1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
package example
import (
"net/rpc"
"github.com/hashicorp/go-plugin"
)
// Greeter is the interface that we're exposing as a plugin.
type Greeter interface {
Greet() string
}
// Here is an implementation that talks over RPC
type GreeterRPC struct{ client *rpc.Client }
func (g *GreeterRPC) Greet() string {
var resp string
err := g.client.Call("Plugin.Greet", new(interface{}), &resp)
if err != nil {
// You usually want your interfaces to return errors. If they don't,
// there isn't much other choice here.
panic(err)
}
return resp
}
// Here is the RPC server that GreeterRPC talks to, conforming to
// the requirements of net/rpc
type GreeterRPCServer struct {
// This is the real implementation
Impl Greeter
}
func (s *GreeterRPCServer) Greet(args interface{}, resp *string) error {
*resp = s.Impl.Greet()
return nil
}
// This is the implementation of plugin.Plugin so we can serve/consume this
//
// This has two methods: Server must return an RPC server for this plugin
// type. We construct a GreeterRPCServer for this.
//
// Client must return an implementation of our interface that communicates
// over an RPC client. We return GreeterRPC for this.
//
// Ignore MuxBroker. That is used to create more multiplexed streams on our
// plugin connection and is a more advanced use case.
type GreeterPlugin struct {
// Impl Injection
Impl Greeter
}
func (p *GreeterPlugin) Server(*plugin.MuxBroker) (interface{}, error) {
return &GreeterRPCServer{Impl: p.Impl}, nil
}
func (GreeterPlugin) Client(b *plugin.MuxBroker, c *rpc.Client) (interface{}, error) {
return &GreeterRPC{client: c}, nil
}
|
