Add LogSanitizer interface, and ability to call it from ForceLog

pipeline/core.go

@@ -253,3 +253,22 @@ type methodFactoryMarker struct {
 func (methodFactoryMarker) New(next Policy, po *PolicyOptions) Policy {
 	panic("methodFactoryMarker policy should have been replaced with a method policy")
 }
+
+// LogSanitizer can be implemented to clean secrets from lines logged by ForceLog
+// By default no implemetation is provided here, because pipeline may be used in many different
+// contexts, so the correct implementation is context-dependent
+type LogSanitizer interface {
+	SanitizeLogLine(raw string) string
+}
+
+var sanitizer LogSanitizer
+
+// SetLogSanitizer can be called to supply a custom LogSanitizer.
+// There is no threadsafety or locking on the underlying variable,
+// so call this function just once at startup of your application
+// (Don't later try to change the sanitizer on the fly).
+func SetLogSanitizer(s LogSanitizer)(){
+	sanitizer = s
+}
+
+

pipeline/defaultlog.go

@@ -0,0 +1,11 @@
+package pipeline
+
+
+// ForceLog should rarely be used. It forceable logs an entry to the
+// Windows Event Log (on Windows) or to the SysLog (on Linux)
+func ForceLog(level LogLevel, msg string) {
+	if sanitizer != nil {
+		msg = sanitizer.SanitizeLogLine(msg)
+	}
+	forceLog(level, msg)
+}

pipeline/defaultlog_syslog.go

@@ -7,9 +7,9 @@ import (
 	"log/syslog"
 )
 
-// ForceLog should rarely be used. It forceable logs an entry to the
+// forceLog should rarely be used. It forceable logs an entry to the
 // Windows Event Log (on Windows) or to the SysLog (on Linux)
-func ForceLog(level LogLevel, msg string) {
+func forceLog(level LogLevel, msg string) {
 	if defaultLogger == nil {
 		return // Return fast if we failed to create the logger.
 	}

pipeline/defaultlog_windows.go

@@ -6,9 +6,9 @@ import (
 	"unsafe"
 )
 
-// ForceLog should rarely be used. It forceable logs an entry to the
+// forceLog should rarely be used. It forceable logs an entry to the
 // Windows Event Log (on Windows) or to the SysLog (on Linux)
-func ForceLog(level LogLevel, msg string) {
+func forceLog(level LogLevel, msg string) {
 	var el eventType
 	switch level {
 	case LogError, LogFatal, LogPanic: