package plugins

import "github.com/docker/cli/components/engine/pkg/plugins"

Package plugins provides structures and helper functions to manage Docker plugins.

Docker discovers plugins by looking for them in the plugin directory whenever a user or container tries to use one by name. UNIX domain socket files must be located under /run/docker/plugins, whereas spec files can be located either under /etc/docker/plugins or /usr/lib/docker/plugins. This is handled by the Registry interface, which lets you list all plugins or get a plugin by its name if it exists.

The plugins need to implement an HTTP server and bind this to the UNIX socket or the address specified in the spec files. A handshake is send at /Plugin.Activate, and plugins are expected to return a Manifest with a list of of Docker subsystems which this plugin implements.

In order to use a plugins, you can use the “Get“ with the name of the plugin and the subsystem it implements.

plugin, err := plugins.Get("example", "VolumeDriver")
if err != nil {
	return fmt.Errorf("Error looking up volume plugin example: %v", err)
}

Index ¶

• Variables
• func Handle(iface string, fn func(string, *Client))
• func IsNotFound(err error) bool
• func Scan() ([]string, error)
• type Client
• func NewClient(addr string, tlsConfig *tlsconfig.Options) (*Client, error)
• func NewClientWithTimeout(addr string, tlsConfig *tlsconfig.Options, timeout time.Duration) (*Client, error)
• func (c *Client) Call(serviceMethod string, args interface{}, ret interface{}) error
• func (c *Client) SendFile(serviceMethod string, data io.Reader, ret interface{}) error
• func (c *Client) Stream(serviceMethod string, args interface{}) (io.ReadCloser, error)
• type Manifest
• type Plugin
• func Get(name, imp string) (*Plugin, error)
• func GetAll(imp string) ([]*Plugin, error)
• func NewLocalPlugin(name, addr string) *Plugin
• func (p *Plugin) BasePath() string
• func (p *Plugin) Client() *Client
• func (p *Plugin) IsV1() bool
• func (p *Plugin) Name() string

Variables ¶

var (
	// ErrNotFound plugin not found
	ErrNotFound = errors.New("plugin not found")
)

var (
	// ErrNotImplements is returned if the plugin does not implement the requested driver.
	ErrNotImplements = errors.New("Plugin does not implement the requested driver")
)

Functions ¶

func Handle ¶

func Handle(iface string, fn func(string, *Client))

Handle adds the specified function to the extpointHandlers.

func IsNotFound ¶

func IsNotFound(err error) bool

IsNotFound indicates if the passed in error is from an http.StatusNotFound from the plugin

func Scan ¶

func Scan() ([]string, error)

Scan scans all the plugin paths and returns all the names it found

Types ¶

type Client ¶

type Client struct {
	// contains filtered or unexported fields
}

Client represents a plugin client.

func NewClient ¶

func NewClient(addr string, tlsConfig *tlsconfig.Options) (*Client, error)

NewClient creates a new plugin client (http).

func NewClientWithTimeout ¶

func NewClientWithTimeout(addr string, tlsConfig *tlsconfig.Options, timeout time.Duration) (*Client, error)

NewClientWithTimeout creates a new plugin client (http).

func (*Client) Call ¶

func (c *Client) Call(serviceMethod string, args interface{}, ret interface{}) error

Call calls the specified method with the specified arguments for the plugin. It will retry for 30 seconds if a failure occurs when calling.

func (*Client) SendFile ¶

func (c *Client) SendFile(serviceMethod string, data io.Reader, ret interface{}) error

SendFile calls the specified method, and passes through the IO stream

func (*Client) Stream ¶

func (c *Client) Stream(serviceMethod string, args interface{}) (io.ReadCloser, error)

Stream calls the specified method with the specified arguments for the plugin and returns the response body

type Manifest ¶

type Manifest struct {
	// List of subsystem the plugin implements.
	Implements []string
}

Manifest lists what a plugin implements.

type Plugin ¶

type Plugin struct {

	// Address of the plugin
	Addr string
	// TLS configuration of the plugin
	TLSConfig *tlsconfig.Options

	// Manifest of the plugin (see above)
	Manifest *Manifest `json:"-"`
	// contains filtered or unexported fields
}

Plugin is the definition of a docker plugin.

func Get ¶

func Get(name, imp string) (*Plugin, error)

Get returns the plugin given the specified name and requested implementation.

func GetAll ¶

func GetAll(imp string) ([]*Plugin, error)

GetAll returns all the plugins for the specified implementation

func NewLocalPlugin ¶

func NewLocalPlugin(name, addr string) *Plugin

NewLocalPlugin creates a new local plugin.

func (*Plugin) BasePath ¶

func (p *Plugin) BasePath() string

BasePath returns the path to which all paths returned by the plugin are relative to. For Windows v1 plugins, this returns an empty string, since the plugin is already aware of the absolute path of the mount.

func (*Plugin) Client ¶

func (p *Plugin) Client() *Client

Client returns a ready-to-use plugin client that can be used to communicate with the plugin.

func (*Plugin) IsV1 ¶

func (p *Plugin) IsV1() bool

IsV1 returns true for V1 plugins and false otherwise.

func (*Plugin) Name ¶

func (p *Plugin) Name() string

Name returns the name of the plugin.

Source Files ¶

client.go discovery.go discovery_windows.go errors.go plugins.go plugins_windows.go

Directories ¶