open-nomad/vendor/github.com/hashicorp/go-plugin/plugin.go
2017-07-21 12:11:21 -07:00

57 lines
2 KiB
Go

// The plugin package exposes functions and helpers for communicating to
// plugins which are implemented as standalone binary applications.
//
// plugin.Client fully manages the lifecycle of executing the application,
// connecting to it, and returning the RPC client for dispensing plugins.
//
// plugin.Serve fully manages listeners to expose an RPC server from a binary
// that plugin.Client can connect to.
package plugin
import (
"errors"
"net/rpc"
"google.golang.org/grpc"
)
// Plugin is the interface that is implemented to serve/connect to an
// inteface implementation.
type Plugin interface {
// Server should return the RPC server compatible struct to serve
// the methods that the Client calls over net/rpc.
Server(*MuxBroker) (interface{}, error)
// Client returns an interface implementation for the plugin you're
// serving that communicates to the server end of the plugin.
Client(*MuxBroker, *rpc.Client) (interface{}, error)
}
// GRPCPlugin is the interface that is implemented to serve/connect to
// a plugin over gRPC.
type GRPCPlugin interface {
// GRPCServer should register this plugin for serving with the
// given GRPCServer. Unlike Plugin.Server, this is only called once
// since gRPC plugins serve singletons.
GRPCServer(*grpc.Server) error
// GRPCClient should return the interface implementation for the plugin
// you're serving via gRPC.
GRPCClient(*grpc.ClientConn) (interface{}, error)
}
// NetRPCUnsupportedPlugin implements Plugin but returns errors for the
// Server and Client functions. This will effectively disable support for
// net/rpc based plugins.
//
// This struct can be embedded in your struct.
type NetRPCUnsupportedPlugin struct{}
func (p NetRPCUnsupportedPlugin) Server(*MuxBroker) (interface{}, error) {
return nil, errors.New("net/rpc plugin protocol not supported")
}
func (p NetRPCUnsupportedPlugin) Client(*MuxBroker, *rpc.Client) (interface{}, error) {
return nil, errors.New("net/rpc plugin protocol not supported")
}