feat(plugins): add rudimentary plugin system

.gitignore

@@ -29,6 +29,7 @@ os-packages/
 mage_output_file.go
 mage-static
 .DS_Store
+/plugins/*
 
 # Devenv
 .devenv*
@@ -44,3 +45,4 @@ devenv.local.nix
 /.claude/
 PLAN.md
 /.crush/
+

examples/plugins/example/main.go

@@ -0,0 +1,52 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"code.vikunja.io/api/pkg/events"
+	"code.vikunja.io/api/pkg/log"
+	"code.vikunja.io/api/pkg/models"
+	"code.vikunja.io/api/pkg/plugins"
+
+	"github.com/ThreeDotsLabs/watermill/message"
+)
+
+type ExamplePlugin struct{}
+
+func (p *ExamplePlugin) Name() string    { return "example" }
+func (p *ExamplePlugin) Version() string { return "1.0.0" }
+func (p *ExamplePlugin) Init() error {
+	log.Infof("example plugin initialized")
+
+	events.RegisterListener((&models.TaskCreatedEvent{}).Name(), &TestListener{})
+
+	return nil
+}
+func (p *ExamplePlugin) Shutdown() error { return nil }
+
+func NewPlugin() plugins.Plugin { return &ExamplePlugin{} }
+
+type TestListener struct{}
+
+func (t *TestListener) Handle(msg *message.Message) error {
+	log.Infof("TestListener received message: %s", string(msg.Payload))
+	return nil
+}
+
+func (t *TestListener) Name() string {
+	return "TestListener"
+}

magefile.go

@@ -73,6 +73,7 @@ var (
 		"dev:make-event":              Dev.MakeEvent,
 		"dev:make-listener":           Dev.MakeListener,
 		"dev:make-notification":       Dev.MakeNotification,
+		"plugins:build":               Plugins.Build,
 		"lint":                        Check.Golangci,
 		"lint:fix":                    Check.GolangciFix,
 		"generate:config-yaml":        Generate.ConfigYAML,
@@ -1393,3 +1394,26 @@ func generateConfigYAMLFromJSON(yamlPath string, commented bool) {
 func (Generate) ConfigYAML(commented bool) {
 	generateConfigYAMLFromJSON(DefaultConfigYAMLSamplePath, commented)
 }
+
+type Plugins mg.Namespace
+
+// Build compiles a Go plugin at the provided path.
+func (Plugins) Build(pathToSourceFiles string) error {
+	mg.Deps(initVars)
+	if pathToSourceFiles == "" {
+		return fmt.Errorf("please provide a plugin path")
+	}
+	
+	// Convert relative path to absolute path
+	if !strings.HasPrefix(pathToSourceFiles, "/") {
+		absPath, err := filepath.Abs(pathToSourceFiles)
+		if err != nil {
+			return fmt.Errorf("failed to resolve absolute path: %v", err)
+		}
+		pathToSourceFiles = absPath
+	}
+	
+	out := filepath.Join(RootPath, "plugins", filepath.Base(pathToSourceFiles)+".so")
+	runAndStreamOutput("go", "build", "-buildmode=plugin", "-o", out, pathToSourceFiles)
+	return nil
+}

pkg/cmd/web.go

@@ -30,6 +30,7 @@ import (
 	"code.vikunja.io/api/pkg/cron"
 	"code.vikunja.io/api/pkg/initialize"
 	"code.vikunja.io/api/pkg/log"
+	"code.vikunja.io/api/pkg/plugins"
 	"code.vikunja.io/api/pkg/routes"
 	"code.vikunja.io/api/pkg/utils"
 	"code.vikunja.io/api/pkg/version"
@@ -160,5 +161,6 @@ var webCmd = &cobra.Command{
 			e.Logger.Fatal(err)
 		}
 		cron.Stop()
+		plugins.Shutdown()
 	},
 }

pkg/config/config.go

@@ -207,6 +207,9 @@ const (
 	AutoTLSEnabled     Key = `autotls.enabled`
 	AutoTLSEmail       Key = `autotls.email`
 	AutoTLSRenewBefore Key = `autotls.renewbefore`
+
+	PluginsEnabled Key = `plugins.enabled`
+	PluginsDir     Key = `plugins.dir`
 )
 
 // GetString returns a string config value
@@ -446,6 +449,9 @@ func InitDefaultConfig() {
 	WebhooksTimeoutSeconds.setDefault(30)
 	// AutoTLS
 	AutoTLSRenewBefore.setDefault("720h") // 30days in hours
+	// Plugins
+	PluginsEnabled.setDefault(false)
+	PluginsDir.setDefault(filepath.Join(ServiceRootpath.GetString(), "plugins"))
 }
 
 func GetConfigValueFromFile(configKey string) string {

pkg/initialize/init.go

@@ -33,6 +33,7 @@ import (
 	"code.vikunja.io/api/pkg/modules/auth/openid"
 	"code.vikunja.io/api/pkg/modules/keyvalue"
 	migrationHandler "code.vikunja.io/api/pkg/modules/migration/handler"
+	"code.vikunja.io/api/pkg/plugins"
 	"code.vikunja.io/api/pkg/red"
 	"code.vikunja.io/api/pkg/user"
 )
@@ -98,6 +99,9 @@ func FullInitWithoutAsync() {
 
 	// Load translations
 	i18n.Init()
+
+	// Initialize plugins
+	plugins.Initialize()
 }
 
 // FullInit initializes all kinds of things in the right order

pkg/migration/migration.go

@@ -39,6 +39,11 @@ import (
 
 var migrations []*xormigrate.Migration
 
+// AddPluginMigrations adds migrations provided by plugins to the global list.
+func AddPluginMigrations(ms []*xormigrate.Migration) {
+	migrations = append(migrations, ms...)
+}
+
 // A helper function because we need a migration in various places which we can't really solve with an init() function.
 func initMigration(x *xorm.Engine) *xormigrate.Xormigrate {
 	// Get our own xorm engine if we don't have one

pkg/plugins/interfaces.go

@@ -0,0 +1,35 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package plugins
+
+import (
+	"src.techknowlogick.com/xormigrate"
+)
+
+// Plugin is the base interface all plugins need to implement.
+type Plugin interface {
+	Name() string
+	Version() string
+	Init() error
+	Shutdown() error
+}
+
+// MigrationPlugin lets a plugin provide database migrations.
+type MigrationPlugin interface {
+	Plugin
+	Migrations() []*xormigrate.Migration
+}

pkg/plugins/manager.go

@@ -0,0 +1,119 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package plugins
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	goplugin "plugin"
+
+	"code.vikunja.io/api/pkg/config"
+	"code.vikunja.io/api/pkg/log"
+	"code.vikunja.io/api/pkg/migration"
+)
+
+// Manager handles loading and managing plugins.
+type Manager struct {
+	plugins        []Plugin
+	migrationPlugs []MigrationPlugin
+}
+
+var manager = &Manager{}
+
+// ManagerInstance returns the global plugin manager.
+func ManagerInstance() *Manager { return manager }
+
+// Initialize loads plugins and runs their migrations and init functions.
+func Initialize() {
+	if !config.PluginsEnabled.GetBool() {
+		return
+	}
+
+	paths := []string{config.PluginsDir.GetString()}
+	if err := manager.loadPlugins(paths); err != nil {
+		log.Fatalf("Loading plugins failed: %v", err)
+	}
+
+	// Run plugin migrations after core migrations
+	if len(manager.migrationPlugs) > 0 {
+		migration.Migrate(nil)
+	}
+
+	for _, p := range manager.plugins {
+		if err := p.Init(); err != nil {
+			log.Errorf("Plugin %s failed to init: %s", p.Name(), err)
+		}
+	}
+}
+
+// Shutdown calls Shutdown on all loaded plugins.
+func Shutdown() {
+	for _, p := range manager.plugins {
+		if err := p.Shutdown(); err != nil {
+			log.Errorf("Plugin %s shutdown failed: %s", p.Name(), err)
+		}
+	}
+}
+
+func (m *Manager) loadPlugins(paths []string) error {
+	for _, p := range paths {
+		entries, err := os.ReadDir(p)
+		if err != nil {
+			if errors.Is(err, os.ErrNotExist) {
+				continue
+			}
+			return err
+		}
+		for _, e := range entries {
+			if filepath.Ext(e.Name()) != ".so" {
+				continue
+			}
+			full := filepath.Join(p, e.Name())
+			if err := m.loadPlugin(full); err != nil {
+				log.Errorf("Failed to load plugin %s: %s", e.Name(), err)
+			}
+		}
+	}
+	return nil
+}
+
+func (m *Manager) loadPlugin(path string) error {
+	pl, err := goplugin.Open(path)
+	if err != nil {
+		return err
+	}
+	sym, err := pl.Lookup("NewPlugin")
+	if err != nil {
+		return err
+	}
+	newPlugin, ok := sym.(func() Plugin)
+	if !ok {
+		return errors.New("invalid plugin entry point")
+	}
+	p := newPlugin()
+	m.plugins = append(m.plugins, p)
+
+	if mp, ok := p.(MigrationPlugin); ok {
+		m.migrationPlugs = append(m.migrationPlugs, mp)
+		migration.AddPluginMigrations(mp.Migrations())
+	}
+
+	log.Infof("Loaded plugin %s", p.Name())
+
+	return nil
+}

pkg/plugins/registry.go

@@ -0,0 +1,48 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package plugins
+
+import "sync"
+
+// Registry keeps track of loaded plugins.
+type Registry struct {
+	mu      sync.RWMutex
+	plugins map[string]Plugin
+}
+
+// NewRegistry creates a new Registry.
+func NewRegistry() *Registry {
+	return &Registry{plugins: make(map[string]Plugin)}
+}
+
+// Add registers a plugin.
+func (r *Registry) Add(p Plugin) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	r.plugins[p.Name()] = p
+}
+
+// All returns all registered plugins.
+func (r *Registry) All() []Plugin {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	res := make([]Plugin, 0, len(r.plugins))
+	for _, p := range r.plugins {
+		res = append(res, p)
+	}
+	return res
+}