fix: made sure any tokens output in the logs are now censored (#143)

cmd/root.go

@@ -12,6 +12,7 @@ import (
 	"github.com/lindell/multi-gitter/internal/git/cmdgit"
 	"github.com/lindell/multi-gitter/internal/git/gogit"
 	"github.com/lindell/multi-gitter/internal/http"
+	internallog "github.com/lindell/multi-gitter/internal/log"
 	"github.com/lindell/multi-gitter/internal/multigitter"
 	"github.com/lindell/multi-gitter/internal/scm/gitea"
 	"github.com/lindell/multi-gitter/internal/scm/github"
@@ -200,19 +201,35 @@ func logFlagInit(cmd *cobra.Command, args []string) error {
 
 	// Parse and set the log format
 	strFormat, _ := cmd.Flags().GetString("log-format")
+
+	var formatter log.Formatter
 	switch strFormat {
 	case "text":
-		log.SetFormatter(&log.TextFormatter{})
+		formatter = &log.TextFormatter{}
 	case "json":
-		log.SetFormatter(&log.JSONFormatter{})
+		formatter = &log.JSONFormatter{}
 	case "json-pretty":
-		log.SetFormatter(&log.JSONFormatter{
+		formatter = &log.JSONFormatter{
 			PrettyPrint: true,
-		})
+		}
 	default:
 		return fmt.Errorf(`unknown log-format "%s"`, strFormat)
 	}
 
+	// Make sure sensitive data is censored before logging them
+	var censorItems []internallog.CensorItem
+	if token, err := getToken(cmd.Flags()); err == nil && token != "" {
+		censorItems = append(censorItems, internallog.CensorItem{
+			Sensitive:   token,
+			Replacement: "<TOKEN>",
+		})
+	}
+
+	log.SetFormatter(&internallog.CensorFormatter{
+		CensorItems:         censorItems,
+		UnderlyingFormatter: formatter,
+	})
+
 	// Set the output (file)
 	strFile, _ := cmd.Flags().GetString("log-file")
 	if strFile == "" {

internal/log/censor-formatter.go

@@ -0,0 +1,38 @@
+package log
+
+import (
+	"bytes"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// CensorFormatter makes sure sensitive data is not logged.
+// It works as a middleware and sensors the data before sending it to an underlying formatter
+type CensorFormatter struct {
+	CensorItems         []CensorItem
+	UnderlyingFormatter log.Formatter
+}
+
+// CensorItem is something that should be censored, Sensitive will be replaced with Replacement
+type CensorItem struct {
+	Sensitive   string
+	Replacement string
+}
+
+// Format censors some data and sends the entry to the underlying formatter
+func (f *CensorFormatter) Format(entry *log.Entry) ([]byte, error) {
+	for _, s := range f.CensorItems {
+		entry.Message = strings.ReplaceAll(entry.Message, s.Sensitive, s.Replacement)
+
+		for key := range entry.Data {
+			if str, ok := entry.Data[key].(string); ok {
+				entry.Data[key] = strings.ReplaceAll(str, s.Sensitive, s.Replacement)
+			}
+			if bb, ok := entry.Data[key].([]byte); ok {
+				entry.Data[key] = bytes.ReplaceAll(bb, []byte(s.Sensitive), []byte(s.Replacement))
+			}
+		}
+	}
+	return f.UnderlyingFormatter.Format(entry)
+}