Golang Packages

Overview #

• Cobra, Viper, GoDotEnv, Lumberjack, ZeroLog, LogRUs, Alice, Gorilla (Handlers / Mux), GDDO, Slug
• Jwt, Unleash, Pulsar, Mongo
• Go Text Gen

Extremely useful #

• github.com/spf13/cobra v1.2.1
  • framework to make command line tools
• github.com/spf13/viper v1.8.1
  • framework for config management
  • flexible and easy when dealing with files or command line params
  • not very easy to extend to deal with central config server (Java SCCS or Consul)
• github.com/joho/godotenv v1.3.0
  • easy loading of environment variables and various files
• github.com/natefinch/lumberjack v2.0.0+incompatible
  • makes it easy to pipe logs to various streams simultaneously (e.g. console + file)

  // log.go
  package util
  import (
    "os"
    "strings"
    "time"
  
    "github.com/natefinch/lumberjack"
    "github.com/rs/zerolog"
    "github.com/spf13/viper"
  )
  
  func NewLogger() *zerolog.Logger {
    var cw *zerolog.ConsoleWriter
    var fw *lumberjack.Logger
    if viper.GetBool("log.console.enabled") {
      cw = &zerolog.ConsoleWriter{Out: os.Stdout, TimeFormat: time.RFC1123}
    }
  
    if viper.GetBool("log.file.enabled") {
      if strings.Compare(viper.GetString("log.file.name"), "") == 0 {
        viper.Set("log.file.name", "out.log")
        viper.WriteConfig()
      }
      fw = &lumberjack.Logger{
        Filename:   viper.GetString("log.file.name"),
        MaxBackups: viper.GetInt("log.file.backups"),
        MaxSize:    viper.GetInt("log.file.size"),
        MaxAge:     viper.GetInt("log.file.days"),
      }
    }
  
    if viper.GetBool("debug.enabled") {
      zerolog.SetGlobalLevel(zerolog.DebugLevel)
    } else {
      zerolog.SetGlobalLevel(zerolog.InfoLevel)
    }
  
    multi := zerolog.MultiLevelWriter(cw, fw)
  
    log := zerolog.New(multi).With().Timestamp().Logger()
  
    return &log
  }
  

• github.com/rs/zerolog v1.23.0
  • like this because it was easy to wrap requests and trace them from the router down through the various layers
  • hlog assigns a request ID for each request (see alice example below)
• github.com/sirupsen/logrus v1.7.0
  • started using this logger first per these tutorials by Nic Jackson but moved to zerolog
• github.com/justinas/alice v1.2.0
  • alice makes chaining midware together simpler and cleaner

  chain := alice.New()
  chain = chain.Append(hlog.NewHandler(*log))
  chain = chain.Append(hlog.RemoteAddrHandler("ip"))
    chain = chain.Append(hlog.UserAgentHandler("user_agent"))
    chain = chain.Append(hlog.RefererHandler("referer"))
    chain = chain.Append(hlog.RequestIDHandler("req_id", "Request-Id"))
  handler := chain.Then(sm)
  

• github.com/gorilla/handlers v1.5.1
  • midware to handle CORS

  import gohandlers "github.com/gorilla/handlers"
    corsWrapper := gohandlers.CORS(
    	gohandlers.AllowedOrigins([]string{"*"}),
    	gohandlers.AllowedHeaders([]string{"Content-Type"}),
    	gohandlers.AllowedMethods([]string{"GET", "HEAD", "POST", "PUT", "OPTIONS"}),
    )
    srv := http.Server{
    	Addr:         bindAddress + port,
    	Handler:      corsWrapper(handler),
    }
  

• github.com/gorilla/mux v1.8.0
  • mux allowed me to create open router + secure / password protected routes

  // InitRouters sets up both secure and open routers
  func InitRouters(log *zerolog.Logger, sh *Handler) *mux.Router {
    sm := mux.NewRouter()
    log.Debug().Msg("Setting route / method handling")
    newRouterSetUp(sm, sh)
    newSecureRouterSetUp(sm, sh, log)
  
    // swagger:route GET /error default notFound
    // Return custom not found message
    // responses:
    //	404: errorResponse
    sm.NotFoundHandler = sm.NewRoute().HandlerFunc(sh.NotFound).GetHandler()
  
    return sm
  }
  // newRouterSetUp creates a new Router with all of the unsecured subRouters required for the API
  func newRouterSetUp(sm *mux.Router, sh *Handler) {
  
    // swagger:route GET / default getRoot
    // Return default success message
    // responses:
    //	200: successResponse
    getRootRouter := sm.Methods(http.MethodGet, http.MethodOptions).Subrouter()
    getRootRouter.HandleFunc("", sh.GetRoot)
    getRootRouter.HandleFunc("/", sh.GetRoot)
  }
  // newSecureRouterSetUp creates a new Router with all of the secured subRouters required for the API
  func newSecureRouterSetUp(sm *mux.Router, sh *Handler, log *zerolog.Logger) {
  
    r := sm.PathPrefix("/api").Subrouter()
  
    // GET /api/cars
    listCarsRouter := r.PathPrefix("/cars").Methods(http.MethodGet, http.MethodOptions).Subrouter()
    listCarsRouter.HandleFunc("", util.ValidateApiKey(sh.GetCars))
    listCarsRouter.HandleFunc("/", util.ValidateApiKey(sh.GetCars))
  
    // swagger:route POST /cars cars importCars
    // Create multiple new hashCars
    // Requires emails array in body
    // responses:
    //	200: successResponse
    addCarsRouter := r.PathPrefix("/cars").Methods(http.MethodPost, http.MethodOptions).Subrouter()
    addCarsRouter.Path("").HandlerFunc(util.ValidateApiKey(sh.AddCars))
    addCarsRouter.Path("/").HandlerFunc(util.ValidateApiKey(sh.AddCars))
    }
  

• github.com/golang/gddo v0.0.0-20200831202555-721e228c7686
  • contains httputil/header package which is useful in setting header values in REST response
• github.com/gosimple/slug v1.9.0
  • slugifies strings (e.g. This is Rishi's Blog -> this-is-rishis-blog)

Project / Technology specific #

• github.com/golang-jwt/jwt v3.2.1+incompatible
  • helps with generating and parsing JSON Web Tokens
• github.com/Unleash/unleash-client-go/v3 v3.2.3
  • Easy way to handle feature flags using the Unleash server (built into Gitlab)
• github.com/apache/pulsar-client-go v0.3.0
  • Apache Pulsar client for real-time streaming messages
• go.mongodb.org/mongo-driver v1.6.0
  • Mongo DB driver (NoSQL Document database)

Mine 🎉 #

• gitlab.com/rshmhrj/go-text-gen v0.0.0-20210205104829-3c5cbc355961
  • Easily generate text strings for use in other projects:
    • 404 messages
    • random names for instances of stuff