WIP: extension feature

example/extendable/Makefile

@@ -2,7 +2,7 @@ build: extension
 	go build -o ./bin/app ./
 
 extension:
-	go build  -o ./bin/myplugin.so -buildmode=plugin ./myplugin
+	go build  -o ./bin/myext.so -buildmode=plugin ./myext
 
 watch:
 	modd

example/extendable/main.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"context"
+	"log"
+
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/extension"
+)
+
+func main() {
+	reg := extension.NewRegistry()
+	ctx := context.Background()
+
+	extensions, err := reg.LoadAll(ctx, "./bin/*.so")
+	if err != nil {
+		log.Fatal(errors.WithStack(err))
+	}
+
+	for _, ext := range extensions {
+		log.Printf("Loaded extension '%s', version '%s'", ext.ExtensionName(), ext.ExtensionVersion())
+	}
+}

example/extendable/myext/extension.go

@@ -0,0 +1,12 @@
+package main
+
+type MyExtension struct {
+}
+
+func (e *MyExtension) ExtensionName() string {
+	return "my.extension"
+}
+
+func (e *MyExtension) ExtensionVersion() string {
+	return "0.0.0"
+}

example/extendable/myext/main.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"context"
+
+	"gitlab.com/wpetit/goweb/extension"
+)
+
+func RegisterExtension(ctx context.Context) (extension.Extension, error) {
+	return &MyExtension{}, nil
+}

example/pluggable/hook/initializable.go

@@ -1,5 +0,0 @@
-package hook
-
-type Initializable interface {
-	HookInit() error
-}

example/pluggable/main.go

@@ -1,44 +0,0 @@
-package main
-
-import (
-	"context"
-	"log"
-
-	"github.com/pkg/errors"
-	"gitlab.com/wpetit/goweb/example/pluggable/hook"
-	"gitlab.com/wpetit/goweb/plugin"
-)
-
-func main() {
-	reg := plugin.NewRegistry()
-	ctx := context.Background()
-
-	_, err := reg.LoadAll(ctx, "./bin/*.so")
-	if err != nil {
-		log.Fatal(errors.WithStack(err))
-	}
-
-	for _, ext := range reg.Plugins() {
-		log.Printf("Loaded plugin '%s', version '%s'", ext.PluginName(), ext.PluginVersion())
-	}
-
-	// Iterate over plugins
-	err = reg.Each(func(p plugin.Plugin) error {
-		h, ok := p.(hook.Initializable)
-		if !ok {
-			// Skip non initializable plugins
-			return nil
-		}
-
-		// Initialize plugin
-		if err := h.HookInit(); err != nil {
-			return errors.WithStack(err)
-		}
-
-		return nil
-	})
-
-	if err != nil {
-		log.Fatal(errors.WithStack(err))
-	}
-}

example/pluggable/myplugin/main.go

@@ -1,11 +0,0 @@
-package main
-
-import (
-	"context"
-
-	"gitlab.com/wpetit/goweb/plugin"
-)
-
-func RegisterPlugin(ctx context.Context) (plugin.Plugin, error) {
-	return &MyPlugin{}, nil
-}

example/pluggable/myplugin/plugin.go

@@ -1,19 +0,0 @@
-package main
-
-import "log"
-
-type MyPlugin struct{}
-
-func (e *MyPlugin) PluginName() string {
-	return "my.plugin"
-}
-
-func (e *MyPlugin) PluginVersion() string {
-	return "0.0.0"
-}
-
-func (e *MyPlugin) HookInit() error {
-	log.Println("MyPlugin initialized !")
-
-	return nil
-}

extension/error.go

@@ -0,0 +1,8 @@
+package extension
+
+import "errors"
+
+var (
+	ErrInvalidRegisterFunc = errors.New("invalid register func")
+	ErrInvalidExtension    = errors.New("invalid extension")
+)

extension/extension.go

@@ -0,0 +1,6 @@
+package extension
+
+type Extension interface {
+	ExtensionName() string
+	ExtensionVersion() string
+}

extension/registry.go

@@ -0,0 +1,101 @@
+package extension
+
+import (
+	"context"
+	"path/filepath"
+	"plugin"
+	"sync"
+
+	"github.com/pkg/errors"
+)
+
+type Registry struct {
+	extensions map[string]Extension
+	mutex      sync.RWMutex
+}
+
+func (r *Registry) Load(ctx context.Context, path string) (Extension, error) {
+	p, err := plugin.Open(path)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	registerFuncSymbol, err := p.Lookup("RegisterExtension")
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	register, ok := registerFuncSymbol.(func(context.Context) (Extension, error))
+	if !ok {
+		return nil, errors.WithStack(ErrInvalidRegisterFunc)
+	}
+
+	ext, err := register(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	if ext == nil {
+		return nil, errors.WithStack(ErrInvalidExtension)
+	}
+
+	r.mutex.Lock()
+	r.extensions[ext.ExtensionName()] = ext
+	r.mutex.Unlock()
+
+	return ext, nil
+}
+
+func (r *Registry) LoadAll(ctx context.Context, pattern string) ([]Extension, error) {
+	extensions := make([]Extension, 0)
+
+	matches, err := filepath.Glob(pattern)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	for _, m := range matches {
+		ext, err := r.Load(ctx, m)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		extensions = append(extensions, ext)
+	}
+
+	return extensions, nil
+}
+
+func (r *Registry) Extensions() []Extension {
+	r.mutex.RLock()
+	defer r.mutex.RUnlock()
+
+	extensions := make([]Extension, 0, len(r.extensions))
+	for _, e := range r.extensions {
+		extensions = append(extensions, e)
+	}
+
+	return extensions
+}
+
+type ExtensionFilterFunc func(ext Extension) bool
+
+func (r *Registry) Filter(filter ExtensionFilterFunc) []Extension {
+	r.mutex.RLock()
+	defer r.mutex.RUnlock()
+
+	extensions := make([]Extension, 0, len(r.extensions))
+	for _, e := range r.extensions {
+		if filter(e) {
+			extensions = append(extensions, e)
+		}
+	}
+
+	return extensions
+}
+
+func NewRegistry() *Registry {
+	return &Registry{
+		extensions: make(map[string]Extension),
+	}
+}

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/gorilla/sessions v1.2.0
 	github.com/leodido/go-urn v1.1.0 // indirect
 	github.com/oxtoacart/bpool v0.0.0-20190530202638-03653db5a59c
-	github.com/pkg/errors v0.9.1
+	github.com/pkg/errors v0.8.1
 	gopkg.in/go-playground/assert.v1 v1.2.1 // indirect
 	gopkg.in/go-playground/validator.v9 v9.29.1
 )

go.sum

@@ -104,8 +104,6 @@ github.com/oxtoacart/bpool v0.0.0-20190530202638-03653db5a59c/go.mod h1:X07ZCGwU
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
-github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=

plugin/error.go

@@ -1,16 +0,0 @@
-package plugin
-
-import "errors"
-
-var (
-	// ErrInvalidRegisterFunc is returned when the plugin package
-	// could not find the expected RegisterPlugin func in the loaded
-	// plugin.
-	ErrInvalidRegisterFunc = errors.New("invalid register func")
-	// ErrInvalidPlugin is returned when a loaded plugin does
-	// not match the expected interface.
-	ErrInvalidPlugin = errors.New("invalid plugin")
-	// ErrPluginNotFound is returned when the given plugin could
-	// not be found in the registry.
-	ErrPluginNotFound = errors.New("plugin not found")
-)

plugin/plugin.go

@@ -1,6 +0,0 @@
-package plugin
-
-type Plugin interface {
-	PluginName() string
-	PluginVersion() string
-}

plugin/registry.go

@@ -1,117 +0,0 @@
-package plugin
-
-import (
-	"context"
-	"path/filepath"
-	"plugin"
-	"sync"
-
-	"github.com/pkg/errors"
-)
-
-type Registry struct {
-	plugins map[string]Plugin
-	mutex   sync.RWMutex
-}
-
-func (r *Registry) Add(plg Plugin) {
-	r.mutex.Lock()
-	defer r.mutex.Unlock()
-
-	r.plugins[plg.PluginName()] = plg
-}
-
-func (r *Registry) Get(name string) (Plugin, error) {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
-
-	plg, exists := r.plugins[name]
-	if !exists {
-		return nil, errors.WithStack(ErrPluginNotFound)
-	}
-
-	return plg, nil
-}
-
-func (r *Registry) Load(ctx context.Context, path string) (Plugin, error) {
-	p, err := plugin.Open(path)
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
-	registerFuncSymbol, err := p.Lookup("RegisterPlugin")
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
-	register, ok := registerFuncSymbol.(func(context.Context) (Plugin, error))
-	if !ok {
-		return nil, errors.WithStack(ErrInvalidRegisterFunc)
-	}
-
-	plg, err := register(ctx)
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
-	if plg == nil {
-		return nil, errors.WithStack(ErrInvalidPlugin)
-	}
-
-	r.Add(plg)
-
-	return plg, nil
-}
-
-func (r *Registry) LoadAll(ctx context.Context, pattern string) ([]Plugin, error) {
-	extensions := make([]Plugin, 0)
-
-	matches, err := filepath.Glob(pattern)
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
-	for _, m := range matches {
-		ext, err := r.Load(ctx, m)
-		if err != nil {
-			return nil, errors.WithStack(err)
-		}
-
-		extensions = append(extensions, ext)
-	}
-
-	return extensions, nil
-}
-
-func (r *Registry) Plugins() []Plugin {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
-
-	plugins := make([]Plugin, 0, len(r.plugins))
-	for _, p := range r.plugins {
-		plugins = append(plugins, p)
-	}
-
-	return plugins
-}
-
-type IteratorFunc func(plg Plugin) error
-
-func (r *Registry) Each(iterator IteratorFunc) error {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
-
-	for _, p := range r.plugins {
-		if err := iterator(p); err != nil {
-			return errors.WithStack(err)
-		}
-	}
-
-	return nil
-}
-
-func NewRegistry() *Registry {
-	return &Registry{
-		plugins: make(map[string]Plugin),
-	}
-}

plugin/registry_test.go

@@ -1,94 +0,0 @@
-package plugin_test
-
-import (
-	"testing"
-
-	"github.com/pkg/errors"
-	"gitlab.com/wpetit/goweb/plugin"
-)
-
-type testPlugin struct {
-	name    string
-	version string
-}
-
-func (p *testPlugin) PluginName() string {
-	return p.name
-}
-
-func (p *testPlugin) PluginVersion() string {
-	return p.version
-}
-
-func (p *testPlugin) Foo() string {
-	return "bar"
-}
-
-func TestRegistryEach(t *testing.T) {
-	t.Parallel()
-
-	reg := plugin.NewRegistry()
-
-	plugins := []*testPlugin{
-		{"plugin.a", "0.0.0"},
-		{"plugin.b", "0.0.1"},
-	}
-
-	for _, p := range plugins {
-		reg.Add(p)
-	}
-
-	total := 0
-
-	err := reg.Each(func(p plugin.Plugin) error {
-		total++
-
-		return nil
-	})
-	if err != nil {
-		t.Error(errors.WithStack(err))
-	}
-
-	if e, g := len(plugins), total; e != g {
-		t.Errorf("total: expected '%v', got '%v'", e, g)
-	}
-}
-
-func TestRegistryGet(t *testing.T) {
-	t.Parallel()
-
-	reg := plugin.NewRegistry()
-
-	plugins := []*testPlugin{
-		{"plugin.a", "0.0.0"},
-		{"plugin.b", "0.0.1"},
-	}
-
-	for _, p := range plugins {
-		reg.Add(p)
-	}
-
-	for _, p := range plugins {
-		plugin, err := reg.Get(p.name)
-		if err != nil {
-			t.Error(errors.WithStack(err))
-		}
-
-		if e, g := p.name, plugin.PluginName(); e != g {
-			t.Errorf("plugin.PluginName(): expected '%v', got '%v'", e, g)
-		}
-
-		if e, g := p.version, plugin.PluginVersion(); e != g {
-			t.Errorf("plugin.PluginVersion(): expected '%v', got '%v'", e, g)
-		}
-	}
-
-	p, err := reg.Get("plugin.c")
-	if !errors.Is(err, plugin.ErrPluginNotFound) {
-		t.Errorf("err: expected '%v', got '%v'", plugin.ErrPluginNotFound, err)
-	}
-
-	if p != nil {
-		t.Errorf("reg.Get(\"plugin.c\"): expected '%v', got '%v'", nil, p)
-	}
-}