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How to use Error method of logger Package

Best Gauge code snippet using logger.Error

server.go

Source:server.go

...13	"github.com/friendsofgo/errors"14	"github.com/volatiletech/abcweb/v5/abcconfig"15	"go.uber.org/zap"16)17// ServerErrLogger allows us to use the zap.Logger as our http.Server ErrorLog18type ServerErrLogger struct {19	log *zap.Logger20}21// Implement Write to log server errors using the zap logger22func (s ServerErrLogger) Write(b []byte) (int, error) {23	s.log.Debug(string(b))24	return 0, nil25}26// StartServer starts the web server on the specified port, and can be27// gracefully shut down by sending an os.Interrupt signal to the server.28// This is a blocking call.29func StartServer(cfg abcconfig.ServerConfig, router http.Handler, logger *zap.Logger, kill chan struct{}) error {30	errs := make(chan error)31	// These start in goroutines and converge when we kill them32	primary := mainServer(cfg, router, logger, errs)33	var secondary *http.Server34	if len(cfg.TLSBind) != 0 && len(cfg.Bind) != 0 {35		secondary = redirectServer(cfg, logger, errs)36	}37	quit := make(chan os.Signal)38	signal.Notify(quit, os.Interrupt, os.Kill)39	select {40	case <-kill:41		logger.Info("internal shutdown initiated")42	case sig := <-quit:43		logger.Info("signal received, shutting down", zap.String("signal", sig.String()))44	case err := <-errs:45		logger.Error("error from server, shutting down", zap.Error(err))46	}47	if err := primary.Shutdown(context.Background()); err != nil {48		logger.Error("error shutting down http(s) server", zap.Error(err))49	}50	if secondary != nil {51		if err := secondary.Shutdown(context.Background()); err != nil {52			logger.Error("error shutting down redirector server", zap.Error(err))53		}54	}55	logger.Info("http(s) server shut down complete")56	return nil57}58func mainServer(cfg abcconfig.ServerConfig, router http.Handler, logger *zap.Logger, errs chan<- error) *http.Server {59	server := basicServer(cfg, logger)60	server.Handler = router61	useTLS := len(cfg.TLSBind) != 062	if !useTLS {63		server.Addr = cfg.Bind64		logger.Info("starting http listener", zap.String("bind", cfg.Bind))65		go func() {66			if err := server.ListenAndServe(); err != nil {67				errs <- errors.Wrap(err, "http listener died")68			}69		}()70		return server71	}72	server.Addr = cfg.TLSBind73	server.TLSConfig = &tls.Config{74		// Causes servers to use Go's default ciphersuite preferences,75		// which are tuned to avoid attacks. Does nothing on clients.76		PreferServerCipherSuites: true,77		// Only use curves which have assembly implementations78		CurvePreferences: []tls.CurveID{tls.CurveP256, tls.X25519},79	}80	logger.Info("starting https listener", zap.String("bind", cfg.TLSBind))81	go func() {82		if err := server.ListenAndServeTLS(cfg.TLSCertFile, cfg.TLSKeyFile); err != nil {83			errs <- errors.Wrap(err, "https listener died")84		}85	}()86	return server87}88func redirectServer(cfg abcconfig.ServerConfig, logger *zap.Logger, errs chan<- error) *http.Server {89	_, httpsPort, err := net.SplitHostPort(cfg.TLSBind)90	if err != nil {91		errs <- errors.Wrap(err, "http listener died")92		return nil93	}94	server := basicServer(cfg, logger)95	server.Addr = cfg.Bind96	server.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {97		var err error98		httpHost := r.Host99		// Remove port if it exists so we can replace it with https port100		if strings.ContainsRune(r.Host, ':') {101			httpHost, _, err = net.SplitHostPort(r.Host)102			if err != nil {103				logger.Error("failed to get http host from request", zap.String("host", r.Host), zap.Error(err))104				w.WriteHeader(http.StatusBadRequest)105				io.WriteString(w, "invalid host header")106				return107			}108		}109		var url string110		if httpsPort != "443" {111			url = fmt.Sprintf("https://%s:%s%s", httpHost, httpsPort, r.RequestURI)112		} else {113			url = fmt.Sprintf("https://%s%s", httpHost, r.RequestURI)114		}115		logger.Info("redirect", zap.String("remote", r.RemoteAddr), zap.String("host", r.Host), zap.String("path", r.URL.String()), zap.String("redirecturl", url))116		http.Redirect(w, r, url, http.StatusMovedPermanently)117	})118	logger.Info("starting http listener", zap.String("bind", cfg.Bind))119	go func() {120		if err := server.ListenAndServe(); err != nil {121			errs <- errors.Wrap(err, "http listener died")122		}123	}()124	return server125}126func basicServer(cfg abcconfig.ServerConfig, logger *zap.Logger) *http.Server {127	server := &http.Server{128		ReadTimeout:  cfg.ReadTimeout,129		WriteTimeout: cfg.WriteTimeout,130		IdleTimeout:  cfg.IdleTimeout,131		ErrorLog:     log.New(ServerErrLogger{log: logger}, "", 0),132	}133	return server134}...

tm_logger.go

Source:tm_logger.go

...43// Info logs a message at level Info.44func (l *tmLogger) Info(msg string, keyvals ...interface{}) {45	lWithLevel := kitlevel.Info(l.srcLogger)46	if err := kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...); err != nil {47		errLogger := kitlevel.Error(l.srcLogger)48		kitlog.With(errLogger, msgKey, msg).Log("err", err)49	}50}51// Debug logs a message at level Debug.52func (l *tmLogger) Debug(msg string, keyvals ...interface{}) {53	lWithLevel := kitlevel.Debug(l.srcLogger)54	if err := kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...); err != nil {55		errLogger := kitlevel.Error(l.srcLogger)56		kitlog.With(errLogger, msgKey, msg).Log("err", err)57	}58}59// Error logs a message at level Error.60func (l *tmLogger) Error(msg string, keyvals ...interface{}) {61	lWithLevel := kitlevel.Error(l.srcLogger)62	lWithMsg := kitlog.With(lWithLevel, msgKey, msg)63	if err := lWithMsg.Log(keyvals...); err != nil {64		lWithMsg.Log("err", err)65	}66}67// With returns a new contextual logger with keyvals prepended to those passed68// to calls to Info, Debug or Error.69func (l *tmLogger) With(keyvals ...interface{}) Logger {70	return &tmLogger{kitlog.With(l.srcLogger, keyvals...)}71}...

tracing_logger.go

Source:tracing_logger.go

...3	"fmt"4	"github.com/pkg/errors"5)6// NewTracingLogger enables tracing by wrapping all errors (if they7// implement stackTracer interface) in tracedError.8//9// All errors returned by https://github.com/pkg/errors implement stackTracer10// interface.11//12// For debugging purposes only as it doubles the amount of allocations.13func NewTracingLogger(next Logger) Logger {14	return &tracingLogger{15		next: next,16	}17}18type stackTracer interface {19	error20	StackTrace() errors.StackTrace21}22type tracingLogger struct {23	next Logger24}25func (l *tracingLogger) Info(msg string, keyvals ...interface{}) {26	l.next.Info(msg, formatErrors(keyvals)...)27}28func (l *tracingLogger) Debug(msg string, keyvals ...interface{}) {29	l.next.Debug(msg, formatErrors(keyvals)...)30}31func (l *tracingLogger) Error(msg string, keyvals ...interface{}) {32	l.next.Error(msg, formatErrors(keyvals)...)33}34func (l *tracingLogger) With(keyvals ...interface{}) Logger {35	return &tracingLogger{next: l.next.With(formatErrors(keyvals)...)}36}37func formatErrors(keyvals []interface{}) []interface{} {38	newKeyvals := make([]interface{}, len(keyvals))39	copy(newKeyvals, keyvals)40	for i := 0; i < len(newKeyvals)-1; i += 2 {41		if err, ok := newKeyvals[i+1].(stackTracer); ok {42			newKeyvals[i+1] = tracedError{err}43		}44	}45	return newKeyvals46}47// tracedError wraps a stackTracer and just makes the Error() result48// always return a full stack trace.49type tracedError struct {50	wrapped stackTracer51}52var _ stackTracer = tracedError{}53func (t tracedError) StackTrace() errors.StackTrace {54	return t.wrapped.StackTrace()55}56func (t tracedError) Cause() error {57	return t.wrapped58}59func (t tracedError) Error() string {60	return fmt.Sprintf("%+v", t.wrapped)61}...

Error

Using AI Code Generation

1import (2func main() {3    f, err := os.Create("error.log")4    if err != nil {5        log.Fatal(err)6    }7    log.SetOutput(f)8    log.SetFlags(log.LstdFlags | log.Lshortfile)9    log.Println("This is a normal message")10    log.Fatalln("This is a fatal message")11    log.Panicln("This is a panic message")12}13import (14func main() {15    f, err := os.Create("fatal.log")16    if err != nil {17        log.Fatal(err)18    }19    log.SetOutput(f)20    log.SetFlags(log.LstdFlags | log.Lshortfile)21    log.Println("This is a normal message")22    log.Fatalln("This is a fatal message")23    log.Panicln("This is a panic message")24}25import (26func main() {27    f, err := os.Create("panic.log")28    if err != nil {29        log.Fatal(err)30    }31    log.SetOutput(f)32    log.SetFlags(log.LstdFlags | log.Lshortfile)33    log.Println("This is a normal message")34    log.Fatalln("This is a fatal message")35    log.Panicln("This is a panic message")36}

Error

Using AI Code Generation

1import (2func main() {3	logFile, err := os.OpenFile("logFile.txt", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)4	if err != nil {5		log.Fatalln("failed to open error log file:", err)6	}7	defer logFile.Close()8	logger := log.New(logFile, "logger: ", log.Lshortfile)9	logger.Println("This is a regular message.")10	logger.Fatalln("This is a fatal error.")11}

Error

Using AI Code Generation

1log.Error("Error message")2log.Info("Info message")3log.Debug("Debug message")4log.Warn("Warn message")5log.Fatal("Fatal message")6log.Panic("Panic message")7log.Print("Print message")8log.Panic(0xc42000c0b0, 0x1, 0x1)9main.main()10runtime.goexit()

Error

Using AI Code Generation

1import (2func main() {3	f, err := os.Create("test.log")4	if err != nil {5		log.Fatal(err)6	}7	defer f.Close()8	logger := log.New(f, "logger: ", log.Lshortfile)9	logger.Print("This is a regular message.")10	logger.Error("This is an error message.")11}12import (13func main() {14	f, err := os.Create("test.log")15	if err != nil {16		log.Fatal(err)17	}18	defer f.Close()19	logger := log.New(f, "logger: ", log.Lshortfile)20	logger.Print("This is a regular message.")21	logger.Fatal("This is an error message.")22}23import (24func main() {25	f, err := os.Create("test.log")26	if err != nil {27		log.Fatal(err)28	}29	defer f.Close()30	logger := log.New(f, "logger: ", log.Lshortfile)31	logger.Print("This is a regular message.")32	logger.Panic("This is an error message.")33}

Error

Using AI Code Generation

1import (2func main() {3	file, err := os.Open("test.txt")4	if err != nil {5		log.Fatal("Error in opening file", err)6	}7	defer file.Close()8}9import (10func main() {11	file, err := os.Open("test.txt")12	if err != nil {13		log.Fatalf("Error in opening file %s", err)14	}15	defer file.Close()16}17import (18func main() {19	file, err := os.Open("test.txt")20	if err != nil {21		log.Fatalln("Error in opening file", err)22	}23	defer file.Close()24}25import (26func main() {27	file, err := os.Open("test.txt")28	if err != nil {29		log.Fatal("Error in opening file", err)30	}31	defer file.Close()32}33import (34func main() {35	file, err := os.Open("test.txt")36	if err != nil {37		log.Fatalf("Error in opening file %s", err)38	}39	defer file.Close()40}

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