README ¶
Volume Drivers
Volume drivers implement the Volume Plugin Interface. This provides an interface to register a volume driver and advertise the driver to Docker. Registering a driver with this volume interface will cause Docker to be able to communicate with the driver to create and assign volumes to a container.
A volume spec is needed to create a volume. A volume spec looks like:
// VolumeSpec has the properties needed to create a volume.
type VolumeSpec struct {
// Ephemeral storage
Ephemeral bool
// Thin provisioned volume size in bytes
Size uint64
// Format disk with this FileSystem
Format Filesystem
// BlockSize for file system
BlockSize int
// HA Level specifies the number of nodes that are
// allowed to fail, and yet data is availabel.
// A value of 0 implies that data is not erasure coded,
// a failure of a node will lead to data loss.
HALevel int
// This disk's CoS
Cos VolumeCos
// Perform dedupe on this disk
Dedupe bool
// SnapshotInterval in minutes, set to 0 to disable Snapshots
SnapshotInterval int
// Volume configuration labels
ConfigLabels Labels
}
Various volume driver implementations can be found in the drivers
directory.
Block Drivers
Block drivers operate at the block layer. They provide raw volumes formatted with a user specified filesystem. This volume is then mounted into the container at a path specified using the docker run -v
option.
File Drivers
File drivers operate at the filesystem layer.
Documentation ¶
Index ¶
- Constants
- Variables
- func CloudBackupWaitForCompletion(cl CloudBackupDriver, taskId string, opType api.CloudBackupOpType) error
- func NewCredentialError(msg string) error
- type BlockDriver
- type CloudBackupDriver
- type CloudMigrateDriver
- type CredentialError
- type CredsDriver
- type Enumerator
- type FilesystemCheckDriver
- type FilesystemTrimDriver
- type IODriver
- type ProtoDriver
- type QuiesceDriver
- type SnapshotDriver
- type StatsDriver
- type Store
- type StoreEnumerator
- type VolumeDriver
- type VolumeDriverProvider
- type VolumeDriverRegistry
Constants ¶
const ( // APIVersion for the volume management apis APIVersion = "v1" // PluginAPIBase where the docker unix socket resides PluginAPIBase = "/run/docker/plugins/" // DriverAPIBase where the osd unix socket resides DriverAPIBase = "/var/lib/osd/driver/" // MountBase for osd mountpoints MountBase = "/var/lib/osd/mounts/" // VolumeBase for osd volumes VolumeBase = "/var/lib/osd/" )
Constants used by the VolumeDriver
const ( // LocationConstaint is a label that specifies data location constraint. LocationConstraint = "LocationConstraint" // LocalNode is an alias for this node - similar to localhost. LocalNode = "LocalNode" )
Variables ¶
var ( // ErrAlreadyShutdown returned when driver is shutdown ErrAlreadyShutdown = errors.New("VolumeDriverProvider already shutdown") // ErrExit returned when driver already registered ErrExist = errors.New("Already exists") // ErrDriverNotFound returned when a driver is not registered ErrDriverNotFound = errors.New("Driver implementation not found") // ErrDriverInitializing returned when a driver is initializing ErrDriverInitializing = errors.New("Driver is initializing") // ErrEnoEnt returned when volume does not exist ErrEnoEnt = errors.New("Volume does not exist.") // ErrEnomem returned when we are out of memory ErrEnomem = errors.New("Out of memory.") // ErrEinval returned when an invalid input is provided ErrEinval = errors.New("Invalid argument") // ErrVolDetached returned when volume is in detached state ErrVolDetached = errors.New("Volume is detached") // ErrVolAttached returned when volume is in attached state ErrVolAttached = errors.New("Volume is attached") // ErrVolAttachedOnRemoteNode returned when volume is in attached on different node ErrVolAttachedOnRemoteNode = errors.New("Volume is attached on another node") // ErrVolAttachedScale returned when volume is attached and can be scaled ErrVolAttachedScale = errors.New("Volume is attached on another node." + " Increase scale factor to create more instances") // ErrVolHasSnaps returned when volume has previous snapshots ErrVolHasSnaps = errors.New("Volume has snapshots associated") // ErrNotSupported returned when the operation is not supported ErrNotSupported = errors.New("Operation not supported") // ErrVolBusy returned when volume is in busy state ErrVolBusy = errors.New("Volume is busy") // ErrAborted returned when capacityUsageInfo cannot be returned ErrAborted = errors.New("Aborted CapacityUsage request") // ErrInvalidName returned when Cloudbackup Name/request is invalid ErrInvalidName = errors.New("Invalid name for cloud backup/restore request") // ErrFsResizeFailed returned when Filesystem resize failed because of filesystem // errors ErrFsResizeFailed = errors.New("Filesystem Resize failed due to filesystem errors") // ErrNoVolumeUpdate is returned when a volume update has no changes requested ErrNoVolumeUpdate = errors.New("No change requested") )
var ( // BlockNotSupported is a default (null) block driver implementation. This can be // used by drivers that do not want to (or care about) implementing the attach, // format and detach interfaces. BlockNotSupported = &blockNotSupported{} // SnapshotNotSupported is a null snapshot driver implementation. This can be used // by drivers that do not want to implement the snapshot interface SnapshotNotSupported = &snapshotNotSupported{} // IONotSupported is a null IODriver interface IONotSupported = &ioNotSupported{} // StatsNotSupported is a null stats driver implementation. This can be used // by drivers that do not want to implement the stats interface. StatsNotSupported = &statsNotSupported{} // QuiesceNotSupported implements quiesce/unquiesce by returning not // supported error. QuiesceNotSupported = &quiesceNotSupported{} // CredsNotSupported implements credentials by returning not supported error CredsNotSupported = &credsNotSupported{} // CloudBackupNotSupported implements cloudBackupDriver by returning // Not supported error CloudBackupNotSupported = &cloudBackupNotSupported{} // CloudMigrateNotSupported implements cloudMigrateDriver by returning // Not supported error CloudMigrateNotSupported = &cloudMigrateNotSupported{} // FilesystemTrimNotSupported implements FilesystemTrimDriver by returning // Not supported error FilesystemTrimNotSupported = &filesystemTrimNotSupported{} // FilesystemCheckNotSupported implements FilesystemCheckDriver by returning // Not supported error FilesystemCheckNotSupported = &filesystemCheckNotSupported{} )
Functions ¶
func CloudBackupWaitForCompletion ¶
func CloudBackupWaitForCompletion( cl CloudBackupDriver, taskId string, opType api.CloudBackupOpType, ) error
func NewCredentialError ¶
Types ¶
type BlockDriver ¶
type BlockDriver interface { // Attach map device to the host. // On success the devicePath specifies location where the device is exported // Errors ErrEnoEnt, ErrVolAttached may be returned. Attach(volumeID string, attachOptions map[string]string) (string, error) // Detach device from the host. // Errors ErrEnoEnt, ErrVolDetached may be returned. Detach(volumeID string, options map[string]string) error }
BlockDriver needs to be implemented by block volume drivers. Filesystem volume drivers can ignore this interface and include the builtin DefaultBlockDriver.
type CloudBackupDriver ¶
type CloudBackupDriver interface { // CloudBackupCreate uploads snapshot of a volume to the cloud CloudBackupCreate(input *api.CloudBackupCreateRequest) (*api.CloudBackupCreateResponse, error) // CloudBackupGroupCreate creates and then uploads volumegroup snapshots CloudBackupGroupCreate(input *api.CloudBackupGroupCreateRequest) (*api.CloudBackupGroupCreateResponse, error) // CloudBackupRestore downloads a cloud backup and restores it to a volume CloudBackupRestore(input *api.CloudBackupRestoreRequest) (*api.CloudBackupRestoreResponse, error) // CloudBackupEnumerate enumerates the backups for a given cluster/credential/volumeID CloudBackupEnumerate(input *api.CloudBackupEnumerateRequest) (*api.CloudBackupEnumerateResponse, error) // CloudBackupDelete deletes the specified backup in cloud CloudBackupDelete(input *api.CloudBackupDeleteRequest) error // CloudBackupDelete deletes all the backups for a given volume in cloud CloudBackupDeleteAll(input *api.CloudBackupDeleteAllRequest) error // CloudBackupStatus indicates the most recent status of backup/restores CloudBackupStatus(input *api.CloudBackupStatusRequest) (*api.CloudBackupStatusResponse, error) // CloudBackupCatalog displays listing of backup content CloudBackupCatalog(input *api.CloudBackupCatalogRequest) (*api.CloudBackupCatalogResponse, error) // CloudBackupHistory displays past backup/restore operations on a volume CloudBackupHistory(input *api.CloudBackupHistoryRequest) (*api.CloudBackupHistoryResponse, error) // CloudBackupStateChange allows a current backup state transisions(pause/resume/stop) CloudBackupStateChange(input *api.CloudBackupStateChangeRequest) error // CloudBackupSchedCreate creates a schedule to backup volume to cloud CloudBackupSchedCreate(input *api.CloudBackupSchedCreateRequest) (*api.CloudBackupSchedCreateResponse, error) // CloudBackupGroupSchedCreate creates a schedule to backup a volumegroup to cloud CloudBackupGroupSchedCreate(input *api.CloudBackupGroupSchedCreateRequest) (*api.CloudBackupSchedCreateResponse, error) // CloudBackupSchedCreate creates a schedule to backup volume to cloud CloudBackupSchedUpdate(input *api.CloudBackupSchedUpdateRequest) error // CloudBackupGroupSchedCreate creates a schedule to backup a volumegroup to cloud CloudBackupGroupSchedUpdate(input *api.CloudBackupGroupSchedUpdateRequest) error // CloudBackupSchedDelete delete a backup schedule CloudBackupSchedDelete(input *api.CloudBackupSchedDeleteRequest) error // CloudBackupSchedEnumerate enumerates the configured backup schedules in the cluster CloudBackupSchedEnumerate() (*api.CloudBackupSchedEnumerateResponse, error) // CloudBackupSize fetches the size of a cloud backup CloudBackupSize(input *api.SdkCloudBackupSizeRequest) (*api.SdkCloudBackupSizeResponse, error) }
CloudBackupDriver interface provides Cloud backup features
type CloudMigrateDriver ¶
type CloudMigrateDriver interface { // CloudMigrateStart starts a migrate operation CloudMigrateStart(request *api.CloudMigrateStartRequest) (*api.CloudMigrateStartResponse, error) // CloudMigrateCancel cancels a migrate operation CloudMigrateCancel(request *api.CloudMigrateCancelRequest) error // CloudMigrateStatus returns status for the migration operations CloudMigrateStatus(request *api.CloudMigrateStatusRequest) (*api.CloudMigrateStatusResponse, error) }
CloudMigrateDriver interface provides Cloud migration features
type CredentialError ¶
type CredentialError struct { // Msg is human understandable error message Msg string }
CredentialError error returned for credential operations
func (*CredentialError) Error ¶
func (e *CredentialError) Error() string
type CredsDriver ¶
type CredsDriver interface { // CredsCreate creates credential for a given cloud provider CredsCreate(params map[string]string) (string, error) // CredsList lists the configured credentials in the cluster CredsEnumerate() (map[string]interface{}, error) // CredsDelete deletes the credential associated credUUID CredsDelete(credUUID string) error // CredsValidate validates the credential associated credUUID CredsValidate(credUUID string) error // CredsDeleteReferences delets any with the creds CredsDeleteReferences(credUUID string) error }
CredsDriver provides methods to handle credentials
type Enumerator ¶
type Enumerator interface { // Inspect specified volumes. // Returns slice of volumes that were found. Inspect(volumeIDs []string) ([]*api.Volume, error) // Enumerate volumes that map to the volumeLocator. Locator fields may be regexp. // If locator fields are left blank, this will return all volumes. Enumerate(locator *api.VolumeLocator, labels map[string]string) ([]*api.Volume, error) // Enumerate snaps for specified volumes SnapEnumerate(volID []string, snapLabels map[string]string) ([]*api.Volume, error) }
Enumerator provides a set of interfaces to get details on a set of volumes.
type FilesystemCheckDriver ¶
type FilesystemCheckDriver interface { // FilesystemCheckStart starts a filesystem check background operation // on a specified volume FilesystemCheckStart(request *api.SdkFilesystemCheckStartRequest) (*api.SdkFilesystemCheckStartResponse, error) // FilesystemCheckStatus returns the status of a filesystem check // background operation on the filesystem of a specified volume, if any. FilesystemCheckStatus(request *api.SdkFilesystemCheckStatusRequest) (*api.SdkFilesystemCheckStatusResponse, error) // FilesystemCheckStop stops the filesystem check background operation on // the filesystem of a specified volume, if any. FilesystemCheckStop(request *api.SdkFilesystemCheckStopRequest) (*api.SdkFilesystemCheckStopResponse, error) }
FilesystemCheckDriver interface exposes APIs to manage filesystem check operation on a volume
type FilesystemTrimDriver ¶
type FilesystemTrimDriver interface { // FilesystemTrimStart starts a filesystem trim background operation on a // specified volume FilesystemTrimStart(request *api.SdkFilesystemTrimStartRequest) (*api.SdkFilesystemTrimStartResponse, error) // FilesystemTrimStatus returns the status of a filesystem trim // background operation on a specified volume, if any FilesystemTrimStatus(request *api.SdkFilesystemTrimStatusRequest) (*api.SdkFilesystemTrimStatusResponse, error) // FilesystemTrimStop stops a filesystem trim background operation on // a specified volume, if any FilesystemTrimStop(request *api.SdkFilesystemTrimStopRequest) (*api.SdkFilesystemTrimStopResponse, error) }
FilesystemTrimDriver interface exposes APIs to manage filesystem trim operation on a volume
type IODriver ¶
type IODriver interface { // Read sz bytes from specified volume at specified offset. // Return number of bytes read and error. Read(volumeID string, buf []byte, sz uint64, offset int64) (int64, error) // Write sz bytes from specified volume at specified offset. // Return number of bytes written and error. Write(volumeID string, buf []byte, sz uint64, offset int64) (int64, error) // Flush writes to stable storage. // Return error. Flush(volumeID string) error }
IODriver interfaces applicable to object store interfaces.
type ProtoDriver ¶
type ProtoDriver interface { SnapshotDriver StatsDriver QuiesceDriver CredsDriver CloudBackupDriver CloudMigrateDriver FilesystemTrimDriver FilesystemCheckDriver // Name returns the name of the driver. Name() string // Type of this driver Type() api.DriverType // Version information of the driver Version() (*api.StorageVersion, error) // Create a new Vol for the specific volume spec. // It returns a system generated VolumeID that uniquely identifies the volume Create(locator *api.VolumeLocator, Source *api.Source, spec *api.VolumeSpec) (string, error) // Delete volume. // Errors ErrEnoEnt, ErrVolHasSnaps may be returned. Delete(volumeID string) error // Mount volume at specified path // Errors ErrEnoEnt, ErrVolDetached may be returned. Mount(volumeID string, mountPath string, options map[string]string) error // MountedAt return volume mounted at specified mountpath. MountedAt(mountPath string) string // Unmount volume at specified path // Errors ErrEnoEnt, ErrVolDetached may be returned. Unmount(volumeID string, mountPath string, options map[string]string) error // Update not all fields of the spec are supported, ErrNotSupported will be thrown for unsupported // updates. Set(volumeID string, locator *api.VolumeLocator, spec *api.VolumeSpec) error // Status returns a set of key-value pairs which give low // level diagnostic status about this driver. Status() [][2]string // Shutdown and cleanup. Shutdown() // DU specified volume and potentially the subfolder if provided. Catalog(volumeid, subfolder string, depth string) (api.CatalogResponse, error) // Does a Filesystem Trim operation to free unused space to block device(block discard) VolService(volumeID string, vsreq *api.VolumeServiceRequest) (*api.VolumeServiceResponse, error) }
ProtoDriver must be implemented by all volume drivers. It specifies the most basic functionality, such as creating and deleting volumes.
type QuiesceDriver ¶
type QuiesceDriver interface { // Freezes mounted filesystem resulting in a quiesced volume state. // Only one freeze operation may be active at any given time per volume. // Unfreezes after timeout seconds if it is non-zero. // An optional quiesceID can be passed for driver-specific use. Quiesce(volumeID string, timeoutSeconds uint64, quiesceID string) error // Unfreezes mounted filesystem if it was frozen. Unquiesce(volumeID string) error }
type SnapshotDriver ¶
type SnapshotDriver interface { // Snapshot create volume snapshot. // Errors ErrEnoEnt may be returned Snapshot(volumeID string, readonly bool, locator *api.VolumeLocator, noRetry bool) (string, error) // Restore restores volume to specified snapshot. Restore(volumeID string, snapshotID string) error // SnapshotGroup takes a snapshot of a group of volumes that can be specified with either of the following // 1. group ID // 2. labels // 3. volumeIDs // deleteOnFailure indicates whether to delete the successful snaps if some of the snapshots failed SnapshotGroup(groupID string, labels map[string]string, volumeIDs []string, deleteOnFailure bool) (*api.GroupSnapCreateResponse, error) }
SnapshotDriver interfaces provides snapshot capability
type StatsDriver ¶
type StatsDriver interface { // Stats for specified volume. // cumulative stats are /proc/diskstats style stats. // nonCumulative stats are stats for specific duration. // Errors ErrEnoEnt may be returned Stats(volumeID string, cumulative bool) (*api.Stats, error) // UsedSize returns currently used volume size. // Errors ErrEnoEnt may be returned. UsedSize(volumeID string) (uint64, error) // GetActiveRequests get active requests GetActiveRequests() (*api.ActiveRequests, error) // CapacityUsage returns both exclusive and shared usage // of a snap/volume CapacityUsage(ID string) (*api.CapacityUsageResponse, error) // VolumeUsageByNode returns capacity usage of all volumes and snaps for a // given node VolumeUsageByNode(nodeID string) (*api.VolumeUsageByNode, error) }
StatsDriver interface provides stats features
type Store ¶
type Store interface { // Lock volume specified by volumeID. Lock(volumeID string) (interface{}, error) // Lock volume with token obtained from call to Lock. Unlock(token interface{}) error // CreateVol returns error if volume with the same ID already existe. CreateVol(vol *api.Volume) error // GetVol from volumeID. GetVol(volumeID string) (*api.Volume, error) // UpdateVol with vol UpdateVol(vol *api.Volume) error // DeleteVol. Returns error if volume does not exist. DeleteVol(volumeID string) error }
Store defines the interface for basic volume store operations
type StoreEnumerator ¶
type StoreEnumerator interface { Store Enumerator }
StoreEnumerator combines Store and Enumerator capabilities
type VolumeDriver ¶
type VolumeDriver interface { IODriver ProtoDriver BlockDriver Enumerator }
VolumeDriver is the main interface to be implemented by any storage driver. Every driver must at minimum implement the ProtoDriver sub interface.
type VolumeDriverProvider ¶
type VolumeDriverProvider interface { // Get gets the VolumeDriver for the given name. // If a VolumeDriver was not created for the given name, the error ErrDriverNotFound is returned. Get(name string) (VolumeDriver, error) // Shutdown shuts down all volume drivers. Shutdown() error }
VolumeDriverProvider provides VolumeDrivers.
type VolumeDriverRegistry ¶
type VolumeDriverRegistry interface { VolumeDriverProvider // New creates the VolumeDriver for the given name. // If a VolumeDriver was already created for the given name, the error ErrExist is returned. Register(name string, params map[string]string) error // Add inserts a new VolumeDriver provider with a well known name. Add(name string, init func(map[string]string) (VolumeDriver, error)) error // Removes driver from registry. Does nothing if driver name does not exist. Remove(name string) }
VolumeDriverRegistry registers VolumeDrivers.
func NewVolumeDriverRegistry ¶
func NewVolumeDriverRegistry(nameToInitFunc map[string]func(map[string]string) (VolumeDriver, error)) VolumeDriverRegistry
NewVolumeDriverRegistry constructs a new VolumeDriverRegistry.
Source Files ¶
Directories ¶
Path | Synopsis |
---|---|
buse
Package buse uses the Linux NBD layer to emulate a block device in user space
|
Package buse uses the Linux NBD layer to emulate a block device in user space |
fake
Package fake provides an in-memory fake driver implementation Copyright 2018 Portworx
|
Package fake provides an in-memory fake driver implementation Copyright 2018 Portworx |
mock
Package mock is a generated GoMock package.
|
Package mock is a generated GoMock package. |