[FAB-6272] SDK Go logging interface and provider

-added fabric api interface
-provided implementation in fabric pkg by using
standard go lang logging
-added AddCustomLogging() where a custom logger
can be plugged in
-test coverage : 92.2%


Change-Id: If7a1c2ed510806511d0da23b98c9617857ae4e2f
Signed-off-by: Sudesh Shetty <[email protected]>

api/apilogging/logger.go

@@ -0,0 +1,52 @@
+/*
+Copyright SecureKey Technologies Inc. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package apilogging
+
+//Logger - Standard logger interface
+type Logger interface {
+	Fatal(v ...interface{})
+
+	Fatalf(format string, v ...interface{})
+
+	Fatalln(v ...interface{})
+
+	Panic(v ...interface{})
+
+	Panicf(format string, v ...interface{})
+
+	Panicln(v ...interface{})
+
+	Print(v ...interface{})
+
+	Printf(format string, v ...interface{})
+
+	Println(v ...interface{})
+
+	Debug(args ...interface{})
+
+	Debugf(format string, args ...interface{})
+
+	Debugln(args ...interface{})
+
+	Info(args ...interface{})
+
+	Infof(format string, args ...interface{})
+
+	Infoln(args ...interface{})
+
+	Warn(args ...interface{})
+
+	Warnf(format string, args ...interface{})
+
+	Warnln(args ...interface{})
+
+	Error(args ...interface{})
+
+	Errorf(format string, args ...interface{})
+
+	Errorln(args ...interface{})
+}

pkg/logging/level.go

@@ -0,0 +1,94 @@
+/*
+Copyright SecureKey Technologies Inc. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package logging
+
+import (
+	"errors"
+	"strings"
+	"sync"
+)
+
+// ErrInvalidLogLevel is used when an invalid log level has been used.
+var ErrInvalidLogLevel = errors.New("logger: invalid log level")
+
+// Level defines all available log levels for log messages.
+type Level int
+
+// Log levels.
+const (
+	CRITICAL Level = iota
+	ERROR
+	WARNING
+	INFO
+	DEBUG
+)
+
+var levelNames = []string{
+	"CRITICAL",
+	"ERROR",
+	"WARNING",
+	"INFO",
+	"DEBUG",
+}
+
+// String returns the string representation of a logging level.
+func (p Level) String() string {
+	return levelNames[p]
+}
+
+// LogLevel returns the log level from a string representation.
+func LogLevel(level string) (Level, error) {
+	for i, name := range levelNames {
+		if strings.EqualFold(name, level) {
+			return Level(i), nil
+		}
+	}
+	return ERROR, ErrInvalidLogLevel
+}
+
+// Leveled interface is the interface required to be able to add leveled
+// logging.
+type Leveled interface {
+	GetLevel(string) Level
+	SetLevel(Level, string)
+	IsEnabledFor(Level, string) bool
+}
+
+type moduleLeveled struct {
+	sync.RWMutex
+	levels map[string]Level
+}
+
+// GetLevel returns the log level for the given module.
+func (l *moduleLeveled) GetLevel(module string) Level {
+	l.RLock()
+	defer l.RUnlock()
+	level, exists := l.levels[module]
+	if exists == false {
+		level, exists = l.levels[""]
+		// no configuration exists, default to info
+		if exists == false {
+			level = INFO
+		}
+	}
+	return level
+}
+
+// SetLevel sets the log level for the given module.
+func (l *moduleLeveled) SetLevel(level Level, module string) {
+	l.Lock()
+	defer l.Unlock()
+	if l.levels == nil {
+		l.levels = make(map[string]Level)
+	}
+	l.levels[module] = level
+}
+
+// IsEnabledFor will return true if logging is enabled for the given module.
+func (l *moduleLeveled) IsEnabledFor(level Level, module string) bool {
+	return level <= l.GetLevel(module)
+}

pkg/logging/level_test.go

@@ -0,0 +1,95 @@
+/*
+Copyright SecureKey Technologies Inc. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+package logging
+
+import (
+	"testing"
+)
+
+func TestLogLevels(t *testing.T) {
+
+	mlevel := moduleLeveled{}
+
+	mlevel.SetLevel(INFO, "module-xyz-info")
+	mlevel.SetLevel(DEBUG, "module-xyz-debug")
+	mlevel.SetLevel(ERROR, "module-xyz-error")
+	mlevel.SetLevel(WARNING, "module-xyz-warning")
+
+	//Run info level checks
+	verifyTrue(t, mlevel.IsEnabledFor(INFO, "module-xyz-info"))
+	verifyFalse(t, mlevel.IsEnabledFor(DEBUG, "module-xyz-info"))
+	verifyTrue(t, mlevel.IsEnabledFor(ERROR, "module-xyz-info"))
+	verifyTrue(t, mlevel.IsEnabledFor(WARNING, "module-xyz-info"))
+
+	//Run debug level checks
+	verifyTrue(t, mlevel.IsEnabledFor(INFO, "module-xyz-debug"))
+	verifyTrue(t, mlevel.IsEnabledFor(DEBUG, "module-xyz-debug"))
+	verifyTrue(t, mlevel.IsEnabledFor(ERROR, "module-xyz-debug"))
+	verifyTrue(t, mlevel.IsEnabledFor(WARNING, "module-xyz-debug"))
+
+	//Run info level checks
+	verifyFalse(t, mlevel.IsEnabledFor(INFO, "module-xyz-error"))
+	verifyFalse(t, mlevel.IsEnabledFor(DEBUG, "module-xyz-error"))
+	verifyTrue(t, mlevel.IsEnabledFor(ERROR, "module-xyz-error"))
+	verifyFalse(t, mlevel.IsEnabledFor(WARNING, "module-xyz-error"))
+
+	//Run info level checks
+	verifyFalse(t, mlevel.IsEnabledFor(INFO, "module-xyz-warning"))
+	verifyFalse(t, mlevel.IsEnabledFor(DEBUG, "module-xyz-warning"))
+	verifyTrue(t, mlevel.IsEnabledFor(ERROR, "module-xyz-warning"))
+	verifyTrue(t, mlevel.IsEnabledFor(WARNING, "module-xyz-warning"))
+
+	//Run default log level check --> which is info currently
+	verifyTrue(t, mlevel.IsEnabledFor(INFO, "module-xyz-random-module"))
+	verifyFalse(t, mlevel.IsEnabledFor(DEBUG, "module-xyz-random-module"))
+	verifyTrue(t, mlevel.IsEnabledFor(ERROR, "module-xyz-random-module"))
+	verifyTrue(t, mlevel.IsEnabledFor(WARNING, "module-xyz-random-module"))
+
+}
+
+func TestGetLogLevels(t *testing.T) {
+
+	level, err := LogLevel("info")
+	verifyLogLevel(t, INFO, level, err, true)
+
+	level, err = LogLevel("iNfO")
+	verifyLogLevel(t, INFO, level, err, true)
+
+	level, err = LogLevel("debug")
+	verifyLogLevel(t, DEBUG, level, err, true)
+
+	level, err = LogLevel("DeBuG")
+	verifyLogLevel(t, DEBUG, level, err, true)
+
+	level, err = LogLevel("warning")
+	verifyLogLevel(t, WARNING, level, err, true)
+
+	level, err = LogLevel("WarNIng")
+	verifyLogLevel(t, WARNING, level, err, true)
+
+	level, err = LogLevel("error")
+	verifyLogLevel(t, ERROR, level, err, true)
+
+	level, err = LogLevel("eRRoR")
+	verifyLogLevel(t, ERROR, level, err, true)
+
+	level, err = LogLevel("outofthebox")
+	verifyLogLevel(t, -1, level, err, false)
+
+	level, err = LogLevel("")
+	verifyLogLevel(t, -1, level, err, false)
+}
+
+func verifyLogLevel(t *testing.T, expectedLevel Level, currentlevel Level, err error, success bool) {
+	if success {
+		verifyEmpty(t, err, "not supposed to get error for this scenario")
+	} else {
+		verifyNotEmpty(t, err, "supposed to get error for this scenario, but got error : %v", err)
+		return
+	}
+
+	verifyTrue(t, currentlevel == expectedLevel, "unexpected log level : expected '%s', but got '%s'", expectedLevel, currentlevel)
+}