logger.go

// Copyright 2021 Alex Szakaly
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

package logger

import (
	"log"

	"github.com/spf13/viper"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
)

// CreateLogger creates zap.Logger.
func CreateLogger() *zap.Logger {
	logLevel := func() zap.AtomicLevel {
		if viper.GetBool("debug") {
			return zap.NewAtomicLevelAt(zapcore.DebugLevel)
		}

		return zap.NewAtomicLevelAt(zapcore.InfoLevel)
	}()

	zapLogger, err := zap.Config{
		Level:       logLevel,
		Development: false,
		Encoding:    "json",
		EncoderConfig: zapcore.EncoderConfig{
			TimeKey:        "time",
			LevelKey:       "level",
			NameKey:        "logger",
			CallerKey:      "caller",
			MessageKey:     "msg",
			LineEnding:     zapcore.DefaultLineEnding,
			EncodeLevel:    zapcore.LowercaseLevelEncoder,
			EncodeTime:     zapcore.ISO8601TimeEncoder,
			EncodeDuration: zapcore.StringDurationEncoder,
			EncodeCaller:   zapcore.ShortCallerEncoder,
		},
		OutputPaths:      []string{"stdout"},
		ErrorOutputPaths: []string{"stderr"},
	}.Build()
	if err != nil {
		log.Fatalf("error creating zap logger parent %v", err) //nolint:revive // We must immediately exit, deep-exit.
	}

	defer zapLogger.Sync() //nolint:errcheck

	return zapLogger
}