d3d4423ff7
This removes documentation and code related to IPC based storage driver plugins. The existence of this functionality was an original feature goal but is now not maintained and actively confusing incoming contributions. We will likely explore some driver plugin mechanism in the future but we don't need this laying around in the meantime. Signed-off-by: Stephen J Day <stephen.day@docker.com>
59 lines
3.2 KiB
Markdown
59 lines
3.2 KiB
Markdown
<!--[metadata]>
|
|
+++
|
|
title = "Docker Registry Storage Driver"
|
|
description = "Explains how to use the storage drivers"
|
|
keywords = ["registry, service, driver, images, storage"]
|
|
[menu.main]
|
|
parent="smn_registry_ref"
|
|
identifier="smn_registry_drivers"
|
|
+++
|
|
<![end-metadata]-->
|
|
|
|
|
|
# Docker Registry Storage Driver
|
|
|
|
This document describes the registry storage driver model, implementation, and explains how to contribute new storage drivers.
|
|
|
|
## Provided Drivers
|
|
|
|
This storage driver package comes bundled with several drivers:
|
|
|
|
- [inmemory](storage-drivers/inmemory.md): A temporary storage driver using a local inmemory map. This exists solely for reference and testing.
|
|
- [filesystem](storage-drivers/filesystem.md): A local storage driver configured to use a directory tree in the local filesystem.
|
|
- [s3](storage-drivers/s3.md): A driver storing objects in an Amazon Simple Storage Solution (S3) bucket.
|
|
- [azure](storage-drivers/azure.md): A driver storing objects in [Microsoft Azure Blob Storage](http://azure.microsoft.com/en-us/services/storage/).
|
|
- [rados](storage-drivers/rados.md): A driver storing objects in a [Ceph Object Storage](http://ceph.com/docs/master/rados/) pool.
|
|
|
|
## Storage Driver API
|
|
|
|
The storage driver API is designed to model a filesystem-like key/value storage in a manner abstract enough to support a range of drivers from the local filesystem to Amazon S3 or other distributed object storage systems.
|
|
|
|
Storage drivers are required to implement the `storagedriver.StorageDriver` interface provided in `storagedriver.go`, which includes methods for reading, writing, and deleting content, as well as listing child objects of a specified prefix key.
|
|
|
|
Storage drivers are intended to be written in Go, providing compile-time
|
|
validation of the `storagedriver.StorageDriver` interface.
|
|
|
|
## Driver Selection and Configuration
|
|
|
|
The preferred method of selecting a storage driver is using the `StorageDriverFactory` interface in the `storagedriver/factory` package. These factories provide a common interface for constructing storage drivers with a parameters map. The factory model is based off of the [Register](http://golang.org/pkg/database/sql/#Register) and [Open](http://golang.org/pkg/database/sql/#Open) methods in the builtin [database/sql](http://golang.org/pkg/database/sql) package.
|
|
|
|
Storage driver factories may be registered by name using the
|
|
`factory.Register` method, and then later invoked by calling `factory.Create`
|
|
with a driver name and parameters map. If no such storage driver can be found,
|
|
`factory.Create` will return an `InvalidStorageDriverError`.
|
|
|
|
## Driver Contribution
|
|
|
|
### Writing new storage drivers
|
|
To create a valid storage driver, one must implement the
|
|
`storagedriver.StorageDriver` interface and make sure to expose this driver
|
|
via the factory system.
|
|
|
|
#### Registering
|
|
Storage drivers should call `factory.Register` with their driver name in an `init` method, allowing callers of `factory.New` to construct instances of this driver without requiring modification of imports throughout the codebase.
|
|
|
|
## Testing
|
|
Storage driver test suites are provided in
|
|
`storagedriver/testsuites/testsuites.go` and may be used for any storage
|
|
driver written in Go. Tests can be registered using the `RegisterSuite`
|
|
function, which run the same set of tests for any registered drivers.
|