add experimental plugin system

sdk/plugin/notifier.go

@@ -0,0 +1,135 @@
+package plugin
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"os/exec"
+
+	"github.com/hashicorp/go-hclog"
+	"github.com/hashicorp/go-plugin"
+
+	"github.com/drakkan/sftpgo/v2/logger"
+	"github.com/drakkan/sftpgo/v2/sdk/plugin/notifier"
+	"github.com/drakkan/sftpgo/v2/util"
+)
+
+// NotifierConfig defines configuration parameters for notifiers plugins
+type NotifierConfig struct {
+	FsEvents   []string `json:"fs_events" mapstructure:"fs_events"`
+	UserEvents []string `json:"user_events" mapstructure:"user_events"`
+}
+
+func (c *NotifierConfig) hasActions() bool {
+	if len(c.FsEvents) > 0 {
+		return true
+	}
+	if len(c.UserEvents) > 0 {
+		return true
+	}
+	return false
+}
+
+type notifierPlugin struct {
+	config   Config
+	notifier notifier.Notifier
+	client   *plugin.Client
+}
+
+func newNotifierPlugin(config Config) (*notifierPlugin, error) {
+	p := &notifierPlugin{
+		config: config,
+	}
+	if err := p.initialize(); err != nil {
+		logger.Warn(logSender, "", "unable to create notifier plugin: %v, config %v", err, config)
+		return nil, err
+	}
+	return p, nil
+}
+
+func (p *notifierPlugin) exited() bool {
+	return p.client.Exited()
+}
+
+func (p *notifierPlugin) cleanup() {
+	p.client.Kill()
+}
+
+func (p *notifierPlugin) initialize() error {
+	killProcess(p.config.Cmd)
+	logger.Debug(logSender, "", "create new plugin %v", p.config.Cmd)
+	if !p.config.NotifierOptions.hasActions() {
+		return fmt.Errorf("no actions defined for the notifier plugin %v", p.config.Cmd)
+	}
+	var secureConfig *plugin.SecureConfig
+	if p.config.SHA256Sum != "" {
+		secureConfig.Checksum = []byte(p.config.SHA256Sum)
+		secureConfig.Hash = sha256.New()
+	}
+	client := plugin.NewClient(&plugin.ClientConfig{
+		HandshakeConfig: notifier.Handshake,
+		Plugins:         notifier.PluginMap,
+		Cmd:             exec.Command(p.config.Cmd, p.config.Args...),
+		AllowedProtocols: []plugin.Protocol{
+			plugin.ProtocolGRPC,
+		},
+		AutoMTLS:     p.config.AutoMTLS,
+		SecureConfig: secureConfig,
+		Managed:      false,
+		Logger: &logger.HCLogAdapter{
+			Logger: hclog.New(&hclog.LoggerOptions{
+				Name:        fmt.Sprintf("%v.%v", logSender, notifier.PluginName),
+				Level:       pluginsLogLevel,
+				DisableTime: true,
+			}),
+		},
+	})
+	rpcClient, err := client.Client()
+	if err != nil {
+		logger.Debug(logSender, "", "unable to get rpc client for plugin %v: %v", p.config.Cmd, err)
+		return err
+	}
+	raw, err := rpcClient.Dispense(notifier.PluginName)
+	if err != nil {
+		logger.Debug(logSender, "", "unable to get plugin %v from rpc client for plugin %v: %v",
+			notifier.PluginName, p.config.Cmd, err)
+		return err
+	}
+
+	p.client = client
+	p.notifier = raw.(notifier.Notifier)
+
+	return nil
+}
+
+func (p *notifierPlugin) notifyFsAction(action, username, fsPath, fsTargetPath, sshCmd, protocol string, fileSize int64, errAction error) {
+	if !util.IsStringInSlice(action, p.config.NotifierOptions.FsEvents) {
+		return
+	}
+
+	go func() {
+		status := 1
+		if errAction != nil {
+			status = 0
+		}
+		if err := p.notifier.NotifyFsEvent(action, username, fsPath, fsTargetPath, sshCmd, protocol, fileSize, status); err != nil {
+			logger.Warn(logSender, "", "unable to send fs action notification to plugin %v: %v", p.config.Cmd, err)
+		}
+	}()
+}
+
+func (p *notifierPlugin) notifyUserAction(action string, user Renderer) {
+	if !util.IsStringInSlice(action, p.config.NotifierOptions.UserEvents) {
+		return
+	}
+
+	go func() {
+		userAsJSON, err := user.RenderAsJSON(action != "delete")
+		if err != nil {
+			logger.Warn(logSender, "", "unable to render user as json for action %v: %v", action, err)
+			return
+		}
+		if err := p.notifier.NotifyUserEvent(action, userAsJSON); err != nil {
+			logger.Warn(logSender, "", "unable to send user action notification to plugin %v: %v", p.config.Cmd, err)
+		}
+	}()
+}