refactor custom actions

SFTPGo is now fully auditable, all fs and provider events that change
something are notified and can be collected using hooks/plugins.

There are some backward incompatible changes for command hooks

dataprovider/actions.go

@@ -0,0 +1,105 @@
+package dataprovider
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/url"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/drakkan/sftpgo/v2/httpclient"
+	"github.com/drakkan/sftpgo/v2/logger"
+	"github.com/drakkan/sftpgo/v2/sdk/plugin"
+	"github.com/drakkan/sftpgo/v2/util"
+)
+
+const (
+	// ActionExecutorSelf is used as username for self action, for example a user/admin that updates itself
+	ActionExecutorSelf = "__self__"
+	// ActionExecutorSystem is used as username for actions with no explicit executor associated, for example
+	// adding/updating a user/admin by loading initial data
+	ActionExecutorSystem = "__system__"
+)
+
+const (
+	actionObjectUser   = "user"
+	actionObjectAdmin  = "admin"
+	actionObjectAPIKey = "api_key"
+)
+
+func executeAction(operation, executor, ip, objectType, objectName string, object plugin.Renderer) {
+	plugin.Handler.NotifyProviderEvent(time.Now(), operation, executor, objectType, objectName, ip, object)
+	if config.Actions.Hook == "" {
+		return
+	}
+	if !util.IsStringInSlice(operation, config.Actions.ExecuteOn) ||
+		!util.IsStringInSlice(objectType, config.Actions.ExecuteFor) {
+		return
+	}
+
+	go func() {
+		dataAsJSON, err := object.RenderAsJSON(operation != operationDelete)
+		if err != nil {
+			providerLog(logger.LevelWarn, "unable to serialize user as JSON for operation %#v: %v", operation, err)
+			return
+		}
+		if strings.HasPrefix(config.Actions.Hook, "http") {
+			var url *url.URL
+			url, err := url.Parse(config.Actions.Hook)
+			if err != nil {
+				providerLog(logger.LevelWarn, "Invalid http_notification_url %#v for operation %#v: %v", config.Actions.Hook, operation, err)
+				return
+			}
+			q := url.Query()
+			q.Add("action", operation)
+			q.Add("username", executor)
+			q.Add("ip", ip)
+			q.Add("object_type", objectType)
+			q.Add("object_name", objectName)
+			q.Add("timestamp", fmt.Sprintf("%v", util.GetTimeAsMsSinceEpoch(time.Now())))
+			url.RawQuery = q.Encode()
+			startTime := time.Now()
+			resp, err := httpclient.RetryablePost(url.String(), "application/json", bytes.NewBuffer(dataAsJSON))
+			respCode := 0
+			if err == nil {
+				respCode = resp.StatusCode
+				resp.Body.Close()
+			}
+			providerLog(logger.LevelDebug, "notified operation %#v to URL: %v status code: %v, elapsed: %v err: %v",
+				operation, url.Redacted(), respCode, time.Since(startTime), err)
+		} else {
+			executeNotificationCommand(operation, executor, ip, objectType, objectName, dataAsJSON) //nolint:errcheck // the error is used in test cases only
+		}
+	}()
+}
+
+func executeNotificationCommand(operation, executor, ip, objectType, objectName string, objectAsJSON []byte) error {
+	if !filepath.IsAbs(config.Actions.Hook) {
+		err := fmt.Errorf("invalid notification command %#v", config.Actions.Hook)
+		logger.Warn(logSender, "", "unable to execute notification command: %v", err)
+		return err
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, config.Actions.Hook)
+	cmd.Env = append(os.Environ(),
+		fmt.Sprintf("SFTPGO_PROVIDER_ACTION=%v", operation),
+		fmt.Sprintf("SFTPGO_PROVIDER_OBJECT_TYPE=%v", objectType),
+		fmt.Sprintf("SFTPGO_PROVIDER_OBJECT_NAME=%v", objectName),
+		fmt.Sprintf("SFTPGO_PROVIDER_USERNAME=%v", executor),
+		fmt.Sprintf("SFTPGO_PROVIDER_IP=%v", ip),
+		fmt.Sprintf("SFTPGO_PROVIDER_TIMESTAMP=%v", util.GetTimeAsMsSinceEpoch(time.Now())),
+		fmt.Sprintf("SFTPGO_PROVIDER_OBJECT=%v", string(objectAsJSON)))
+
+	startTime := time.Now()
+	err := cmd.Run()
+	providerLog(logger.LevelDebug, "executed command %#v, elapsed: %v, error: %v", config.Actions.Hook,
+		time.Since(startTime), err)
+	return err
+}