Documentation

Overview

    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 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

    Constants

    View Source
    const ProtocolSchemeHTTPV1 = "moby.plugins.http/v1"

      ProtocolSchemeHTTPV1 is the name of the protocol used for interacting with plugins using this package.

      Variables

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

            func WithRequestTimeout

            func WithRequestTimeout(t time.Duration) func(*RequestOpts)

              WithRequestTimeout sets a timeout duration for plugin requests

              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, 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) CallWithOptions

                      func (c *Client) CallWithOptions(serviceMethod string, args interface{}, ret interface{}, opts ...func(*RequestOpts)) error

                        CallWithOptions is just like call except it takes options

                        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) 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.

                                            func (*Plugin) Protocol

                                            func (p *Plugin) Protocol() string

                                              Protocol returns the protocol name/version used for plugins in this package.

                                              func (*Plugin) ScopedPath

                                              func (p *Plugin) ScopedPath(s string) string

                                                ScopedPath returns the path scoped to the plugin's rootfs. For v1 plugins, this always returns the path unchanged as v1 plugins run directly on the host.

                                                type RequestOpts

                                                type RequestOpts struct {
                                                	Timeout time.Duration
                                                }

                                                  RequestOpts is the set of options that can be passed into a request

                                                  Directories

                                                  Path Synopsis