refactor: plugin functions can be defined in any format

plugin/examples/debugtalk.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"fmt"
+
+	plugin "github.com/httprunner/hrp/plugin"
+)
+
+func SumTwoInt(a, b int) int {
+	return a + b
+}
+
+func SumInts(args ...int) int {
+	var sum int
+	for _, arg := range args {
+		sum += arg
+	}
+	return sum
+}
+
+func Sum(args ...interface{}) (interface{}, error) {
+	var sum float64
+	for _, arg := range args {
+		switch v := arg.(type) {
+		case int:
+			sum += float64(v)
+		case float64:
+			sum += v
+		default:
+			return nil, fmt.Errorf("unexpected type: %T", arg)
+		}
+	}
+	return sum, nil
+}
+
+func SumTwoString(a, b string) string {
+	return a + b
+}
+
+func SumStrings(s ...string) string {
+	var sum string
+	for _, arg := range s {
+		sum += arg
+	}
+	return sum
+}
+
+func Concatenate(args ...interface{}) (interface{}, error) {
+	var result string
+	for _, arg := range args {
+		result += fmt.Sprintf("%v", arg)
+	}
+	return result, nil
+}
+
+// register functions and build to plugin binary
+func main() {
+	plugin.Register("sum_ints", SumInts)
+	plugin.Register("sum_two_int", SumTwoInt)
+	plugin.Register("sum", Sum)
+	plugin.Register("sum_two_string", SumTwoString)
+	plugin.Register("sum_strings", SumStrings)
+	plugin.Register("concatenate", Concatenate)
+	plugin.Serve()
+}

plugin/examples/plugin_test.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/httprunner/hrp/plugin/host"
+)
+
+func TestMain(m *testing.M) {
+	fmt.Println("[TestMain] build go plugin")
+	cmd := exec.Command("go", "build", "-o=debugtalk.bin", "./debugtalk.go")
+	if err := cmd.Run(); err != nil {
+		panic(err)
+	}
+	os.Exit(m.Run())
+}
+
+func TestInitHashicorpPlugin(t *testing.T) {
+	f, err := host.Init("./debugtalk.bin")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer host.Quit()
+
+	v1, err := f.GetNames()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !assert.Contains(t, v1, "sum_ints") {
+		t.Fatal(err)
+	}
+	if !assert.Contains(t, v1, "concatenate") {
+		t.Fatal(err)
+	}
+
+	var v2 interface{}
+	v2, err = f.Call("sum_ints", 1, 2, 3, 4)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !assert.Equal(t, 10, v2) {
+		t.Fail()
+	}
+	v2, err = f.Call("sum_two_int", 1, 2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !assert.Equal(t, 3, v2) {
+		t.Fail()
+	}
+	v2, err = f.Call("sum", 1, 2, 3.4, 5)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !assert.Equal(t, 11.4, v2) {
+		t.Fail()
+	}
+
+	var v3 interface{}
+	v3, err = f.Call("sum_two_string", "a", "b")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !assert.Equal(t, "ab", v3) {
+		t.Fail()
+	}
+	v3, err = f.Call("sum_strings", "a", "b", "c")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !assert.Equal(t, "abc", v3) {
+		t.Fail()
+	}
+
+	v3, err = f.Call("concatenate", "a", 2, "c", 3.4)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !assert.Equal(t, "a2c3.4", v3) {
+		t.Fail()
+	}
+}

plugin/host/host.go

@@ -0,0 +1,50 @@
+package host
+
+import (
+	"os"
+	"os/exec"
+
+	hclog "github.com/hashicorp/go-hclog"
+	"github.com/hashicorp/go-plugin"
+
+	"github.com/httprunner/hrp/plugin/shared"
+)
+
+var client *plugin.Client
+
+func Init(path string) (shared.FuncCaller, error) {
+	// launch the plugin process
+	client = plugin.NewClient(&plugin.ClientConfig{
+		HandshakeConfig: shared.HandshakeConfig,
+		Plugins: map[string]plugin.Plugin{
+			shared.Name: &shared.HashicorpPlugin{},
+		},
+		Cmd: exec.Command(path),
+		Logger: hclog.New(&hclog.LoggerOptions{
+			Name:   shared.Name,
+			Output: os.Stdout,
+			Level:  hclog.Info,
+		}),
+	})
+
+	// Connect via RPC
+	rpcClient, err := client.Client()
+	if err != nil {
+		return nil, err
+	}
+
+	// Request the plugin
+	raw, err := rpcClient.Dispense(shared.Name)
+	if err != nil {
+		return nil, err
+	}
+
+	// We should have a Function now! This feels like a normal interface
+	// implementation but is in fact over an RPC connection.
+	function := raw.(shared.FuncCaller)
+	return function, nil
+}
+
+func Quit() {
+	client.Kill()
+}

plugin/plugin.go

@@ -0,0 +1,67 @@
+package plugin
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+
+	hclog "github.com/hashicorp/go-hclog"
+	"github.com/hashicorp/go-plugin"
+
+	pluginShared "github.com/httprunner/hrp/plugin/shared"
+)
+
+// functionsMap stores plugin functions
+type functionsMap map[string]reflect.Value
+
+// functionPlugin implements the FuncCaller interface
+type functionPlugin struct {
+	logger    hclog.Logger
+	functions functionsMap
+}
+
+func (p *functionPlugin) GetNames() ([]string, error) {
+	var names []string
+	for name := range p.functions {
+		names = append(names, name)
+	}
+	return names, nil
+}
+
+func (p *functionPlugin) Call(funcName string, args ...interface{}) (interface{}, error) {
+	p.logger.Info("call function", "funcName", funcName, "args", args)
+
+	fn, ok := p.functions[funcName]
+	if !ok {
+		return nil, fmt.Errorf("function %s not found", funcName)
+	}
+
+	return pluginShared.CallFunc(fn, args...)
+}
+
+var functions = make(functionsMap)
+
+func Register(funcName string, fn interface{}) {
+	if _, ok := functions[funcName]; ok {
+		return
+	}
+	functions[funcName] = reflect.ValueOf(fn)
+}
+
+func Serve() {
+	funcPlugin := &functionPlugin{
+		logger: hclog.New(&hclog.LoggerOptions{
+			Name:   pluginShared.Name,
+			Output: os.Stdout,
+			Level:  hclog.Info,
+		}),
+		functions: functions,
+	}
+	var pluginMap = map[string]plugin.Plugin{
+		pluginShared.Name: &pluginShared.HashicorpPlugin{Impl: funcPlugin},
+	}
+	plugin.Serve(&plugin.ServeConfig{
+		HandshakeConfig: pluginShared.HandshakeConfig,
+		Plugins:         pluginMap,
+	})
+}

plugin/shared/config.go

@@ -0,0 +1,15 @@
+package shared
+
+import "github.com/hashicorp/go-plugin"
+
+const Name = "debugtalk"
+
+// handshakeConfigs are used to just do a basic handshake between
+// a plugin and host. If the handshake fails, a user friendly error is shown.
+// This prevents users from executing bad plugins or executing a plugin
+// directory. It is a UX feature, not a security feature.
+var HandshakeConfig = plugin.HandshakeConfig{
+	ProtocolVersion:  1,
+	MagicCookieKey:   "HttpRunnerPlus",
+	MagicCookieValue: Name,
+}

plugin/shared/interface.go

@@ -0,0 +1,103 @@
+package shared
+
+import (
+	"encoding/gob"
+	"net/rpc"
+
+	"github.com/hashicorp/go-plugin"
+	"github.com/rs/zerolog/log"
+)
+
+func init() {
+	gob.Register(new(funcData))
+}
+
+// funcData is used to transfer between plugin and host via RPC.
+type funcData struct {
+	Name string        // function name
+	Args []interface{} // function arguments
+}
+
+// FuncCaller is the interface that we're exposing as a plugin.
+type FuncCaller interface {
+	GetNames() ([]string, error)                                    // get all plugin function names list
+	Call(funcName string, args ...interface{}) (interface{}, error) // call plugin function
+}
+
+// functionRPC runs on the host side.
+type functionRPC struct {
+	client *rpc.Client
+}
+
+func (g *functionRPC) GetNames() ([]string, error) {
+	var resp []string
+	err := g.client.Call("Plugin.GetNames", new(interface{}), &resp)
+	if err != nil {
+		log.Error().Err(err).Msg("rpc call GetNames() failed")
+		return nil, err
+	}
+	return resp, nil
+}
+
+// host -> plugin
+func (g *functionRPC) Call(funcName string, funcArgs ...interface{}) (interface{}, error) {
+	log.Info().Str("funcName", funcName).Interface("funcArgs", funcArgs).Msg("call function via RPC")
+	f := funcData{
+		Name: funcName,
+		Args: funcArgs,
+	}
+
+	var args interface{} = f
+	var resp interface{}
+	err := g.client.Call("Plugin.Call", &args, &resp)
+	if err != nil {
+		log.Error().Err(err).
+			Str("funcName", funcName).Interface("funcArgs", funcArgs).
+			Msg("rpc call Call() failed")
+		return nil, err
+	}
+	return resp, nil
+}
+
+// functionRPCServer runs on the plugin side, executing the user custom function.
+type functionRPCServer struct {
+	Impl FuncCaller
+}
+
+// plugin execution
+func (s *functionRPCServer) GetNames(args interface{}, resp *[]string) error {
+	log.Info().Interface("args", args).Msg("GetNames called on plugin side")
+	var err error
+	*resp, err = s.Impl.GetNames()
+	if err != nil {
+		log.Error().Err(err).Msg("GetNames execution failed")
+		return err
+	}
+	return nil
+}
+
+// plugin execution
+func (s *functionRPCServer) Call(args interface{}, resp *interface{}) error {
+	log.Info().Interface("args", args).Msg("function called on plugin side")
+	f := args.(*funcData)
+	var err error
+	*resp, err = s.Impl.Call(f.Name, f.Args...)
+	if err != nil {
+		log.Error().Err(err).Interface("args", args).Msg("function execution failed")
+		return err
+	}
+	return nil
+}
+
+// HashicorpPlugin implements hashicorp's plugin.Plugin.
+type HashicorpPlugin struct {
+	Impl FuncCaller
+}
+
+func (p *HashicorpPlugin) Server(*plugin.MuxBroker) (interface{}, error) {
+	return &functionRPCServer{Impl: p.Impl}, nil
+}
+
+func (HashicorpPlugin) Client(b *plugin.MuxBroker, c *rpc.Client) (interface{}, error) {
+	return &functionRPC{client: c}, nil
+}

plugin/shared/utils.go

@@ -0,0 +1,50 @@
+package shared
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// CallFunc calls function with arguments
+// it is used when calling go plugin or builtin functions
+func CallFunc(fn reflect.Value, args ...interface{}) (interface{}, error) {
+	fnArgsNum := fn.Type().NumIn()
+	if fnArgsNum > 0 && fn.Type().In(fnArgsNum-1).Kind() == reflect.Slice {
+		// last argument is slice, do not check arguments number
+		// e.g. ...interface{}
+		// e.g. a, b string, c ...interface{}
+	} else if fnArgsNum != len(args) {
+		// function arguments not match
+		return nil, fmt.Errorf("function arguments number not match, expect %d, got %d", fnArgsNum, len(args))
+	}
+	// arguments do not have slice, and arguments number matched
+
+	argumentsValue := make([]reflect.Value, len(args))
+	for index, argument := range args {
+		if argument == nil {
+			argumentsValue[index] = reflect.Zero(fn.Type().In(index))
+		} else {
+			argumentsValue[index] = reflect.ValueOf(args[index])
+		}
+	}
+
+	resultValues := fn.Call(argumentsValue)
+	if resultValues == nil {
+		// no returns
+		return nil, nil
+	} else if len(resultValues) == 2 {
+		// return two arguments: interface{}, error
+		if resultValues[1].Interface() != nil {
+			return resultValues[0].Interface(), resultValues[1].Interface().(error)
+		} else {
+			return resultValues[0].Interface(), nil
+		}
+	} else if len(resultValues) == 1 {
+		// return one arguments: interface{}
+		return resultValues[0].Interface(), nil
+	} else {
+		// return more than 2 arguments, unexpected
+		err := fmt.Errorf("function should return at most 2 arguments")
+		return nil, err
+	}
+}