Add log system

go.mod

@@ -16,4 +16,5 @@ require (
 	github.com/rubenv/sql-migrate v0.0.0-20200616145509-8d140a17f351
 	github.com/russross/meddler v1.0.0
 	github.com/stretchr/testify v1.6.1
+	go.uber.org/zap v1.13.0
 )

go.sum

@@ -539,11 +539,14 @@ go.opencensus.io v0.20.2/go.mod h1:6WKK9ahsWS3RSO+PY9ZHZUfv2irvY6gN279GOPZjmmk=
 go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
+go.uber.org/atomic v1.5.0 h1:OI5t8sDa1Or+q8AeE+yKeB/SDYioSHAgcVljj9JIETY=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
+go.uber.org/multierr v1.3.0 h1:sFPn2GLc3poCkfrpIXGhBD2X0CMIo4Q/zSULXrj/+uc=
 go.uber.org/multierr v1.3.0/go.mod h1:VgVr7evmIr6uPjLBxg28wmKNXyqE9akIJ5XnfpiKl+4=
 go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee/go.mod h1:vJERXedbb3MVM5f9Ejo0C68/HhF8uaILCdgjnY+goOA=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
+go.uber.org/zap v1.13.0 h1:nR6NoDBgAf67s68NhaXbsojM+2gxp3S1hWkHDl27pVU=
 go.uber.org/zap v1.13.0/go.mod h1:zwrFLgMcdUuIBviXEYEH1YKNaOBnKXsx2IPda5bBwHM=
 golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=

log/log.go

@@ -0,0 +1,121 @@
+package log
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+var log *zap.SugaredLogger
+
+// errorsFile is the file where the errors are being written
+var errorsFile *os.File
+
+func init() {
+	// default level: debug
+	Init("debug", "")
+}
+
+// Init the logger with defined level. errorsPath defines the file where to store the errors, if set to "" will not store errors.
+func Init(levelStr, errorsPath string) {
+	var level zap.AtomicLevel
+	err := level.UnmarshalText([]byte(levelStr))
+	if err != nil {
+		panic(fmt.Errorf("Error on setting log level: %s", err))
+	}
+	cfg := zap.Config{
+		Level:            level,
+		Encoding:         "console",
+		OutputPaths:      []string{"stdout"},
+		ErrorOutputPaths: []string{"stderr"},
+		EncoderConfig: zapcore.EncoderConfig{
+			MessageKey: "message",
+
+			LevelKey:    "level",
+			EncodeLevel: zapcore.CapitalColorLevelEncoder,
+
+			TimeKey: "timestamp",
+			EncodeTime: func(ts time.Time, encoder zapcore.PrimitiveArrayEncoder) {
+				encoder.AppendString(ts.Local().Format(time.RFC3339))
+			},
+			EncodeDuration: zapcore.SecondsDurationEncoder,
+
+			CallerKey:    "caller",
+			EncodeCaller: zapcore.ShortCallerEncoder,
+
+			StacktraceKey: "stacktrace",
+			LineEnding:    zapcore.DefaultLineEnding,
+		},
+	}
+
+	logger, err := cfg.Build()
+	if err != nil {
+		panic(err)
+	}
+	//nolint:errcheck
+	defer logger.Sync()
+	log = logger.Sugar()
+
+	if errorsPath != "" {
+		log.Infof("file where errors will be written: %s", errorsPath)
+		errorsFile, err = os.OpenFile(errorsPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	log.Infof("log level: %s", level)
+}
+
+func writeToErrorsFile(msg string) {
+	if errorsFile == nil {
+		return
+	}
+	//nolint:errcheck
+	errorsFile.WriteString(fmt.Sprintf("%s %s\n", time.Now().Format(time.RFC3339), msg))
+}
+
+// Debug calls log.Debug
+func Debug(args ...interface{}) {
+	log.Debug(args...)
+}
+
+// Info calls log.Info
+func Info(args ...interface{}) {
+	log.Info(args...)
+}
+
+// Warn calls log.Warn
+func Warn(args ...interface{}) {
+	log.Warn(args...)
+}
+
+// Error calls log.Error and stores the error message into the ErrorFile
+func Error(args ...interface{}) {
+	log.Error(args...)
+	go writeToErrorsFile(fmt.Sprint(args...))
+}
+
+// Debugf calls log.Debugf
+func Debugf(template string, args ...interface{}) {
+	log.Debugf(template, args...)
+}
+
+// Infof calls log.Infof
+func Infof(template string, args ...interface{}) {
+	log.Infof(template, args...)
+}
+
+// Warnf calls log.Warnf
+func Warnf(template string, args ...interface{}) {
+	log.Warnf(template, args...)
+}
+
+// Errorf calls log.Errorf and stores the error message into the ErrorFile
+func Errorf(template string, args ...interface{}) {
+	log.Errorf(template, args...)
+	go writeToErrorsFile(fmt.Sprintf(template, args...))
+}

log/log_test.go

@@ -0,0 +1,14 @@
+package log
+
+import (
+	"testing"
+)
+
+func TestLog(t *testing.T) {
+	Info("Test log.Infow", "value", 10)
+	Infof("Test log.Infof %d", 10)
+	Debugf("Test log.Debugf %d", 10)
+	Error("Test log.Error", "value", 10)
+	Errorf("Test log.Errorf %d", 10)
+	Warnf("Test log.Warnf %d", 10)
+}