zDWSI/defaultFrontend/main.go

package main

import (
	"fmt"
	"gopkg.in/natefinch/lumberjack.v2"
	"gopkg.in/yaml.v2"
	"io/ioutil"
	"os"
)

var ListenAddress string
var WWWRootPath string
var BackendPrefix string
var BackendTarget string

var ConfigData FrontendConfigYAML
var AccessLogLevelConfigData *AccessLoggerLevelConfig
var ErrorLogOutputLevel DWSILogLevel

var AccessLog *AccessLogger
var ErrorLog *CommonLogger

func main() {
	fmt.Println("--- zDWSI Default Frontend ---")
	GetConfigEnv()
	ParseYAMLConfig()
	InitLogger()
	StartServer()
}

func GetConfigEnv() {
	fmt.Println("Get Basic Config From Environment Variables...")
	ListenAddress = os.Getenv("listen")
	WWWRootPath = os.Getenv("wwwroot")
	BackendPrefix = os.Getenv("backend_prefix")
	BackendTarget = os.Getenv("backend_target")
	if ListenAddress == "" {
		fmt.Println("No environment variable 'listen', use default value ':8080'")
		ListenAddress = ":8080"
	}
	if WWWRootPath == "" {
		fmt.Println("No environment variable 'wwwroot', use default value '/data/wwwroot/'")
		WWWRootPath = "/data/wwwroot/"
	}
	if BackendPrefix == "" {
		fmt.Println("No environment variable 'backend_prefix', use default value 'api'")
		BackendPrefix = "api"
	}
	if BackendTarget == "" {
		fmt.Println("No environment variable 'backend_target', use default value 'http://localhost:9090/'")
		BackendTarget = "http://localhost:9090/"
	}
	fmt.Println("Listen Address: ", ListenAddress)
	fmt.Println("WWW Root Path: ", WWWRootPath)
	fmt.Println("Backend Prefix: ", BackendPrefix)
	fmt.Println("Backend Route Path: ", fmt.Sprintf("/%s/", BackendPrefix))
	fmt.Println("Backend Proxy Target: ", BackendTarget)
}

func ParseYAMLConfig() {
	fmt.Println("Load Config '/data/frontend/zdwsi.frontend.config.yaml'...")
	jdata, err := ioutil.ReadFile("/data/frontend/zdwsi.frontend.config.yaml")
	if err != nil {
		fmt.Println("failed read config file: ", err)
		os.Exit(ExitCode_YAMLFileReadError)
	}
	err = yaml.Unmarshal(jdata, &ConfigData)
	if err != nil {
		fmt.Println("failed parse config YAML: ", err)
		os.Exit(ExitCode_YAMLParseError)
	}
	err, AccessLogLevelConfigData = ConvertLogLevelConfig(ConfigData.LogConfig.AccessLoggerDetailConfig)
	if err != nil {
		fmt.Println("failed parse config YAML in semantics: ", err)
		os.Exit(ExitCode_YAMLSemanticsError)
	}
	ErrorLogOutputLevel = transLevelStringIntoLevel(ConfigData.LogConfig.ErrorLoggerDetailConfig.OutputLevel)
	fmt.Println("Config Loaded.")
	err = yaml.Unmarshal(jdata, &ConfigData)
	if err != nil {
		fmt.Println("failed parse config YAML: ", err)
		os.Exit(ExitCode_YAMLParseError)
	}
	if ConfigData.CommonConfig.IsDebugModeOn {
		fmt.Println("Debug Mode is Enable.")
		fmt.Println("Print All Config For Debug:")
		tmpyaml, err := yaml.Marshal(ConfigData)
		if err != nil {
			fmt.Println("Failed Print Config: ", err)
		} else {
			fmt.Printf("%v\n\n", string(tmpyaml))
		}
	}
}

func InitLogger() {
	cfg := ConfigData.LogConfig.RollingLogConfig.ErrLogCfg
	elw := &lumberjack.Logger{
		Filename:   cfg.FileName,
		MaxSize:    cfg.MaxSize,
		MaxAge:     cfg.MaxAge,
		MaxBackups: cfg.MaxBackups,
		LocalTime:  cfg.UseLocalTime,
		Compress:   cfg.Compress,
	}
	_, _ = fmt.Fprintln(elw, "Lumberjack Logger Write Test")
	ErrorLog = NewCommonLogger(ErrorLogOutputLevel, elw)
	ErrorLog.SetFormatter(
		ConfigData.LogConfig.ErrorLoggerDetailConfig.LogFormat,
		ConfigData.LogConfig.ErrorLoggerDetailConfig.UseUTC,
	)
	cfg = ConfigData.LogConfig.RollingLogConfig.AccessLogCfg
	AccessLog = NewAccessLogger()
	if ConfigData.LogConfig.AccessLogEnable {
		alw := &lumberjack.Logger{
			Filename:   cfg.FileName,
			MaxSize:    cfg.MaxSize,
			MaxAge:     cfg.MaxAge,
			MaxBackups: cfg.MaxBackups,
			LocalTime:  cfg.UseLocalTime,
			Compress:   cfg.Compress,
		}
		AccessLog.UseLogger(
			alw,
			AccessLogLevelConfigData,
			ConfigData.LogConfig.AccessLoggerDetailConfig.LogFormat,
			ConfigData.LogConfig.AccessLoggerDetailConfig.UseUTC,
		)
	}
}