WithError(err).WithField("action", "validate-driver").WithField("plugin", name).Error("error releasing reference to plugin") |
| } |
| } |
| return nil, err |
| } |
| |
| if p.IsV1() { |
| drivers.Lock() |
| drivers.extensions[name] = d |
| drivers.Unlock() |
| } |
| return d, nil |
| } |
| return nil, driverNotFoundError(name) |
| } |
| |
| func validateDriver(vd volume.Driver) error { |
| scope := vd.Scope() |
| if scope != volume.LocalScope && scope != volume.GlobalScope { |
| return fmt.Errorf("Driver %q provided an invalid capability scope: %s", vd.Name(), scope) |
| } |
| return nil |
| } |
| |
| // GetDriver returns a volume driver by its name. |
| // If the driver is empty, it looks for the local driver. |
| func GetDriver(name string) (volume.Driver, error) { |
| if name == "" { |
| name = volume.DefaultDriverName |
| } |
| return lookup(name, getter.Lookup) |
| } |
| |
| // CreateDriver returns a volume driver by its name and increments RefCount. |
| // If the driver is empty, it looks for the local driver. |
| func CreateDriver(name string) (volume.Driver, error) { |
| if name == "" { |
| name = volume.DefaultDriverName |
| } |
| return lookup(name, getter.Acquire) |
| } |
| |
| // ReleaseDriver returns a volume driver by its name and decrements RefCount.. |
| // If the driver is empty, it looks for the local driver. |
| func ReleaseDriver(name string) (volume.Driver, error) { |
| if name == "" { |
| name = volume.DefaultDriverName |
| } |
| return lookup(name, getter.Release) |
| } |
| |
| // GetDriverList returns list of volume drivers registered. |
| // If no driver is registered, empty string list will be returned. |
| func GetDriverList() []string { |
| var driverList []string |
| drivers.Lock() |
| for driverName := range drivers.extensions { |
| driverList = append(driverList, driverName) |
| } |
| drivers.Unlock() |
| sort.Strings(driverList) |
| return driverList |
| } |
| |
| // GetAllDrivers lists all the registered drivers |
| func GetAllDrivers() ([]volume.Driver, error) { |
| var plugins []getter.CompatPlugin |
| if drivers.plugingetter != nil { |
| var err error |
| plugins, err = drivers.plugingetter.GetAllByCap(extName) |
| if err != nil { |
| return nil, fmt.Errorf("error listing plugins: %v", err) |
| } |
| } |
| var ds []volume.Driver |
| |
| drivers.Lock() |
| defer drivers.Unlock() |
| |
| for _, d := range drivers.extensions { |
| ds = append(ds, d) |
| } |
| |
| for _, p := range plugins { |
| name := p.Name() |
| |
| if _, ok := drivers.extensions[name]; ok { |
| continue |
| } |
| |
| ext := NewVolumeDriver(name, p.BasePath(), p.Client()) |
| if p.IsV1() { |
| drivers.extensions[name] = ext |
| } |
| ds = append(ds, ext) |
| } |
| return ds, nil |
| } |