[#19] Add a version with no cdn-sdk deps

Signed-off-by: Pavel Korotkov <pavel@nspcc.ru>

logger/zap.go

@@ -0,0 +1,131 @@
+package logger
+
+import (
+	"strings"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+type (
+	Option func(o *options)
+
+	options struct {
+		Options []zap.Option
+
+		SamplingInitial    int
+		SamplingThereafter int
+
+		Format     string
+		Level      string
+		TraceLevel string
+
+		NoCaller     bool
+		NoDisclaimer bool
+
+		AppName    string
+		AppVersion string
+	}
+)
+
+const (
+	formatJSON    = "json"
+	formatConsole = "console"
+
+	defaultSamplingInitial    = 100
+	defaultSamplingThereafter = 100
+
+	lvlInfo  = "info"
+	lvlWarn  = "warn"
+	lvlDebug = "debug"
+	lvlError = "error"
+	lvlFatal = "fatal"
+	lvlPanic = "panic"
+)
+
+func safeLevel(lvl string) zap.AtomicLevel {
+	switch strings.ToLower(lvl) {
+	case lvlDebug:
+		return zap.NewAtomicLevelAt(zap.DebugLevel)
+	case lvlWarn:
+		return zap.NewAtomicLevelAt(zap.WarnLevel)
+	case lvlError:
+		return zap.NewAtomicLevelAt(zap.ErrorLevel)
+	case lvlFatal:
+		return zap.NewAtomicLevelAt(zap.FatalLevel)
+	case lvlPanic:
+		return zap.NewAtomicLevelAt(zap.PanicLevel)
+	default:
+		return zap.NewAtomicLevelAt(zap.InfoLevel)
+	}
+}
+
+func defaults() *options {
+	return &options{
+		SamplingInitial:    defaultSamplingInitial,
+		SamplingThereafter: defaultSamplingThereafter,
+
+		Format:     formatConsole,
+		Level:      lvlDebug,
+		TraceLevel: lvlInfo,
+
+		NoCaller:     false,
+		NoDisclaimer: false,
+
+		AppName:    "",
+		AppVersion: "",
+	}
+}
+
+func New(opts ...Option) (*zap.Logger, error) {
+	o := defaults()
+	c := zap.NewProductionConfig()
+
+	c.OutputPaths = []string{"stdout"}
+	c.ErrorOutputPaths = []string{"stdout"}
+
+	for _, opt := range opts {
+		opt(o)
+	}
+
+	// set sampling
+	c.Sampling = &zap.SamplingConfig{
+		Initial:    o.SamplingInitial,
+		Thereafter: o.SamplingThereafter,
+	}
+
+	// logger level
+	c.Level = safeLevel(o.Level)
+	traceLvl := safeLevel(o.TraceLevel)
+
+	// logger format
+	switch f := o.Format; strings.ToLower(f) {
+	case formatConsole:
+		c.Encoding = formatConsole
+	default:
+		c.Encoding = formatJSON
+	}
+
+	// logger time
+	c.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
+
+	if o.NoCaller {
+		c.EncoderConfig.EncodeCaller = nil
+	}
+
+	// enable trace only for current log-level
+	o.Options = append(o.Options, zap.AddStacktrace(traceLvl))
+
+	l, err := c.Build(o.Options...)
+	if err != nil {
+		return nil, err
+	}
+
+	if o.NoDisclaimer {
+		return l, nil
+	}
+
+	return l.With(
+		zap.String("app_name", o.AppName),
+		zap.String("app_version", o.AppVersion)), nil
+}