Allow custom levelers for grpc interceptors

The logging interceptors can now be provided with options that enable
custom logging levels for log messages and payloads.

Introduced Payload and Disabled logging levels. The Payload level will
be the default level used to log grpc message contents. It should be
extremely rare that this information is needed. The Disabled level can
be used programmatically to completely disable a logger.

The orderer main is updated to exploit the leveler option to disable any
grpc logging for Step function of the orderer.Cluster service.

FAB-12952 #done
FAB-12933 #done

Change-Id: Id1e39762b2cbd3a317a0710d0b229559dd7807a3
Signed-off-by: Matthew Sykes <[email protected]>

common/flogging/levels.go

@@ -8,10 +8,21 @@ package flogging
 
 import (
 	"fmt"
+	"math"
 
 	"go.uber.org/zap/zapcore"
 )
 
+const (
+	// DisabledLevel represents a disabled log level. Logs at this level should
+	// never be emitted.
+	DisabledLevel = zapcore.Level(math.MinInt8)
+
+	// PayloadLevel is used to log the extremely detailed message level debug
+	// information.
+	PayloadLevel = zapcore.Level(zapcore.DebugLevel - 1)
+)
+
 // NameToLevel converts a level name to a zapcore.Level.  If the level name is
 // unknown, zapcore.InfoLevel is returned.
 func NameToLevel(level string) zapcore.Level {
@@ -24,6 +35,8 @@ func NameToLevel(level string) zapcore.Level {
 
 func nameToLevel(level string) (zapcore.Level, error) {
 	switch level {
+	case "PAYLOAD", "payload":
+		return PayloadLevel, nil
 	case "DEBUG", "debug":
 		return zapcore.DebugLevel, nil
 	case "INFO", "info":
@@ -45,7 +58,7 @@ func nameToLevel(level string) (zapcore.Level, error) {
 		return zapcore.ErrorLevel, nil // future
 
 	default:
-		return zapcore.Level(-99), fmt.Errorf("invalid log level: %s", level)
+		return DisabledLevel, fmt.Errorf("invalid log level: %s", level)
 	}
 }
 

common/flogging/levels_test.go

@@ -19,6 +19,7 @@ func TestNameToLevel(t *testing.T) {
 		names []string
 		level zapcore.Level
 	}{
+		{names: []string{"PAYLOAD", "payload"}, level: flogging.PayloadLevel},
 		{names: []string{"DEBUG", "debug"}, level: zapcore.DebugLevel},
 		{names: []string{"INFO", "info"}, level: zapcore.InfoLevel},
 		{names: []string{"WARNING", "warning", "WARN", "warn"}, level: zapcore.WarnLevel},
@@ -42,6 +43,7 @@ func TestNameToLevel(t *testing.T) {
 
 func TestIsValidLevel(t *testing.T) {
 	validNames := []string{
+		"PAYLOAD", "payload",
 		"DEBUG", "debug",
 		"INFO", "info",
 		"WARNING", "warning",
@@ -62,6 +64,7 @@ func TestIsValidLevel(t *testing.T) {
 	invalidNames := []string{
 		"george", "bob",
 		"warnings", "inf",
+		"DISABLED", "disabled", // can only be used programmatically
 	}
 	for _, name := range invalidNames {
 		t.Run(name, func(t *testing.T) {